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Plants are extremely sensitive to changes in their environment, particularly variations in photoperiod or day length. Photoperiodism refers to a plant's capacity to detect variations in day length and make use of this knowledge to control key developmental processes including flowering, growth, and dormancy. Through a process known as photoperiodism, plants can detect and react to variations in the number of daylight hours, or photoperiod. The physiological response of plants to the length of day or night is known as photoperiodism. The plant uses this physiological response to time-critical developmental events like flowering. In this essay, I will cover the current understanding of how plants respond to photoperiod and the molecular mechanisms underpinning this response. Three groups of plants' photoperiodic responses can be distinguished: short-day plants (SDPs), long-day plants (LDPs), and day-neutral plants (DNPs). Whereas LDPs bloom when the length of the day exceeds the crucial threshold, SDPs do so only when it is shorter than the critical threshold. Conversely, DNPs do not have a crucial day duration and can bloom at any day length. Many genes and biochemical processes control how a plant responds to the photoperiod. The creation and movement of the hormone florigen, which starts blooming in response to photoperiodic signals, is a crucial regulating mechanism. On the other hand, a class of photoreceptors known as phytochromes is involved in the biochemical mechanisms driving photoperiodic responses in plants. The perception of light's duration, quality, and amount is caused by phytochromes. The red-light-absorbing Pr form and the far-red-light-absorbing Pfr form are the two interconvertible states in which they can exist. The ratio of Pr to Pfr is altered by the duration of light exposure and is utilizes by plants to assess day length. Exposure to light in SDPs causes the expression of the CONSTANS (CO) gene, and the CO protein causes the expression of the FLOWERING LOCUS T (FT), a gene that encourages flowering. By exposing LDPs to light, a different gene called GI (GIGANTEA) is induced rather than CO, which is normally expressed. The FT gene's expression is encouraged by GI's interaction with the protein ZEITLUPE (ZTL), which also encourages flowering. In addition to these essential elements, several proteins and signalling pathways are also involved in photoperiodic responses in plants. For instance, to optimise the response to variations in day length, the photoperiodic pathway interacts with the circadian clock, which controls numerous physiological processes in plants. In some species, the hormone gibberellin (GA) also aids in the promotion of flowering. One essential adaptation that enables plants to synchronize their developmental processes with seasonal changes is their capacity to react to variations in day length. Phytochromes play a key role in how plants perceive the day in the complex network of proteins and signalling channels that make up the molecular mechanisms behind photoperiodic responses in plants. There is still much to learn about the diversity and complexity of the photoperiodic response across several plant groupings, even if much is known about it in particular species.
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@#Introduction: Biomass microalgae functional materials, such as drugs and food supplements, have recently received much attention. Euglena sp. is a particularly appealing microalgae because of its simplicity of culture and capacity to produce a wide range of bioactive compounds. Moreover, it is one of the few microorganisms that produces carbohydrate, lipid, protein, ß-1,3-glucans, antioxidants, phytotoxins, wax esters, and polyunsaturated fatty acids that can be used to make nutraceuticals, pharmaceuticals, and cosmeceuticals. However, the potential utilisation of Euglena sp. for production of food supplements has been exploited only on a limited basis. Methods: This study was modified by adding protocatechuic acid and photoperiodism for 12:12; 14:10; 16:8; and full dark to affect the metabolite content of Euglenasp. Results: Results showed that the photoperiod had significant effect on lipid, chlorophyll-a, and carotenoid levels in the control treatment, with the highest levels as follows: 0.52±0.03 g/L, 1.20±0.01 x10-2 g/L, 0.30±0.02 x10-2 g/L; while the others were not significantly affected by the treatment, with the highest protein content at full dark 3.10±0.2 x10-2 g/L; chlorophyll-b at photoperiod 14:10 0.70±0.03 x10-2 g/L; paramylon at photoperiod 12:12 1.90±0.02 x10-1 g/L. The highest carbohydrates were found in control, with a level of 1.20±0.02 g/L. Conclusion: Photoperiodism is recommended to enhance productivity of protein, paramylon, and chlorophyll-b, while full light is recommended to enhance carbohydrate, lipid, chlorophyll-a, and carotenoid production in Euglena sp. to improve the quality of food nutrition.
