Involvement of pituitary gonadotropins, gonadal steroids and breeding season in sex change of protogynous dusky grouper, Epinephelus marginatus (Teleostei: Serranidae), induced by a non-steroidal aromatase inhibitor

Two experiments were performed using the aromatase inhibitor (AI) letrozole (100mg/kg) to promote sex change, from female-to-male, in protogynous dusky grouper. One experiment was performed during the breeding season (spring) and the other at the end of the breeding season (summer). During the spring, AI promoted sex change after 9weeks and the sperm produced was able to fertilize grouper oocytes. During the summer, the sex change was incomplete; intersex individuals were present and sperm was not released by any of the animals. Sex changed gonads had a lamellar architecture; cysts of spermatocytes and spermatozoa in the lumen of the germinal compartment. In the spring, after 4weeks, 11ketotestosterone (11KT) levels were higher in the AI than in control fish, and after 9weeks, coincident with semen release, testosterone levels increased in the AI group, while 11KT returned to the initial levels. Estradiol (E2) levels remained unchanged during the experimental period. Instead of decreasing throughout the period, as in control group, 17 α-OH progesterone levels did not change in the AI-treated fish, resulting in higher values after 9weeks when compared with control fish. fshβ and lhβ gene expression in the AI animals were lower compared with control fish after 9weeks. The use of AI was effective to obtain functional males during the breeding season. The increase in androgens, modulated by gonadotropins, triggered the sex change, enabling the development of male germ cells, whereas a decrease in E2 levels was not required to change sex in dusky grouper. © 2013 Elsevier Inc.

Genetic parameters for scrotal circumference, breeding soundness examination and sperm defects in young Nellore bulls

A total of 51,161 records of scrotal circumference measurements at 18 mo of age (SCI 8) and 17,648 records of sperm defects and breeding soundness of Nellore bulls (mean age of 22.5 mo), raised under extensive conditions, were analyzed to estimate coefficients of heritability and genetic correlations of morphological semen traits by Bayesian inference. The observed semen traits were classified as minor (MID). major (MAD), and total sperm defects (TD). The animals were classified according to breeding soundness as satisfactory and unsatisfactory potential breeders. The (co)variance components and breeding values were estimated by Gibbs sampling using the GIBBS2F90 program under an animal model that included contemporary group as fixed effect, age of animal as linear covariate, and direct additive genetic effects as random effects. Heritabilities of 0.40 ± 0.02, 0.16 ± 0.02, 0.04 ± 0.01, 0.15 ± 0.01, and 0.10 ± 0.01 were obtained for SCI8, MID, MAD, TD, and breeding soundness, respectively. The SC18 showed a positive and moderate correlation with breeding soundness (0.56 ± 0.04) and a negative and low correlation with MID (-0.23 ± 0.03), MAD (-0.16 ± 0.02), and TD (-0.24 ± 0.02). In conclusion, scrotal circumference showed the best response to selection among the traits studied and was favorably correlated with breeding soundness and sperm morphology in young Nellore bulls. © 2013 American Society of Animal Science. All rights reserved.

Rotulagem ambiental: estudo de critérios para a concessão do selo verde para produtos manufaturados de couro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Strategies to improve the efficiency of genomic selection in animal breeding programs

Pós-graduação em Zootecnia - FCAV

A genomic assisted breeding program for cassava to improve nutritional quality and industrial traits of storage root

A mandioca é cultivada como "mandioca mansa" para consumo in natura e "mandioca para indústria" como fonte de amidos e farinhas. Raças locais foram utilizadas para descoberta de "mutações espontâneas" e desenvolvimento de abordagem evolutiva e de melhoramento para estudos de função gênica. Recursos de Genômica e Proteômica foram obtidos. Análises de expressão gênica por blot de RNA e microarranjos foram desenvolvidos para identificação de expressão diferencial. "Mandioca açucarada" foi identificada, sendo relacionada com falta de expressão do gene da BEI e de uma mutação "nonsence" na sequência do gene GBSSI causando a formação do amido serose. "Mandioca avermelhada" apresentou falta de expressão do gene CasLYB, e a "amarela" uma regulação de repressão do gene CasHYb. Análise Proteômica do complexo carotenóide-proteína, juntamente com a análise de expressão de gene da CAP4, revelaram uma dupla fita de cDNA associada ao elevado acúmulo de carotenóide. Sequenciamento do gene da GBSSI identificou 22 haplótipos e grande diversidade de nucleotídios. Populações segregantes de cruzamentos de fenótipos bioquímicos diferenciados com cultivares elites dos Cerrados foram obtidas.

Accuracy of genomic predictions in Bos indicus (Nellore) cattle

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Genomic selection and assisted reproduction technologies to foster cattle breeding

Genomics has been propagated as a paradigm shifting innovation in livestock during the last decade. The possibility of predicting breeding values using genomic information has revolutionized the dairy cattle industry and is now being implemented in beef cattle. In this paper we discuss how genomics is changing cattle breeding through genomic selection, and how this change is creating new ways to articulate assisted reproduction technologies with animal breeding. We also debate that the scientific community is still starting the long journey to reveal the functional aspects of the cattle genome, and that knowledge in this field is the frontier to a whole new venue for the development of novel applications in the livestock sector.

Kin-bias, breeding site selection and female fitness in a cannibalistic Neotropical frog

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Breeding sites of the leaf frog phyllomedusa tetraploidea (hylidae, phyllomedusinae) in a forest remnant in southern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Corn production for silage intercropped with forage in the farming-cattle breeding integration

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The development of genomics applied to dairy breeding

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)