The responsive characteristics of phytochrome genes to photoperiod, abiotic stresses and identification of their key natural variation sites in foxtail millet (Setaria italica L.) / 生物工程学报

The responsive patterns of phytochrome gene family members to photoperiod and abiotic stresses were comparatively analyzed and the favorable natural variation sites of these genes were identified. This would help understand the mechanism of phytochrome gene family in photoperiod-regulated growth and development and abiotic stress response. In addition, it may facilitate the molecular marker assisted selection of key traits in foxtail millet. In this study, we used RT-PCR to clone three phytochrome genes SiPHYA, SiPHYB and SiPHYC from ultra-late maturity millet landrace variety 'Maosu'. After primary bioinformatics analysis, we studied the photoperiod control mode and the characteristics of these genes in responding to five abiotic stresses including polyethylene glycol (PEG)-simulated drought, natural drought, abscisic acid (ABA), high temperature and NaCl by fluorescence quantitative PCR. Finally, we detected the mutation sites of the three genes among 160 foxtail millet materials and performed haplotype analysis to determine the genes' functional effect. We found that the cloned cDNA sequences of gene SiPHYA, SiPHYB and SiPHYC were 3 981, 3 953 and 3 764 bp respectively, which contained complete coding regions. Gene SiPHYB and SiPHYC showed closer evolutionary relationship. Photoperiod regulated all of the three genes, but showed more profound effects on diurnal expression pattern of SiPHYB, SiPHYC than that of SiPHYA. Under short-day, when near heading, the expression levels of SiPHYA and SiPHYB were significantly lower than that under long-day, indicating their roles in suppressing heading of foxtail millet under long-day. SiPHYB and SiPHYC were responsive to PEG-simulated drought, natural drought, ABA and high temperature stresses together. SiPHYA and SiPHYB responded differently to salt stress, whereas SiPHYC did not respond to salt stress. Re-sequencing of 160 foxtail millet materials revealed that SiPHYB was highly conservative. Two missense mutations of SiPHYA, such as single nucleotide polymorphism (SNP) 7 034 522C→T and SNP7 036 657G→C, led to delaying heading and increasing plant height. One missense mutation of SiPHYC, such as SNP5 414 823G→T, led to shortening heading under short-day and delaying heading under long-day, as well as increasing plant height and panicle length regardless of photo-thermal conditions. Photoperiod showed different regulatory effects on SiPHYA, SiPHYB and SiPHYC. SiPHYB and SiPHYC jointly responded to various abiotic stresses except for the salt stress. Compared with the reference genotype, mutation genotypes of SiPHYA and SiPHYC delayed heading and increased plant height and panicle length.

Daily variation feeding of Astyanax lacustris (Lütken 1875) in a subtropical river

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.

Expression and function analysis of FaCO gene in Festuca arundinacea / 生物工程学报

Photoperiod plays an important role in transformation from vegetative growth to reproductive growth in plants. CONSTANS (CO), as a unique gene in the photoperiod pathway, responds to changes of day length to initiate flowering in the plant. In this study, the expression level of FaCONSTANS (FaCO) gene under long-day, short-day, continuous light and continuous darkness conditions was analyzed by real-time quantitative PCR. We constructed the over-expression vector p1300-FaCO and infected into Arabidopsis thaliana by Agrobacterium-mediated method. We constructed the silencing vector p1300-FaCO-RNAi and infected into Festuca arundinacea by Agrobacterium-mediated method. The expression of FaCO gene was regulated by photoperiod. The over-expression of FaCO promoted flowering in wild type of Arabidopsis thaliana under long day condition and rescued the late flowering phenotype in co-2 mutant of Arabidopsis thaliana. Silencing FaCO gene in Festuca arundinacea by RNAi showed late-flowering phenotype or always kept in the vegetative growth stage. Our understanding the function of FaCO in flowering regulation will help further understand biological function of this gene in Festuca arundinacea.