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OBJECTIVE: To analyze the effects and the underlying mechanisms of photoperiodism and exposure to bisphenol A(BPA) on hepatic lipid metabolism in female mice. METHODS: A 2×2 factorial design was used. The photoperiod factor was set to fixed and shifted photoperiod, and the BPA factor was set to BPA exposure(BPA group) and non-exposure(control group). Specific pathogen free female C57 BL/6 J mice were randomly divided into four groups: fixed photoperiod control group, shifted photoperiod control group, fixed photoperiod BPA group, and shifted photoperiod BPA group, with eight rats in each group. The fixed photoperiod mice received a 12 ∶12 hours light-dark cycle, and the shifted photoperiod mice experienced reversed light-dark cycle once a week. Mice in BPA group were administered a dose of BPA 50 μg/kg body weigh by gavage, while mice in control group were given a equal volume of corn oil, once per day, five days per week for 12 weeks. The body weight of mice was measured during the experiment. After 12 weeks, all mice in each group were sacrificed. Plasma was collected and the levels of biochemical parameters were measured. Liver tissues were separated for examination of lipid deposition using oil red O and hematoxylin-eosin staining, and plasma triglyceride levels were measured. Real-time fluorescence quantitative polymerase chain reaction was used to detect the mRNA relative expression of genes of fat metabolism in liver tissues. RESULTS: At the end of the experiment, the body weights of mice were higher than that before the experiment(all P<0.05), but there was no statistically significant difference in body weights among the four groups(all P>0.05). The levels of plasma glucose, triglyceride and activity of alanine aminotransferase were higher in shifted photoperiod mice than that in the fixed photoperiod mice(all P<0.05). The plasma aspartate transaminase level was higher in BAP group than that in control group(P<0.01). The area of lipid staining in hepatic tissue was larger in the shifted photoperiod control group, fixed photoperiod BPA group and shifted photoperiod BPA group(all P<0.05), and hepatic lipid droplets aggregation was increased in these three groups compared with the fixed photoperiod control group. The mRNA relative expression of acetyl-coenzyme A carboxylase alpha(Acaca) was higher in the fixed photoperiod BPA and shifted photoperiod control groups(all P<0.05), compared with the fixed photoperiod control group. The relative expression of Acaca mRNA was lower in the shifted photoperiod BPA group than that in the fixed photoperiod BPA group(P<0.05). The mRNA relative expression of sterol regulatory element binding protein(Srebp) 1 and Srebp2 were significantly higher in the BPA group than that in the control group(all P<0.05). CONCLUSION: Both the single shifted photoperiod or BPA exposure can increase hepatic lipid deposition in female mice. The mechanism may be related to up-regulation of the mRNA expression of Acaca, Srebp1 and Srebp2. The shifted photoperiod in combination of BPA exposure has an antagonistic effect on the expression of Acaca mRNA in liver tissues of female mice.
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ABSTRACT: The domestic canary (Serinus canaria) has been bred for hundreds of years to improve the quality of its plumage and its song. Reproduction in this species occurs seasonally, stimulated by a gradual increase in day length. Although, the occurrence of seasonal breeding in canaries is well known, whether canary reproduction can be manipulated remains unknown. Our objective was to determine whether the conditions of captivity (photoperiod and temperature) can be adjusted to enable canaries to reproduce outside of their natural breeding season. Thirty days before the natural breeding season, canary pairs were assigned and separated into three different groups: External Control (housed outdoors under ambient conditions), Artificial Control (housed artificially indoors under conditions similar to the external conditions), and Artificial Altered (housed artificially indoors for five months, with the photoperiod gradually manipulated to simulate that of the natural breeding season) groups. The number of clutches laid was greater in the Artificial Control than in External Control; however, more birds hatched in the External Control. In the Artificial Altered group, the beginning of the breeding season was delayed when the same parameters were used. Although, further research is needed, this study presents new data to assist in the development of protocols that entail gradual changes in environmental conditions to try to reduce the impacts of the processes on animal welfare.
RESUMO: O canário doméstico (Serinus canaria) tem sido criado há centenas de anos para melhorar a qualidade da plumagem e do canto. A reprodução nesta espécie é sazonal, sendo estimulada por um aumento gradual da duração do dia. Embora a reprodução sazonal de canários seja bem conhecida, ainda não se sabe se a reprodução dos canários pode ser manipulada. O objetivo foi determinar se as condições em cativeiro (fotoperíodo e temperatura) podem ser ajustadas para permitir que os canários se reproduzam fora de sua estação natural de reprodução. Trinta dias antes da estação natural de reprodução, os pares foram designados e separados em grupos: Controle Externo (alojado em gaiolas sob condições ambientais externas); Controle Artificial (alojado em gaiolas mantidas em condições artificiais semelhantes ao lado externo); e Alterado Artificial (alojado em gaiolas mantidas em condições artificiais constantes por cinco meses, após o fotoperíodo foi gradualmente manipulado para simular o da estação natural de reprodução). O número de posturas foi maior no grupo Controle Artificial do que no Controle Externo; entretanto, mais aves eclodiram no Controle Externo. No grupo Alterado Artificial, o início do período reprodutivo foi atrasado considerando os mesmos parâmetros reprodutivos. Embora mais pesquisas sejam necessárias, este estudo apresenta novos dados para auxiliar no desenvolvimento de protocolos que promovam mudanças graduais das condições ambientais visando reduzir os impactos no bem-estar animal.
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This study aimed to know the daily variation of Astyanax lacustris (Lütken 1875) feeding in a lotic environment. Fish were caught with a net for three days every three hours in the summer to capture ten individuals per hour in a stretch of the Ijuí River, Middle Uruguay River, Brazil. The captured specimens had their stomachs removed and the content analyzed and separated into seven food categories with the aid of stereomicroscope. For the analysis of food items were used the frequency of occurrence methods, volumetric method and applied the Alimentary Index (IAi). Two hundred stomachs were analyzed, of which 95% had food content. The most abundant items were algae and autochthonous insects. Astyanax lacustris feeds throughout the day especially early in the morning (9 hours) and reduces its feeding at night (24 hours and 3 hours). It was also verified variation of AI of different food items throughout the day. It is concluded that A. lacustris feeds throughout the day, especially in the daytime and that throughout the 24 hours it varies its diet due to photoperiod and food availability.
