ABSTRACT
OBJECTIVE: To obtain information on the toxicity of lufenuron on the reproduction ability and the growth and development of offspring in female and male rats through two-generation reproduction toxicity study. METHODS: The specific pathogen free healthy SD rats were randomly divided into control group and low-, medium-and high-dose lufenuron groups, with 60 rats in each group, half females and half males. Rats in the low-, medium-and high-dose lufenuron groups were respectively fed with lufenuron at the dose of 5.0, 20.0 and 80.0 mg/(kg body weight·day) for 8 weeks before mating. The control group was fed with standard foot. The reproductive index, brain and reproductive organ coefficients and pathological changes were observed in P and F1 parents. The birth and growth indexes of the offspring were measured. RESULTS: i) P generation: from the 14 th day, the female rats in the medium-dose group had lower body weight than that of the female control group(P<0.05); from the 35 th day, the body weight was lower than that of the female low-dose group(P<0.05). From the 14 th day, the female rats in the high-dose group had lower body weight than that of the other three female groups(P<0.05). From the 14 th day, the male rats in the medium-and high-dose groups had lower body weight than that of the male control group and low-dose group(P<0.05). The body weight of pregnant rats in the parental high-dose group was lower than that of the control group, low-dose group, and medium-dose group at day 0, 7, 14, 19 of the pregnancy duration(P<0.05). The body weight of pregnant rats in the parental medium-dose group was lower than that of the low-dose group on day 0 of the pregnancy duration, and lower than that of the control and low-dose groups on day 7 and 14(P<0.05). The conception rate, the new-borne survival rates and the feeding survival rate of female rats in the high-dose group was lower than that of the other three female groups(P<0.008). The new-borne feeding survival rate of female rats in the medium-dose group was lower than that of the control group and low-dose group(P<0.008). The organ coefficients of brain in female rats in the medium-and high-dose groups were higher than that of the female control group and low-dose group(P<0.05). The organ coefficients of brain and testis in male rats in the medium-and high-dose groups were higher than that of the control group and low-dose group(P<0.05). The organ coefficient of epididymis in male rats in the high dose group was lower than that of the other three male groups(P<0.05). ii) F1 generation: the body weight of female rats in the low-and medium-dose group was higher than that of the female control group on the 42 th day(P<0.05). The body weight of male rats in the low-dose group was higher than that of the male control group on the 42 th, 49 th, and 56 th days(P<0.05). The body weight of male rats in the medium-dose group was higher than that of the male control group on the 14 th, 21 th, 42 th, 49 th, and 56 th days(P<0.05). The new-borne survival rate in the low-dose group was lower than that of the control group(P<0.017). The body weight of new-borne rats in the high-dose group on day 4 of birth was lower than that in the other three female groups(P<0.05). iii) F2 generation: the body weight of male rats in the male medium-dose group was lower than that in the control group on day 21 of birth(P<0.05). CONCLUSION: The reproductive and developmental toxicity of lufenuron is found in rats in the medium-and high-dose groups. Toxicities including low body weight, conception rate, new-borne survival rate and feeding survival rate are found in P generation; low body weight and feeding survival rate are found in F1 generation; low body weight is found in male F2 generation. The no-observed-adverse-effects levels of lufenuron in two-generation reproductive study are 5.87 mg/(kg·d) for females and 5.09 mg/(kg·d) for males in SD rats.
ABSTRACT
Cryptorchidism is associated with infertility in adulthood. Early orchiopexy is suggested to reduce the risk. Information is lacking on the potential link between infant germ cell maturation and the risk of future infertility. The objective of the study was to evaluate age-related germ cell development in cryptorchidism. Immunostaining for markers of germ cell development (octamer-binding transcription factor 3/4 [OCT3/4], placental alkaline phosphatase [PLAP], KIT proto-oncogene [C-KIT], podoplanin [D2-40], Lin-28 homolog A [LIN28], and G antigen 7 [GAGE-7]) was performed in testicular biopsies from 40 cryptorchid boys aged 4-35 months. Germ cell numbers and distributions were evaluated in cross sections of seminiferous tubules, with and without immunostaining. OCT3/4, D2-40, and LIN28 were generally expressed in the early stages of germ cell development, as shown by positive expression in germ cells in the central region of seminiferous tubules. In contrast, PLAP and GAGE-7 were expressed in both central and peripheral parts of the tubules in the early stages of development and expressed mainly in a peripheral position with advancing age. Germ cell maturation was delayed in this study population as compared with that observed in our previous study on germ cell markers in a healthy population. The number of GAGE-7-positive germ cells per tubular cross section obtained by immunostaining was significantly higher than that obtained by standard hematoxylin and eosin staining. Double immunostaining revealed heterogeneity in germ cell development in cryptorchid testes. These results shed light on the pathophysiology of germ cell development in boys with cryptorchidism.