Photoperiodic effects in blood glucose, cortisol, hematological parameters and reproductive indexes of gift lineage reversed male tilapia / Efeito do fotoperiódo na glicose sanguínea, cortisol, parâmetros hematológicos e índices reprodutivos da linhagem gift tilapia masculina

The objective of this study was to evaluate the influence of the photoperiod on the physiological, hematological and reproductive parameters of tilapia males of the GIFT lineage. The treatments differed in the simulations of emeral photoperiods T1 = 0L: 24E T2 = 24L: 0E, T3 = 12L: 12E. Each aquarium was considered an experimental unit. In the present study, tilapia males under different photoperiods did not present significant differences in gonad weight and gonadosomatic index. At the end of the experiment, there were also no significant differences in hepatosomatic indexes (IHS) of Tilapia males under different treatments. In the present experiment, it was observed that the 0L: 24E treatment obtained a shorter testicular length in relation to the other treatments. In addition, the Tilapia submitted to 24L: 0E presented significant difference for the glucose levels, and did not present significant difference for cortisol levels and survival rate compared withthe other treatments. There were no statistical differences for hematological values. Exposure to different light regimes has shown that for GIFT tilapia, the photoperiod that promotes better reproductive index and well-being conditions is the photoperiod (12L: 12E).

O objetivo deste estudo foi avaliar a influência do fotoperíodo nos parâmetros fisiológicos, hematológicos e reprodutivos de machos de tilápia da linhagem GIFT. Os tratamentos diferiram nas simulações dos fotoperíodos emeral T1 = 0L: 24E T2 = 24L: 0E, T3 = 12L: 12E. Cada aquário foi considerado uma unidade experimental. No presente estudo, os machos de tilápia sob diferentes fotoperíodos não apresentaram diferenças significativas no peso gonadal e no índice gonadossomático. Ao final do experimento, também não houve diferenças significativas nos índices hepatossomáticos (IHS) dos machos de tilápias sob diferentes tratamentos. No presente experimento, observou-se que o tratamento 0L: 24E obteve menor comprimento testicular em relação aos demais tratamentos. Além disso, a tilápia submetida a 24L: 0E apresentou diferença significativa para os níveis de glicose, e não apresentou diferença significativa para os níveis de cortisol e sobrevivência em comparação com os demais tratamentos. Não houve diferenças estatísticas para valores hematológicos. A exposição a diferentes regimes de luz mostrou que, para a tilápia GIFT, o fotoperíodo que promove melhor índice reprodutivo e condições de bem-estar é o fotoperíodo (12L: 12E).

Effect of photoperiod on ovarian maturation in Cheirodon interruptus (Teleostei: Characidae) / Efeito do fotoperíodo na maturação dos ovários em Cheirodon interruptus (Teleostei: Characidae)

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 .

Biology of Corythucha gossypii Fabricius, 1794 (Hemiptera: Tingidae) in Ricinus communis at different temperatures and thermal requirements / Biologia de Corythucha gossypii Fabricius, 1794 (Hemiptera: Tingidae) em Ricinus communis em diferentes temperaturas e exigências térmicas

Abstract We studied the biology of Corythucha gossypii in Ricinus communis under different temperatures in climatic chambers adjusted at 20, 23, 25, and 28 °C, 60 ± 10% relative humidity, and a 12-h photoperiod. The development period and viability of eggs, the development period and survival rate of nymphs, and egg-adult cycle of C. gossypii as well as the adult longevity and fecundity were estimated. The thermal requirements (K) and temperature-base (Tb) were estimated for each of the immature stages and for the eggs-adults period. The duration of the eggs and nymphs phases and the egg-adult cycle of the C. gossypii on castor bean leaves at 20-28 °C were 7.6-17 days, 10.2-27.5 days, and 16.9-44.5 days, respectively. The lower temperature inhibited the oviposition of C. gossypii, whereas the higher temperatures were most favorable for its development. The municipalities of the Bahia state of Brumado, Irecê, Itaberaba, Jacobina, and Senhor do Bonfim were estimated to have a high potential for the population growth of C. gossypii. However, a greater number of generations per year of C. gossypii were observed in the municipalities of Brumado and Itaberaba.