Subject(s)
Animals , Characidae/physiology , Characidae/metabolism , Photoperiod , Animal FeedABSTRACT
The effect of the stay of 6-months-old male Wistar rats under the influence of constant lighting on the dailydynamics of some biochemical parameters was studied. Male Wistar albino rats at the age of 6 months weredivided into 2 groups. The rats from the Group I were housed under a fixed illumination, L:D 14:10 (±180 lux,respectively; 8:00 AM lights on) (unless mentioned otherwise) in a temperature-controlled environment with adlibitum access to tap water and food (rat chow). Animals of Group II were studied under the same experimentalconditions except for the light regime, representing constant light (LL ±180 lux). Both the first and second groupsof animals were kept at the specified light regime for 2 weeks. A number of biochemical parameters of bloodplasma have a reliable daily rhythm, while for other metabolites of an organism a circadian rhythm is not noted.The appearance of the previously absent rhythm of physiological parameters after the application of constantlighting indicates the role of other pacemakers in the metabolism, in addition to illumination. The conductedresearch testifies about the unambiguous modulating influence of constant illumination on the structure of diurnaldynamics of studied biochemical parameters and rectal temperature, and about the initiation of desynchronosisby it
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Abstract Cheirodon interruptus is a ubiquitous small characid that inhabits the Pampean region and commonly used as bait. Its vast market is supplied from the wild population causing a significant environmental impact. In this study, we assess the effect of photoperiod on ovarian maturation in order to evaluate its potential as a tool to manipulate reproduction under artificial conditions. Four treatments in triplicate (light: dark, L: D) were tested: 24L: 0D, 12L: 12D, 0L: 24D and a progressive photoperiod corresponding to the daily photoperiod increments in wild during winter-spring transition, accelerated three times. The experiment was conducted for 45 days. Gonadosomatic index (GSI), oocyte mean diameter, vitellogenic oocyte proportions, plasma estradiol concentrations (E2), condition factor (Kn) and standard length were estimated. Values of mean GSI, oocyte diameter, vitellogenic oocyte proportions and E2 concentration were maximum in the progressive treatment indicating vitellogenesis stimulation. In turn the same parameters were minimum in the 24L: 0D, revealing the vitellogenesis inhibition. This study showed that photoperiodic regime play an important role in the onset of ovarian maturation in C. interruptus.
Resumo Cheirodon interruptus é um pequeno caracídeo amplamente distribuído na região Pampeana e comumente usado como isca. Seu vasto mercado se abastece de populações silvestres causando um impacto ambiental significativo. Neste estudo, investigamos o efeito do fotoperíodo no amadurecimento do ovário para avaliar o potencial deste fator como ferramenta para manipular a reprodução em condições artificiais. Quatro tratamentos foram testados por triplicado (luz: escuro, L: D): 24L: 0D, 12L: 12D, 0L: 24D e um fotoperíodo progressivo que simula as mudanças das horas luz na natureza e na transição de inverno a primavera, acelerado três vezes. O experimento se realizou durante 45 dias. O índice gonadossomático (GSI), o diâmetro médio dos ovócitos, a proporção de ovócitos vitelogênicos, as concentrações plasmáticas de estradiol (E2), o fator de condição (Kn) e o comprimento padrão foram estimados. Os valores médios de GSI, o diâmetro dos ovócitos, as proporções de ovócitos vitelogênicos e a concentração de E2 foram maximizados no fotoperíodo progressivo, indicando estimulação de vitelogênesis. Por outro lado, esses mesmos parâmetros resultaram mínimos no tratamento 24L: 0D, revelando um efeito inibidor da vitelogênesis. Este estudo mostrou que as variações de fotoperíodo exercem um papel importante no início vitelogênesis reprodutiva em C. interruptus .
Subject(s)
Animals , Female , Oocytes/growth & development , Reproduction/physiology , Photoperiod , Characidae/physiology , Seasons , Circadian Rhythm , Estradiol/bloodABSTRACT
Abstract@#Introduction: The purpose of this research is to evaluate the effects of artificial light exposures on the survivals and life traits of adult Aedes aegypti. Methods: This is an experimental research where triplication of each cage filled with a ratio of 20 male : 20 female mosquitoes were exposed under three different light artificial light which are; yellow light, white light and blue light along with three different photoperiod regimes (light:dark) – (14h:10h, 12h:12h and 8h:16h). During this study, life traits data observed were duration of the females to complete a gonotrophic cycle, mean number of days was calculated as well as fecundity rate each cycle was also observed by calculating its number of eggs. Results: In general, gonotrophic cycle of this species is significantly affected by the exposure of the artificial lights where the white light has allowed this species to complete a gonotrophic cycle faster than yellow and blue light with post hoc Tukey’s HSD p = 0.026, however the gonotrophic cycle is found not affected by the different photoperiod regimes. The fecundity of this species is found not to be affected by the artificial light exposure but is affected by the different photoperiod regimes with p = 0.049. Conclusion: In conclusion, artificial light can significantly affect the gonotrophic cycle of Aedes aegypti species while on the other hand, the fecundity of this species is affected by the different photoperiod instead of different artificial light exposure.
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Abstract Timing of activity is a consequence of adaptations to daily and seasonal changes in the environment and examining these patterns is important to better understand the temporal niches of the species. Here we examine temporal activity in the Red-rumped Agouti (Dasyprocta leporina) in two fragments of Atlantic Forest and those factors that influence the circadian rhythm in the study areas. Camera traps were used to gather data in two protected areas (one montane and other coastal) in the state of Espírito Santo, southeastern Brazil. A total of 49 photos were taken in the mountains and 152 in the coastal area. Activity patterns were diurnal and bimodal, and animals were active for 14-15 hours each day. Activity peaked in the morning soon after sunrise and then before and during dusk. Activity patterns were different in the two study areas (W = 6.77, p = 0.034). There was a longer peak in the morning in the coastal area, and a higher peak in the evening in the mountains, where activity starts later and becomes less intense earlier. The difference between activity patterns in the two locations suggests plasticity in agouti behavior. Because the two study areas are at about the same latitude, we suggest that the behavioral plasticity is due to different temperature regimes associated with a local effect of altitude and topography of the terrain on the incidence of solar rays inside the forest. The influence of other factors is also discussed. In addition to a better understanding of the temporal niche of the Red-rumped Agouti, the behavior patterns we describe here can be useful to optimize strategies for D. leporina conservation in southeastern Brazil once the species is more susceptible to poaching at times when animals are most active.