ABSTRACT
Resumen Opsanus beta es un habitante permanente del Sistema Lagunar de Alvarado, a pesar de participar en la transferencia energética entre los distintos componentes, no hay información sobre los aspectos ecológicos y reproductivos de esta especie. El presente trabajo se desarrolló, con la finalidad de evaluar aspectos de la biología como estacionalidad, alimentación, proporción de sexos, índice gonadosomático, hepatosomático y factor de condición para ambos sexos, así como la fecundidad y la relación peso-longitud, durante el período de abril 2008 a diciembre 2012. Se registraron los parámetros de temperatura ambiental y del agua, profundidad, salinidad, oxígeno disuelto y pH en cada uno de los seis sitios de recolecta que se ubicaron en el sistema. El análisis de los parámetros ambientales no mostró diferencias significativas entre los años del período de estudio, la salinidad registrada a lo largo del estudio correspondió a un ambiente oligohalino, el resto de los parámetros fisicoquímicos presentó variaciones que pueden explicarse por el patrón climático en el área. Se capturó un total de 519 organismos, 311 (59.9 %) machos y 208 (41.1 %) hembras, el comportamiento de la longitud patrón en los distintos meses muestra que en los machos, la longitud promedio es mayor que en las hembras. El espectro trófico se compone de 13 tipos alimenticios, destacan los crustáceos, moluscos y peces, adicionalmente se observó la práctica de canibalismo en los meses de marzo y abril. Los estadios de maduración gonádica más avanzados se registraron en los meses de noviembre a marzo para los machos, y de noviembre a febrero para las hembras. El IGS registró los valores más altos en los meses de noviembre a abril, el IHS y el FC presentaron un comportamiento inverso al IGS. La fecundidad de esta especie varía de 96 a 428 ovocitos por hembra. La relación peso-longitud por sexo y temporada presentó una mayor tasa de crecimiento (b) para los machos que para las hembras, y un crecimiento de tipo alométrico negativo. La información biológica y ecológica de O. beta en el SLA permite reconocer que esta especie es importante por el papel ecológico que juega en la estructura y dinámica de sus comunidades acuáticas y puede ser utilizada en la propuesta de manejo y aprovechamiento sustentable de este ecosistema.
Abstract Opsanus beta is a permanent species in the Alvarado Lagoon System (ALS), Veracruz, and eventhough it is not of economic importance, it might be actively involved in the energy transfer of the system. Currently, there is no information about the reproductive and ecological characteristics of this common fish, so this work aimed to evaluate those aspects, and to contribute with some ecological features. For this, a total of six sampling sites were selected and studied from April 2008 to December 2012. Per site, we determined fish seasonality, feeding, sex ratio, gonadosomatic index, hepatosomatic and condition factors for both sexes, as well as the fecundity and length-weight relationships. We also considered some environmental parameters such as temperature, water temperature, depth, salinity and pH. Our results on the environmental parameters analysis did not show significant differences for the study period; besides, salinity data confirmed an oligohaline environment, and the rest of the physico-chemical parameters, varied in accordance with the climatic pattern in the area. We captured a total of 519 fishes, 311 (59.9 %) males and 208 (41.1 %) females; the proportion of males resulted favorable against females throughout the study. The standard length found along the study period showed that the average was higher in males than in females. The trophic spectrum was composed of 13 food items, principally crustaceans, molluscs and fishes; in addition, cannibalism was observed over young individuals during March and April. The most advanced stages of gonadal maturation were recorded from November to March for males, and from November to February in females; generally, the Gonadosomatic index (IGS) recorded the highest values from November to April. The Hepatosomatic Index (IHS) and the Condition Factor (FC) presented an inverse relationship with the Gonadosomatic index (IGS). The fecundity of this species ranged from 96 to 428 oocytes per female. The weight-length relationship by sexes and seasons, showed a higher growth rate for males than for females, and an allometric growth type. The biological and ecological information of O. beta in ALS evidenced the importance of this species and its ecological role in the structure and dynamics of these aquatic communities. This species may be used as a model for future proposals dealing with the management and sustainable use of this ecosystem.