Resumo Estudamos a biologia de Corythucha gossypii em Ricinus communis sob diferentes temperaturas em câmaras climatizadas ajustadas as temperaturas de 20, 23, 25 e 28 °C, umidade relativa de 60 ± 10% e fotoperíodo de 12 horas. O período de desenvolvimento e a viabilidade dos ovos, o período de desenvolvimento e a taxa de sobrevivência de ninfas e do ciclo de ovo-adulto de C. gossypii, bem como a longevidade dos adultos e fecundidade foram estimados. As exigências térmicas (K) e as temperaturas-bases (Tb) foram estimadas para cada um dos estádios imaturos e para o ciclo de ovo-adulto. A duração das fases de ovos e ninfas e do ciclo de ovo a adulto de C. gossypii em folhas de mamona a 20-28 °C foram de 7,6-17 dias, 10,2-27,5 dias e 16,9-44,5 dias, respectivamente. A temperatura mais baixa inibiu a oviposição de C. gossypii , enquanto as temperaturas mais altas foram favoráveis ao seu desenvolvimento. Os municípios do estado da Bahia de Brumado, Irecê, Itaberaba, Jacobina e Senhor do Bonfim foram estimados para ter um alto potencial para o crescimento populacional de C. gossypii. No entanto, o maior número de gerações por ano de C. gossypii foi observado nos municípios de Brumado e Itaberaba.

Effects of light-dark cycle on the spatial distribution and feeding activity of fish larvae of two co-occurring species (Pisces: Hypophthalmidae and Sciaenidae) in a Neotropical floodplain lake / Efeitos do ciclo claro-escuro na distribuição espacial e na atividade alimentar de larvas de peixes de duas espécies coexistentes (Pisces: Hypophthalmidae e Sciaenidae) em uma lagoa de planície de inundação Neotropical

Abstract Most studies on mechanisms regulating fish larvae processes have focused on assessing the isolated effects of food distribution and feeding behavior. However, in natural ecosystems, fish larvae may strongly interact with zooplankton organisms in an array of complex, direct and indirect interdependencies. This study analyzed the spatial distribution, diet and feeding behavior of early stages of Hypophthalmus edentatus and Plagioscion squamosissimus, two fish species co-occurring in an isolated floodplain lake, during the light-dark cycle. Larvae fed more actively during dark periods (dusk and night) when they migrated toward the surface of the lake, and remained on the bottom and fed less during light periods (day and dawn). Cladocerans represented the most frequent prey in the diet of H. edentatus larvae. In turn, P. squamosissimus larvae initially preferred cladocerans and, as they developed, included calanoid copepods in the diet. Significant differences were detected in the frequencies of food items consumed during larval development, which could be related to a better ability of the most developed stages to explore the environment in search of other prey.

Resumo A maioria dos estudos de mecanismos que regulam os processos de larvas de peixes se concentra na avaliação dos efeitos isolados da distribuição do alimento e do comportamento alimentar. No entanto, em ecossistemas naturais, as larvas de peixes podem interagir fortemente com os organismos do zooplâncton em uma série de interdependências complexas, diretas e indiretas. Este estudo analisou a distribuição espacial, dieta e comportamento alimentar dos estágios iniciais de vida de Hypophthalmus edentatus e Plagioscion squamosissimus, duas espécies de peixes coexistentes em uma lagoa isolada de planície de inundação, durante o ciclo claro-escuro. As larvas se alimentaram mais ativamente durante os períodos escuros (crepúsculo e noite) quando ascenderam em direção à superfície da lagoa, enquanto durante os períodos luminosos (dia e amanhecer) permaneceram no fundo e pouco se alimentaram. Os cladóceros foram as presas mais frequentes na dieta de larvas de H. edentatus. Por sua vez, larvas de P. squamosissimus inicialmente preferiram cladóceros, e a medida que se desenvolveram incluíram copépodes calanóides na dieta. Diferenças significativas foram detectadas nas frequências dos itens alimentares consumidos durante o desenvolvimento larval, o que poderia estar relacionado a uma melhor capacidade dos estágios mais desenvolvidos em explorar o ambiente na busca por outras presas.

Phenology of Guarea macrophylla Vahl (Meliaceae) in subtropical riparian forest in southern Brazil / Fenologia de Guarea macrophylla Vahl (Meliaceae) em mata ciliar subtropical no sul do Brasil

Abstract Climate is one of the main factors that affect plant behavior. The phenology of Guarea macrophylla Vahl, which is a small tree used for reforestation of degraded areas, was monitored for 18 months in a riparian forest at the Schmidt Stream, Campo Bom, in the state of Rio Grande do Sul, southern Brazil. Vegetative (leaf fall and leaf flushing) and reproductive events were observed, with the latter divided into flowering (flower buds and anthesis) and fruiting (unripe, ripening and ripe fruit). Phenological events were related to temperature, photoperiod and precipitation and their seasonality was verified by circular statistical analysis. Vegetative phenophases were continuous; they were not related to climate factors and presented low intensity, emphasizing the perennial aspect of the species. Flowering occurred during spring and summer. Both flower buds and anthesis were related to temperature and photoperiod. Fruiting was constant and went through all stages of development. Unripe fruits developed during the months with the lowest photoperiod and ripen more intensely in winter, on colder days. Ripe fruit became available for dispersal in spring, in times of longer photoperiod and higher temperatures. Except for leaf fall, all other phenological events showed seasonality in their manifestation. The one-month difference between the onsets of the flowering phases observed in this study indicated that local climate changes induced the early occurrence of this phenophase.