Resumo O horário de atividade reflete adaptações e respostas das espécies às variações diárias e sazonais do ambiente, sendo o entendimento destes padrões importante para uma melhor compreensão do nicho temporal das espécies. Este trabalho objetivou caracterizar o horário de atividade da cutia (Dasyprocta leporina) em dois remanescentes de Mata Atlântica e estabelecer os fatores que podem interferir no ritmo circadiano da espécie considerando peculiaridades das áreas amostradas. Foram analisados dados obtidos a partir de armadilhas fotográficas em duas áreas protegidas, sendo uma na região serrana e outra próximo à costa, ambas no estado do Espírito Santo, sudeste do Brasil. Foram obtidos 49 registros na região serrana e 152 registros na área costeira. A espécie apresentou padrão de atividade diurno e bimodal, mantendo-se ativa por 14-15 horas. Foi detectado um pico de atividade matutino, logo após o nascer do sol, e outro vespertino. O padrão de distribuição diária dos registros foi diferente entre as áreas amostradas (W = 6,766; p = 0,034), ressaltando que o pico de atividade matutino apresentou maior duração na área costeira, enquanto o pico vespertino foi proporcionalmente mais representativo na região serrana, onde as atividades se iniciam mais tarde e se tornam menos intensas mais cedo. Estas diferenças evidenciam a ocorrência de plasticidade comportamental em D. leporina no que se refere ao padrão de atividade local. Entretanto, a diferença entre as áreas estudadas não pode ser atribuída à latitude, uma vez que a distância entre as localidades é de menos de um grau. Sugere-se que a variação do horário de atividade de cutias nas áreas amostradas seja devido a diferenças na temperatura ambiente, associadas a variações locais decorrentes do efeito da altitude e da topografia do terreno na incidência de raios solares no interior da floresta. A influência de outros fatores também é discutida. Além do melhor entendimento do nicho temporal de cutias, os padrões comportamentais descritos no presente estudo podem ser úteis para otimizar estratégias de conservação de D. leporina no sudeste do Brasil considerando que a espécie é mais suscetível à caça quando os animais estão mais ativos.
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RESUMEN Ganoderma lucidum es un hongo macromiceto reconocido por sus propiedades medicinales y su contenido de compuestos bioactivos que incluyen polisacáridos, triterpenoides, proteínas inmunomoduladoras, entre otros, lo que ha generado un incremento notable en su producción. La mayoría de especies de hongos responden y se adaptan a diversas señales ambientales incluida la luz, que favorece su productividad, tanto en calidad como en cantidad al estar estrechamente relacionada con la formación de cuerpos fructíferos. Por tal razón, el objetivo de este estudio fue evaluar la eficiencia biológica (EB) y la tasa de producción (TP) como parámetros de productividad del cultivo sólido de Ganoderma lucidum bajo irradiación de los sustratos con luz emitida por diodos azules (LED) con dos periodos de foto-estímulo de 12 y 24 h durante todas las fases de cultivo para inducir el crecimiento micelial y la formación de los cuerpos fructíferos. Se aplicaron parámetros convencionales para el crecimiento y desarrollo del hongo en las etapas de producción. Para la formulación de los sustratos, se emplearon residuos agroindustriales y materiales lignocelulósicos. El diámetro de los cuerpos fructíferos sometidos a tratamientos con luz azul fue mayor que los exhibidos a luz blanca fluorescente (Testigo). Los resultados muestran que el cultivo de Ganoderma lucidum con exposición a la luz azul es útil para la inducción de cuerpos fructíferos de alta calidad, logrando una disminución del periodo de fermentación en 16 días para el foto-estímulo de 24 h con EB de 28,04% y TP de 0,64.
ABSTRACT Ganoderma lucidum, a renowned fungus for its medicinal properties and content of bioactive compounds include polysaccharides, triterpenoids, immune modulatory proteins, among others; it has generated a significant increase and interest in its production. Most species of fungi respond and adapt to various environmental signal including light, which affects it not only in productivity, but also in quality and quantity to be closely related to the fruiting bodies. Therefore, the objective of this study was evaluating the biological efficiency (EB) and the rate of production (TP) as production parameters of the solid culture of Ganoderma lucidum at under irradiation of the substrate with light emitting diodes blue (LED) with two levels of photo-stimulation constant 12 and 24 h during all steps of culture to induce mycelial growth and the formation of fruiting bodies. Conventional parameters were applied to stimulate the growth and development of the fungus in the stages of production. For the formulation of substrates agro-industrial waste and lignocellulosic materials were used. The diameter of the fruiting bodies under blue light treatments was higher than those exposed to white fluorescent light (control). The results show that the cultivation of Ganoderma lucidum with exposure to blue light is useful for induction of fruiting bodies of high quality, achieving a reduction of the period of fermentation in 16 days for the photo-stimulation of 24 h with EB of 28,04% and TP of 0,64.