ABSTRACT
Age and growth of the hybrid tilapia Oreochromis niloticus x Oreochromis aureus (Perciformes: Cichlidae) in the dam “Zimapan” Mexico. Studies on age and growth in fishes are essential to establish models on population dynamics. The previos issues were determined in this study by scale growth analyses. Between September 2003 and May 2004, 382 organisms were captured using gill and atarraya nets. Eight samples were developed every month a long this study. Standard length in centimeters (Le), total weight in grams (Pt), scale length in centimeters (Lesc) and growth rings were determined. The size and weight ranged from 38 to 232mm (Le) and 8.7 to 311.9g (Pt), respectively. The growth rings analyses reveal four age groups, being the sec-ond group the most representative with 34.3% of the total sampled. The scale ring analyses showed two growth rings, one develops between November-January and the other between April-May, in good correlation with low temperature and gonad development, respectively. The growth parameters were established as: L∞=281.1mm, W∞=877.1g, K=0.33 and T0=0.88year -1. The growth curves based on length and weight were described by using the von Bertalanffy model: Le =28.11[1-e-0.33(t+0.88)] and Pt =877.17[1-e-0.33(t+0.88)]³. Finally, it is concluded that commercial catches in this dam are between a year and year and half-old when exploited. Rev. Biol. Trop. 59 (2): 761-770. Epub 2011 June 01.
La edad y crecimiento de la tilapia Oreochromis niloticus x Oreochromis aureus fueron determinados por medio de la lectura de escamas. Un total de 382 individuos fueron capturados mediante el uso de redes agalleras y atarrayas. Ocho recolectas mensuales se llevaron a cabo entre septiembre 2003-mayo 2004; se registraron los datos de longitud estándar en cm. (Le), el peso total en g (Pt) y se obtuvieron muestras de escamas para registrar el largo de la escama en mm. (Lesc) y el número de anillos de crecimiento formados. Las tallas y pesos de recolecta variaron entre 38 a 232mm (Le) y de 8.7 a 311.9g de peso total (Pt) respectivamente. El recuento de los anillos anuales en escamas, permitió establecer cuatro grupos de edad, siendo el grupo de edad 2 el más representativo, con un 34.3% de la población muestreada. El cálculo de los incrementos marginales del crecimiento mensual de las escamas, sugirió la formación de dos anillos, uno de ellos se forma en los meses de noviembre-enero y otro en los meses de abril-mayo, los cuales coinciden con la época de bajas temperaturas y de madurez gonádica respectivamente. Los parámetros de crecimiento quedaron establecidos en: L∞=281.1mm, W∞=877.1g, K=0.33 y T0=0.88/año. Las curvas de crecimiento en longitud y peso se describieron mediante las ecuaciones de von Bertalanffy: Le=28.11 [1- e-0.33(t+0.88)] y Pt=877.17 [1-e-0.33(t+0.88)]³. Finalmente, se concluyó que los peces que se explotan en la represa mediante captura comercial presentan entre un año y año y medio de edad.
Subject(s)
Animals , Tilapia/growth & development , Chimera , Growth Charts , Mexico , Population Dynamics , Seasons , Tilapia/anatomy & histology , Tilapia/classificationABSTRACT
O uso de animais isogênicos apresenta grandes vantagens experimentais, como uniformidade fenotípica e genotípica (reduzindo o número de animais em experimentos) e histocompatibilidade, permitindo, assim, o acúmulo de informações e a repetibilidade dos experimentos. A linhagem isogênica de Rattus norvegicus Fischer 344 existe há 90 anos, entretanto pouco se sabe sobre as razões de seu baixo índice reprodutivo. O presente estudo demonstrou que ratos Fischer F344 são fotorresponsivos quanto à reprodução, tendo seus índices de prenhezes acrescidos com o aumento do fotoperíodo. Os melhores índices são obtidos quando os machos são submetidos a 14 horas de luz e fêmeas a 16 horas de luz, indicando dimorfismo sexual na fotorresponsividade.
The use of isogenic animals presents great experimental advantages, as phenotypic and genotypic uniformity (reducing the number of experimental animals) and histocompatibility, thus allowing, the accumulation of information, and the repeatability of the experiments. The isogenic strain of Rattus norvegicus Fischer 344 has existed for 90 years, however the reasons of its low reproductive index are not knew. The present study has demonstrated that Fischer F344 rats are photoresponsive regarding reproduction, having improved its pregnancy index with the increase of the photoperiod. The best indexes were achieved when the males had been submitted to 14 hours of light and females to 16 hours of light, indicating sexual dimorphism in photoresponsivity.