Resumo O clima é um dos principais fatores que condicionam o comportamento das plantas. A fenologia de Guarea macrophylla Vahl, arvoreta utilizada no reflorestamento de áreas degradadas, foi acompanhada durante 18 meses, em mata ciliar do arroio Schmidt, Campo Bom, RS, Brasil. Foram observados os eventos vegetativos (queda foliar e brotamento) e reprodutivos, separados em floração (botão floral e antese) e frutificação (frutos imaturos, maturando e maduros). Os eventos fenológicos foram relacionados à temperatura, ao fotoperíodo e à precipitação e a sua sazonalidade foi verificada por meio da análise estatística circular. As fenofases vegetativas foram contínuas, não se relacionaram com os fatores climáticos e apresentaram baixa intensidade, ressaltando a característica perene da espécie. A floração ocorreu durante a primavera e o verão e tanto botão floral quanto antese relacionaram-se com temperatura e fotoperíodo. A frutificação foi constante e passou por todos os estádios de desenvolvimento. Os frutos imaturos desenvolveram-se em meses com o menor fotoperíodo e maturaram mais intensamente no inverno, em dias de menor temperatura. Os frutos maduros tornaram-se disponíveis para os dispersores na primavera, em períodos com maior fotoperíodo e temperatura. Com exceção da queda foliar, todos os outros eventos fenológicos apresentaram sazonalidade em sua manifestação. O adiantamento de um mês entre as florações observadas no presente estudo indicou que as alterações climáticas locais de temperatura induziram a ocorrência antecipada dessa fenofase.

Bipolar disorders: is there an influence of seasonality or photoperiod?

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.

The influence of a light and dark cycle on the egg laying activity of Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae)

BACKGROUND The epidemiological importance of the mosquito Aedes aegypti as a vector of multiple human pathogens has generated a growing number of studies on the physiology and behaviour of its blood-feeding females. The activity of oviposition is one of the critical elements contributing to the expansion of Ae. aegypti's populations. Although there is a vast literature about oviposition behaviour, significant specific knowledge about egg viability and female fertility under light and dark conditions is still lacking. OBJECTIVES We studied, in controlled laboratory conditions, the effect that light and dark cycles have on the efficiency of oviposition by Ae. aegypti females. METHODS Physiological assays were performed using synchronised eggs obtained from forced egg laying. The number and viability of eggs was analysed under three different light/dark regimes: LD12:12 (12 h of light and 12 h of dark), DD (constant darkness) and LL (constant light). FINDINGS and CONCLUSIONS Our results show that females prefer to lay their eggs in dark conditions, but maximising the number and viability of eggs requires the occurrence of a light/dark cycle. Ongoing research on this theme has the potential of contributing to the proposition of new strategies for control based on the failure of egg laying and hatching.

Development of the "Third-Generation" Hybrid Rice in China / 基因组蛋白质组与生物信息学报·英文版

Rice is a major cereal crop for China. The development of the "three-line" hybrid rice system based on cytoplasmic male sterility in the 1970s (first-generation) and the "two-line" hybrid rice system based on photoperiod- and thermo-sensitive genic male-sterile lines (second-generation) in the 1980s has contributed significantly to rice yield increase and food security in China. Here we describe the development and implementation of the "third-generation" hybrid rice breeding system that is based on a transgenic approach to propagate and utilize stable recessive nuclear male sterile lines, and as such, the male sterile line and hybrid rice produced using such a system is non-transgenic. Such a system should overcome the intrinsic problems of the "first-generation" and "second-generation" hybrid rice systems and hold great promise to further boost production of hybrid rice and other crops.