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Objective: To increase understanding of the influence of photoperiod variation in patients with bipolar disorders. Methods: We followed a sample of Italian bipolar patients over a period of 24 months, focusing on inpatients. All patients admitted to the Psychiatric Inpatient Unit of San Luigi Gonzaga Hospital in Orbassano (Turin, Italy) between September 1, 2013 and August 31, 2015 were recruited. Sociodemographic and clinical data were collected. Results: Seven hundred and thirty patients were included. The admission rate for bipolar patients was significantly higher during May, June and July, when there was maximum sunlight exposure, although no seasonal pattern was found. Patients with (hypo)manic episodes were admitted more frequently during the spring and during longer photoperiods than those with major depressive episodes. Conclusions: Photoperiod is a key element in bipolar disorder, not only as an environmental factor but also as an important clinical parameter that should be considered during treatment.
Subject(s)
Humans , Male , Female , Adult , Seasons , Sunlight/adverse effects , Bipolar Disorder/etiology , Bipolar Disorder/psychology , Photoperiod , Socioeconomic Factors , Sex Factors , Depressive Disorder, Major , Hospitalization/statistics & numerical data , Italy , Mental Disorders/classification , Mental Disorders/etiology , Mental Disorders/psychologyABSTRACT
RESUMEN Existen numerosos factores que afectan la micropropagación y la microtuberización en papa; entre ellos, las hormonas vegetales y el fotoperiodo. Para estudiar el efecto de estos dos factores en las variedades 'Arbolona negra' (AN) y 'Granola' (G), se cultivaron microesquejes de cada variedad en medio MS líquido con o sin giberelinas (GA) y con 25 g/L de sacarosa e incubados bajo condiciones de luz blanca continua. Para inducir la microtuberización, las vitroplántulas obtenidas fueron sub-cultivadas en medio MS suplementado con 50 g/L sacarosa, tres concentraciones de BA (0, 1 y 5 mg/L) e incubadas bajo diferentes regímenes lumínicos. El pre-tratamiento con GA favoreció el alargamiento del vástago en AN pero no en G. Ambas variedades produjeron el mayor número de microtubérculos en medio MS suplementado con 5 mg/L de BA, bajo condiciones fotoperiódicas, sin la adición previa de GA. El cultivo in vitro de microesquejes de papa en medios de cultivo suplementados con BA y sacarosa, y la incubación bajo condiciones de días cortos permite obtener microtubérculos de papa en condiciones in vitro, en un tiempo más corto que el que podría esperarse en condiciones tradicionales de cultivo.
ABSTRACT Micropropagation and microtuberization in potato plants are both affected by plant hormones and photoperiod. To study the effect of these factors on potato cultivars 'Arbolona negra' (AN) and 'Granola' (G), microcuttings of each cultivar were cultured on MS liquid medium supplemented with sucrose 25 g/L, with or without gibberellins (GA). These microcuttings were incubated under continuous light. In order to induce microtuberization, the obtained vitroplantlets were subcultured on MS medium supplemented with sucrose 50 g/L, three concentrations of BA (0, 1 and 5 mg/L) and incubated under different light patterns. GA pre-treatment induced shoots elongation on AN but not on G cultivar. The highest microtubers production for both cultivars was achieved on MS medium supplemented with BA 5 mg/L under short day light condition without GA pretreatment. The in vitro culture of microcuttings on culture media supplemented with BA and sucrose, incubated under short day conditions, allowed microtubers production in a shorter time lapse.
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Often, in pet birds, any stimulus to lay eggs is unwanted in order to reduce reproductive diseases and disorders. The objectives of this study were: to determine the time necessary to promote ovary involution after an eight hour photoperiod using laying Japanese quails (Coturnix coturnix japonica); to connect the ovarian radiographic measurements with egg production; and to compare these measurements with direct ovary data obtained at necropsy. Birds were separated into three groups: 12h/24d (control group - 12h photoperiod for 24 days), 8h/24d and 8h/36d (8h photoperiod for 24 and 36 days). After euthanasia, all cadavers were x-rayed to measure ovary length and height. Birds were necropsied to measure ovarian length and weight. Results: radiographic ovary length demonstrated strong and positive correlation (r=0.96) with direct ovary length of all three groups; laying quails showed higher ovary height (p=0.025) and length (p=0.009) than non-laying quails; eight hours of artificial light per day promotes ovary length (p=0.025) and weight (p=0.009) reduction. Conclusions: radiography can estimate the ovary measure and indicate posture; an eight hour photoperiod of 24 days is not enough to promote ovarian regression, while the use of reduced photoperiod for 36 days promotes significant ovary involution.(AU)
Em aves de estimação, geralmente se opta pela redução de estímulos para a postura de ovos visando reduzir a ocorrência de doenças e alterações reprodutivas. Os objetivos deste estudo foram: determinar o tempo necessário para a involução ovariana após um fotoperíodo de oito horas de iluminação usando codornas-japonesas (Coturnix coturnix japonica) na fase de postura; relacionar as medidas radiográficas com a postura de ovos; e comparar estas com as medidas diretas obtidas à necropsia. As aves foram divididas em três grupos: 12h/24d (controle - fotoperíodo de 12 horas por 24 dias), 08h/24d e 08h/36d (fotoperíodo de oito horas por 24 e 36 dias). Após a eutanásia, os cadáveres foram radiografados para mensuração do comprimento e da altura do ovário. Foi efetuada a necropsia para aferição das medidas e pesagem dos ovários. Os resultados mostraram que: o comprimento ovariano obtido por meio de imagem radiográfica apresentou forte correlação positiva (r=0,96) com o comprimento direto do ovário das aves dos três grupos; as aves em período de postura apresentaram maiores medidas de altura do ovário (P=0,025) e comprimentos ovarianos (P=0,009) do que as aves fora de postura; a restrição de luminosidade com oito horas diárias de luz artificial promoveu redução do comprimento ovariano (P=0,025) e da massa ovariana (P=0,009). Conclusões: a radiografia pode estimar a medida do ovário e indicar postura; um fotoperíodo de oito horas de luz por 24 dias não é satisfatório para obter uma regressão ovariana, enquanto 36 dias com o fotoperíodo reduzido promovem uma significativa redução ovariana.(AU)
Subject(s)
Animals , Female , Body Weights and Measures/veterinary , Coturnix/anatomy & histology , Ovary/anatomy & histology , Gonads/physiology , Photoperiod , Radiography/veterinaryABSTRACT
Abstract Cheirodon interruptus is a ubiquitous small characid that inhabits the Pampean region and commonly used as bait. Its vast market is supplied from the wild population causing a significant environmental impact. In this study, we assess the effect of photoperiod on ovarian maturation in order to evaluate its potential as a tool to manipulate reproduction under artificial conditions. Four treatments in triplicate (light: dark, L: D) were tested: 24L: 0D, 12L: 12D, 0L: 24D and a progressive photoperiod corresponding to the daily photoperiod increments in wild during winter-spring transition, accelerated three times. The experiment was conducted for 45 days. Gonadosomatic index (GSI), oocyte mean diameter, vitellogenic oocyte proportions, plasma estradiol concentrations (E2), condition factor (Kn) and standard length were estimated. Values of mean GSI, oocyte diameter, vitellogenic oocyte proportions and E2 concentration were maximum in the progressive treatment indicating vitellogenesis stimulation. In turn the same parameters were minimum in the 24L: 0D, revealing the vitellogenesis inhibition. This study showed that photoperiodic regime play an important role in the onset of ovarian maturation in C. interruptus.
Resumo Cheirodon interruptus é um pequeno caracídeo amplamente distribuído na região Pampeana e comumente usado como isca. Seu vasto mercado se abastece de populações silvestres causando um impacto ambiental significativo. Neste estudo, investigamos o efeito do fotoperíodo no amadurecimento do ovário para avaliar o potencial deste fator como ferramenta para manipular a reprodução em condições artificiais. Quatro tratamentos foram testados por triplicado (luz: escuro, L: D): 24L: 0D, 12L: 12D, 0L: 24D e um fotoperíodo progressivo que simula as mudanças das horas luz na natureza e na transição de inverno a primavera, acelerado três vezes. O experimento se realizou durante 45 dias. O índice gonadossomático (GSI), o diâmetro médio dos ovócitos, a proporção de ovócitos vitelogênicos, as concentrações plasmáticas de estradiol (E2), o fator de condição (Kn) e o comprimento padrão foram estimados. Os valores médios de GSI, o diâmetro dos ovócitos, as proporções de ovócitos vitelogênicos e a concentração de E2 foram maximizados no fotoperíodo progressivo, indicando estimulação de vitelogênesis. Por outro lado, esses mesmos parâmetros resultaram mínimos no tratamento 24L: 0D, revelando um efeito inibidor da vitelogênesis. Este estudo mostrou que as variações de fotoperíodo exercem um papel importante no início vitelogênesis reprodutiva em C. interruptus .
ABSTRACT
ABSTRACT: It was possible to evaluate the effect of continuous and intermittent lighting programs with different photophases on the performance and eggs quality of laying hens, applied to the beginning of the laying phase. The authors used 420 Hy-line Brown laying hens with 21 weeks of age, bred on bedding and submitted for six periods of 28 days between the solstice of summer and winter. The three lighting programs were: (PIC) 16 hours of continuos light, intermittent program with initial and final photophases of 15 minutes (PII15) and an intermittent program with initial and final photophases of 30 minutes (PII30). A completely randomized design with ten repetitions of 14 birds was used. The mean values were subjected analysis of variance and analyzed by the Tukey test (5%). The PIC program showed higher feed intake and eggs' mass about the PII15, and the eggs production of birds, in the PIC, was 1.8% greater than the intermittent photoperiods. Programs of light did not change the egg quality. The intermittent programs for semi-heavy laying hens bred on bedding in an open shed, applied at the beginning of the laying phase, reduced the productive performance of the birds without affecting the eggs quality.
RESUMO: Avaliou-se o efeito de programas de iluminação contínuo e intermitentes com diferentes fotofases sobre o desempenho produtivo e a qualidade de ovos de poedeiras aplicados ao início da fase de postura. Foram utilizadas 420 poedeiras da linhagem Hy line Brown com 21 semanas de idade, criadas sobre cama, submetidas durante seis períodos de 28 dias, entre o solstício de verão e de inverno, a três programas de iluminação: contínuo (PIC) de 16h de luz; programa intermitente com fotofases inicial e final de 15min (PII15); e programa intermitente com fotofases inicial e final de 30min (PII30). Utilizou-se um delineamento inteiramente casualisado, com dez repetições de 14 aves. Os resultados das médias foram submetidos à análise de variância e analisadas pelo teste de Tukey (5%). O programa PIC apresentou maior consumo de ração e massa de ovos em relação ao PII15, a produção de ovos das aves no PIC foi 1,8% superior aos fotoperíodos intermitentes. Os programas de luz não alteraram a qualidade de ovo. Programas intermitentes para poedeiras semipesadas, criadas sobre cama em galpão aberto, aplicados no início da fase de postura reduzem o desempenho produtivo das aves sem afetar a qualidade de ovos.