Ovarian radiographic and direct measurements of Japanese Quail ( Coturnix coturnix japonica ) submitted to light restriction / Medidas ovarianas radiográficas e diretas de codorna-japonesa (Coturnix coturnix japonica) submetida à restrição luminosa

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)

Environmental drivers on leaf phenology of ironstone outcrops species under seasonal climate

ABSTRACT Banded iron formations (BIF) have a particular vegetation type and provide a good model system for testing theories related to leaf phenology, due to unique stressful environmental conditions. As a consequence of the stressful conditions of BIF environment, we hypothesize that most species would retain at least some significant canopy cover, even at the end of the dry season, independently of growth form - trees, shrubs, and sub-shrubs. Considering the strong seasonality, we also hypothesize that photoperiod and rainfall act as triggers for leaf fall and leaf flushing in these environments. The majority of the fifteen studied species had a semi-deciduous behavior and shed their leaves mainly during the dry season, with a recovery at the end of this season. In general, leaf flushing increased around the spring equinox (end of the dry season and start of the rainy season). A trade-off between leaf loss and leaf maintenance is expected in a community in which most plants are naturally selected to be semi-deciduous. Our results suggest photoperiod as a dominant factor in predicting leaf phenology.

Physical characterization of Rhipsalis (Cactaceae) fruits and seeds germination in different temperatures and light regimes / Caracterização física de frutos de Rhipsalis (Cactaceae) e germinação de sementes em diferentes regimes de temperatura e luz

Abstract The germination characteristics of the native cactus species are poorly known, being the temperature and the light the factors that the most interferes in that process. Thus, the objective of the present work was to characterize the fruits and evaluate the influence of the temperature and the light in the seed germination of Rhipsalis floccosa, Rhipsalis pilocarpa and Rhipsalis teres. The tested constant temperatures were 15, 20, 25, 30 and 35 °C and the alternate of 20-30 °C and 25-35 °C in a photoperiod of 10 hours, and with determination of the most appropriate temperature, the germination was tested in light absence. The germination percentage, the index of germination speed and medium time of germination were evaluated. For R. floccosa, the highest germination percentage was at 20 °C. For R. pilocarpa and R. teres, the highest germination percentages occurred in 15 °C and 20 °C. There was correlation to germination percentage between the three species, indicating that they had similar germination behavior. Total absence of germination was verified for the three species in condition of light absence. In conclusion, the temperature of 20 °C is the most suitable for the seed germination of R. floccosa. For the species R. pilocarpa and R. teres, the temperatures of 15 and 20 °C are the most suitable.

Resumo Existem poucos estudos sobre características germinativas de espécies de cactos nativos, sendo a temperatura e a luz, os fatores que mais interferem nesse processo. Assim, objetivou-se caracterizar os frutos e avaliar a influência da temperatura e luminosidade na germinação de sementes de Rhipsalis floccosa, Rhipsalis pilocarpa and Rhipsalis teres. Testou-se temperaturas constantes de 15, 20, 25, 30 e 35 °C e alternadas de 20-30 °C e 25-35 °C com fotoperíodo de 10 horas, e com a determinação da temperatura mais adequada, testou-se a germinação na ausência de luz. A porcentagem de germinação, o índice de velocidade de germinação e o tempo médio de germinação foram avaliados. Para R. floccosa, a maior porcentagem de germinação foi obtida a 20 °C. Para R. pilocarpa e R. teres, as maiores porcentagens de germinação ocorreram a 15 °C e 20 °C. Verificou-se correlação entre as três espécies para a porcentagem de germinação, indicando comportamento semelhante entre essas. Na ausência de luz não ocorreu a germinação das sementes das espécies estudas. Em conclusão, a temperatura de 20 °C é a mais indicada para a germinação de sementes de R. floccosa. Para as espécies R. pilocarpa e R. teres, as temperaturas de 15 e 20 °C são as mais indicadas.

Efeito do fotoperíodo no crescimento, consumo alimentar e qualidade da carcaça de tilápias invertidas / Photoperiod effect on growth, feed intake and carcass quality reversed tilapia / Efecto de fotoperiodo en el crecimiento, consumo alimentar y calidad de caparazón de tilapias invertidas

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).