ABSTRACT
A incidência luminosa pode induzir diversos efeitos sobre o crescimento, alimentação, desenvolvimento e reprodução de peixes. O fotoperíodo é sinal principal para maior influência sobre o ritmo circadiano dos peixes e pode afetar o ganho de peso, a ingestão de alimento e a utilização de energia. O objetivo deste trabalho foi avaliar os efeitos de diferentes regimes de fotoperíodo no crescimento, consumo alimentar e qualidade da carcaça de tilápias invertidas, em um sistema fechado. Foram utilizados 150 alevinos de tilápias invertidas, provenientes da estação de piscicultura. Os peixes foram acondicionados e distribuídos em 15 aquários com a capacidade de 65 litros cada um, em delineamento inteiramente ao acaso, com três tratamentos e cinco repetições. Os tratamentos diferenciarão nas simulações dos fotoperíodos emerais (horas de luz) que durarão T1= 24 horas de escuro, T2= 12 horas de escuro e 12 horas de Luz, T3= 24 horas de luz. Cada peixe foi considerado uma unidade experimental. Não houve diferença significativa para desempenho, mas houve diferença para Índice gonadossomático (IGS). Conclui-se que o fotoperíodo (12L:12E) promove melhor índice gonadossomático em tilápia. Para melhor qualidade de carcaça e desempenho produtivo sugere o fotoperíodo (24L:0E).
The light incidence can induce different effects on growth, feeding and development and reproduction of fish. The photoperiod is the main signal for greater influence on the circadian rhythm of the fish and can affect weight gain, feed intake and energy use. This study aimed to demonstrate the effects of different photoperiodic regimes on growth, feed intake and carcass tilapia quality reversed in a closed system. 150 were used fry reversed tilapia, from fish farming station. The fish were packed and distributed in 15 tanks with a capacity of 65 liters each, in a completely randomized design with three treatments and five repetitions. Treatments differentiate in the simulations of emerais photoperiod (light hours) that will last T1 = 24 hours dark, T2 = 12 hours of darkness and 12 hours light, T3 = 24 hours of light. Each fish was considered an experimental unit. There was no significant difference in performance, but there were differences for IGS. I conclude that the photoperiod (12L: 12D) promotes better GSI in tilapia. To better carcass quality and growth performance suggests the photoperiod (24L: 0D).
La incidencia de luz puede inducir diversos efectos sobre el crecimiento, alimentación, desarrollo y reproducción de peces. El fotoperiodo es la señal principal de una mayor influencia en el ritmo circadiano de los peces y puede afectar la ganancia de peso, la ingestión de alimento y el consumo de energía. El objetivo de esta investigación ha sido demostrar los efectos de diferentes regímenes de fotoperiodo sobre el crecimiento, consumo alimentar y calidad de caparazón de tilapias invertidas, en un sistema cerrado. Se utilizaron 150 alevines de tilapias invertidas, provenientes de la estación de piscicultura. Los peces fueron acondicionados y distribuidos en 15 tanques con una capacidad de 65 litros cada uno, en un diseño completamente al azar, con tres tratamientos y cinco repeticiones. Los tratamientos se diferencian en las simulaciones de fotoperiodos emerales (horas de luz) que durarán T1 = 24 horas de oscuridad, T2 = 12 horas de oscuridad y 12 horas de luz, T3 = 24 horas de luz. Cada pez fue considerado una unidad experimental. No hubo diferencia significativa en el rendimiento, pero hubo diferencia para el Índice Gonadosomático (IGS). Se concluye que el fotoperiodo (12L: 12D) promueve mejor GSI en tilapia. Para mejor calidad de caparazón y rendimiento de la producción se sugiere fotoperiodo (24L: 0E).
Subject(s)
Animals , Eating , Meat/analysis , Meat/toxicity , Photoperiod , TilapiaABSTRACT
Bats of the Phyllostomidae family exhibit different reproductive patterns in Neotropical regions and the strategy adopted depends on the regional climate. Here we studied the reproductive biology of Artibeus fimbriatus at the southern limit of their distribution in Brazil. This region has no rainy season, and the climate is characterized by high temperatures and variable photoperiods. We examined 129 A. fimbriatus females over several months, and used histological procedures where necessary in order to determine whether bats were pregnant. Females exhibited a long reproductive period and were pregnant from June until February. The reproduction events were found to be dependent on the photoperiod, but independent of annual accumulated precipitation. Our results show that at the southern limit of their distribution, A. fimbriatus exhibit seasonal-dependent reproductive patterns, with parturition events occurring during spring and summer, in which the days are longer and temperature is warmer.
Os morcegos Phyllostomidae apresentam diferentes padrões reprodutivos no Neotropico e a estratégia adotada depende do clima regional. Neste trabalho nós estudamos a biologia reprodutiva de A. fimbriatus no Brasil, na região que determina o limite sul de sua distribuição geográfica, onde não há estação chuvosa e o clima é caracterizado por variações na temperatura e fotoperíodo. Nós examinamos 129 fêmeas de A. fimbriatus e utilizamos procedimentos histológicos, quando necessário, para classificar as fêmeas como prenhe ao longo dos meses. As fêmeas exibem um longo período reprodutivo e estão grávidas de junho até fevereiro. Nossos resultados mostram que as fêmeas de A. fimbriatus apresentam uma estratégia reprodutiva que é dependente da sazonalidade com os nascimentos ocorrendo quando os dias são mais longos e a temperatura é maior (primavera e verão), no limite sul de sua distribuição geográfica.