Rodent Models of Diet-induced Obesity

The prevalence of obesity is rapidly increasing worldwide, and its complications such as type 2 diabetes and cardiovascular disease are also increasing. To avoid long-term damage caused by obesity and its complications, we must develop preventive measures and therapeutic agents based on the pathophysiology of human obesity. However, genetically-modified rodents are mainly used for obesity research. This type of animal model is not very suitable for the study of human obesity because environmental factors such as excessive food intake and sedentary lifestyle are major causes of the recent explosion in human obesity. Therefore, diet-induced obesity rodent models are more appropriate for research in human obesity. Type of diet, animal species, duration of food intake, age, and sex can play a role in determining body weight and levels of glucose, insulin, triglycerides, and leptin. Animal housing conditions such as the number of animals per cage, ambient temperature, and length of the light-dark cycle also influence body weight and metabolic parameters. As a result, many influencing factors should be considered in the development of an appropriate diet-induced obesity rodent model for successful obesity research.

Delay in Normalization of Disrupted Sleep-Wake Cycle in Mice as a Bipolar Disorder-Prone Animal Model (Bipolar Disorder-Prone Animal Model) / 신경정신의학

OBJECTIVES: This study was designed to test the hypothesis that delayed recovery from disrupted circadian rhythm is associated with both manic and depressive episodes in bipolar disorder. METHODS: Twenty-two male mice (age of five weeks, weight 28–30 gm) underwent three days of light-dark cycle disruption and 10 days of recovery phase. Sleep and wake state were checked every five minutes during the entire experimental period. After recovery phase, quinpirole (0.5 mg/kg, s.c.) was injected into the mice and open field locomotor activities were checked. Five days after the open field test, immobility time during the last 4 min in 6 min of forced swimming test was measured. Animals which recovered sleep-wake cycle within six days after light-dark cycle disruption were assigned to the early recovery group (n=14), and those that failed to recover in six days were assigned to the delayed recovery group (n=8). The locomotor activities and the immobility times of the two groups were compared by Mann-Whiney U test at two-tailed significance level of 0.05. RESULTS: The locomotor activities of the delayed recovery group were higher (mean rank=16.19) than those of the early recovery group (mean rank=8.82, U=18.5, p=0.008). The immobility times did not differ by recovery time (U=32.0 p=0.110). CONCLUSION: The results suggest that delayed recovery from circadian rhythm disruption raises the risk of manic symptoms rather than depressive symptoms.

Thermal preferences and limits of Triatoma brasiliensis in its natural environment - Field observations while host searching

The goal of this work was to explore the thermal relationship between foraging Triatoma brasiliensis and its natural habitat during the hottest season in the state of Ceará, Brazil. The thermal profiles were determined using infrared analysis. Although the daily temperature of rock surfaces varied in a wide range, T. brasiliensisselected to walk through areas with temperatures between 31.7-40.5ºC. The temperature of T. brasiliensisbody surface ranged from 32.8-34.4ºC, being higher in legs than the abdomen. A strong relationship was found between the temperature of the insect and the temperature of rock crevices where they were hidden (r: 0.96, p < 0.05). The species was active at full sunlight being a clear example of how the light-dark rhythm may be altered, even under predation risk. Our results strongly suggest a thermal borderline for T. brasiliensisforaging activity near 40ºC. The simultaneous determination of insect body and rock temperatures here presented are the only obtained in natural habitats for this or other triatomines.

Differential susceptibility of BALB/c, C57BL/6N, and CF1 mice to photoperiod changes

Objective:Circadian disturbances common to modern lifestyles have been associated with mood disorders. Animal models that mimic such rhythm disturbances are useful in translational research to explore factors contributing to depressive disorders. This study aimed to verify the susceptibility of BALB/c, C57BL/6N, and CF1 mice to photoperiod changes.Methods:Thermochron iButtons implanted in the mouse abdomen were used to characterize temperature rhythms. Mice were maintained under a 12:12 h light-dark (LD) cycle for 15 days, followed by a 10:10 h LD cycle for 10 days. Cosinor analysis, Rayleigh z test, periodograms, and Fourier analysis were used to analyze rhythm parameters. Paired Student's t test was used to compare temperature amplitude, period, and power of the first harmonic between normal and shortened cycles.Results:The shortened LD cycle significantly changed temperature acrophases and rhythm amplitude in all mouse strains, but only BALB/c showed altered period.Conclusion:These findings suggest that BALB/c, the preferred strain for stress-induced models of depression, should also be favored for exploring the relationship between circadian rhythms and mood. Temperature rhythm proved to be a useful parameter for characterizing rhythm disruption in mice. Although disruption of temperature rhythm has been successfully documented in untethered mice, an evaluation of desynchronization of other rhythms is warranted.