ABSTRACT
A presente pesquisa analisou o efeito da iluminação constante sobre a estrutura placentária de ratas, abordando parâmetros morfológicos, morfométricos e histoquímicos. Vinte ratas albinas foram submetidas aos seguintes tratamentos: 12hL/12hE por 60 dias, e acasaladas em seguida (GI); ausência de luz por 60 dias, e acasaladas em seguida (GII); iluminação constante por 60 dias, e acasaladas em seguida (GIII); iluminação constante por 60 dias, acasaladas em seguida e tratadas com melatonina (GIV). O estímulo luminoso foi em torno de 400 lux. A melatonina foi administrada na água (400mg/mL de etanol). Os resultados mostraram que histologicamente o GII apresentou vacuolização das células do trofospongio. Morfometricamente, o GIII apresentou camada do labirinto com redução no número de trofoblastos sinciciais e maior vascularização materno-fetal, hiperplasia e hipertrofia das células trofoblásticas gigantes, uma maior média da área total do disco placentário; porém, na camada de trofospongio, as células trofoblásticas e trofoblastos sinciciais não diferiram nos grupos experimentais. As placentas do GIV foram semelhantes às do GI. Histoquimicamente não houve alterações nas fibras colágenas, elásticas, reticulares e glicosaminoglicanas ácidas. Em conclusão, a iluminação constante promove alterações morfológicas e morfométricas na placenta de ratas, podendo acarretar redução funcional e restrições ao crescimento fetal. Essas alterações são abolidas pela reposição de melatonina.
This study examined the effect of constant illumination on the placental structure of rats, addressing morphological, morphometric and immunohistochemical parameters. 20 albino rats were subjected to the following treatments: GI-12hL/12hE for 60 days and then mated; GII- dark for 60 days and then mated; GIII- constant illumination for 60 days and then mated and GIV- constant light for 60 days, mated and then treated with melatonin. The light stimulus was around 400 lux. Melatonin was administered in water (400 mg / ml ethanol). The results showed that GII had histologically trofospongio vacuolization of cells. Morphometrically, GIII presented a labyrinth layer reduction in the number of syncytial trophoblasts and greater maternal-fetal vasculature, hyperplasia and hypertrophy of trophoblast giant cells, a higher average of the total area of the placenta disk, but in the trofospongio layer, the trophoblast cells and syncytial trophoblasts did not differ between experimental groups. The placentas in GIV were similar to GI. Histochemically there were no changes in the collagen and elastic fibers, reticular and acidic glycosaminoglycans. In conclusion, the constant lighting promotes morphological and morphometric changes in the placenta in rats and may lead to functional reduction and restrictions on fetal growth. These changes are abolished by the melatonin replacement.
Subject(s)
Animals , Female , Pregnancy , Rats , Lighting/methods , Placenta/anatomy & histology , Fetal Development , Melatonin/analysis , PhotoperiodABSTRACT
In the present study, the effects of different photoperiods on stress, immunity, and hematological parameters in ICR mice were evaluated. Fifty male ICR mice 7 weeks old (body weight, 27.3 +/- 2.5 g) were divided into five groups: DP-0 (0/24-h light/dark cycle), DP-6 (6/18-h light/dark cycle), DP-12 (12/12-h light/dark cycle), DP-18 (18/ 6-h light/dark cycle), and DP-24 (24/0-h light/dark cycle). During the experimental period, no significant differences in body weight or feed intake were observed between the groups. Hematological analysis revealed that white blood cell, red blood cell, and hemoglobin values for the DP-0 group were significantly different compared to those of the other groups. After 28 days, no significant difference in serum cortisol concentration was observed among the groups, but serum cortisol levels increased in a light exposure-dependent manner. Total serum immunoglobulin G (IgG) concentrations of the DP-0 and PD-6 groups were significantly increased compared to those of the other groups (P < 0.05), and serum total IgG levels decreased in a light exposure-dependent manner. Results of the present study indicated that various photoperiods affect hematological parameters and total serum IgG levels in ICR mice while having no significant effects on body weight, feed intake, or cortisol levels.
Subject(s)
Animals , Humans , Male , Mice , Body Weight , Erythrocytes , Hydrocortisone , Immunoglobulin G , Leukocytes , Mice, Inbred ICR , PhotoperiodABSTRACT
The cyanobacterium Oscillatoria agardhii was isolated from the fresh water Mawatha lake, Jaipur and was grown in Zarrouk's medium at 25 ± 2°C, illuminated with white fluorescent light at the intensity of 2 500 lux with 12:12 h light and dark photoperiod. The effects of photoperiod and temperature on the growth and protein expression by Oscillatoria agardhii were studied under different controlled culture conditions (ALR, ALC, CLR, CLC, and NDL), measuring optical density, cell count and dry weight. Protein content was measured quantitatively by Bradford assay and qualitatively by SDS-PAGE. The densitometric analysis was also carried out for the measurement of the expression level of different proteins/peptides under different culture conditions. Maximum growth and protein content were observed in ALR condition while minimum was in the CLC. Alternate light and dark periods proved efficient as contrasting banding patterns were observed with many new unique polypeptides such as 32, 36.3, 47.9, 60.8, and 67.0 kDa, whereas, expressions of three polypeptides of 57.2, 110.1, and 117.3 kDa were inhibited in constant light cultures.