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Abstract. The aim of this study was to evaluate the phases of sexual development and spermatogenesis of Spix's yellowtoothed cavy (Galea spixii) based on analyses of the structural components of the testes. The testes of animals from 0 to 150 days of age were collected by orchiectomy, weighed, and processed for analysis by light microscopy. At 45 days of age, spermatozoa were seen in the tubular lumen. Spermatogenesis was not established in animals from 45 to 150 days of age. The stages of sexual development may be classified into the following phases: from birth to the age of 15 days (immature); 30 days of age (prepubertal); 45-105 days of age (pubertal); and 120 and 150 days of age (postpubertal). This is the first study to address the male reproductive biology of Spix's yellow-toothed cavy.

The aim was to study the ultrastructure of testicular parenchyma and define the morphological ultrastructure of spermatozoa of agoutis kept in captivity. Segments of testes from eight agouti males at prepubescence, prepuberty, pubescence and sexual maturity were fixed in glutaraldehyde. Laboratory procedures were performed for transmission electron microscopy. Spermatogonial cells of Type A - pale, Type A - dark, intermediate and Type B were found. Spermatocytes in the pachytene phase were abundant among primary spermatocytes. From the prepubertal phase, Sertoli cells exhibited invaginations in the nuclear membrane and lipid inclusions in the cytoplasm due to their phagocytic function. Leydig cells displayed higher metabolic activity during puberty as evidenced by the presence of lipid droplets. Spermatozoa were fully formed morphologically at prepuberty. The centriolar complex had partially degenerated and featured a centriolar space as in rodents. Sperm heads were tapered, without prominence of the acrosome or evidence of the perforatorium, differing from cavies, rats and mice. This is the first study to describe the ultrastructure of agouti spermatozoa. This research may assist as a basis for future work related to fertility and other biotechnologies applied to reproductive biology in agoutis.

The androgen/estrogen balance is essential for normal sexual development and reproduction in mammals. Studies performed herein investigated the potential for estrogen synthesis in cells of the testes of a hystricomorph rodent, The study characterized the expression of the key enzymes responsible for estrogen and androgen synthesis, cytochromes P450 aromatase (P450arom), 17α-hydroxylase/17,20-lyase (P450c17) respectively, as well as the redox partner NADPH cytochrome P450 oxido-reductase (CPR) required to support electron transfer and catalysis of these P450s, by immunohistochemistry (IHC) and quantitative polymerase chain reaction (qPCR) analysis, throughout postnatal sexual development. Testes (immature, pre-pubertal, pubertal and post-pubertal) were collected, fixed for IHC (CYP19, CYP17 and CPR) and stored frozen for qPCR for the relevant gene transcripts ( and ). Expression of P450c17 was significantly elevated at the pre-pubertal and pubertal stages. Based on IHC, P450c17 was expressed only in Leydig cell clusters. The expression of P450arom was detectable at all stages of sexual development of IHC data suggest that estrogen synthesis was not restricted to somatic cells (Leydig cells/Sertoli cells), but that germ cells may also be capable of converting androgens into estrogens, important for testicular function and spermatogenesis.

Resumo.-Callithrix jacchus e Callithrix penicillata são primatas de pequeno porte cuja utilização como modelo anatômico tem se mostrado cada vez mais frequente, não somente pela praticidade no manuseio como facilidade no trato em criatório e sua taxa de reprodução. Este estudo teve como objetivo descrever os componentes dos plexos braquial em Callithrix jacchus e penicillata. Para tanto, três espécimes com aproximadamente 8 anos e 240 g foram fixados em solução de formaldeído a 10%, e posteriormente dissecados e fotodocumentados. O plexo braquial do Callithrix jacchus e penicillata originou-se dos nervos espinhais C5 a T1 constituindo os troncos cranial, médio e caudal. A composição do plexo braquial destes animais se assemelha ao de outros primatas, bem como a outros mamíferos. INTRODUÇÃOOs saguis de tufo branco e de tufo preto (Callithrix jaccus e Callithrix penicillata) são primatas diurnos cujas características sociais e reprodutivas, associadas à facilidade no trato e seu pequeno porte, os tornam modelos apropriados para pesquisas de comportamento, reprodução, infectologia e neurocientificas (Mansfield 2003).Endêmicos do Brasil, os saguis de tufos brancos e saguis de tufos pretos não estão entre os animais em risco de extinção. Pelo contrário, a ação antrópica sobre os animais e seu habitat (principalmente mata atlântica e cerrado) tem gerado a disseminação destes primatas para regiões onde estes passam a ser invasores, colocando em risco outras espécies (Ruiz-Miranda et al. 2006, Morais Jr 2010.Diferentemente de outros primatas, saguis possuem uma dieta abrangente que inclui insetos, moluscos, frutos, exsudados, pequenos vertebrados, sementes, ovos de aves e néctar. Saguis vivem em famílias, as fêmeas possuem gestação de 5 meses e, em sua maioria, resulta na geração de gêmeos (Abbott et al. 2003, Reis et al. 2006 The aim of this study was to describe the components of the brachial plexus in Callithrix jacchus and C. penicillata. Three specimens about 8 years old and weighing 240g were fixed in 10% formaldehyde and subsequently dissected and photodocumented. The brachial plexus of Callithrix jacchus and C. penicillata originates from the spinal nerves C5 to T1 in continuation of the cranial, medium and flow trunk. The composition of the brachial plexus of these animals is similar to the one of other primates ands other mammals.INDEX TERMS: Brachial plexus, Callithrix jacchus, Callithrix penicillata, white tuft marmoset, black tuft marmoset, nervous system, peripheral nerves.

Pesq. Vet. Bras. 32(Supl.1):84-90, dezembro 2012 84 de 48 dias e uma ninhada de 2 a 4 crias. O objetivo deste estudo foi caracterizar histologicamente os componentes estruturais dos órgãos genitais de preás machos relacionando com a evolução cronológica destes órgãos na espé-cie. Foram utilizados para análise animais ao nascimento e aos 15, 30, 45, 60, 75, 90, 105, 120 e aos 150 dias de idade. Fragmentos do epidídimo, ducto deferente, pênis e glându-las sexuais acessórias foram coletados, fixados e processados para descrição em microscopia de luz. O epidídimo apresentou epitélio colunar simples e em cada fase sexual notou-se diferença quanto ao tamanho do lúmen tubular e à presença de espermatozóides no lúmen aos 45 dias de idade. O epitélio do ducto deferente no preá mostrou-se pseudo-estratificado colunar com crescente presença de estereocilios com o avanço da idade. A glândula vesicular no preá apresentou uma mucosa com pregueamento va-A microestrutura e o desenvolvimento dos órgãos genitais masculinos de preás (Galea spixii) criados em cativeiro¹ The Spix's yellow-toothed cavy (Galea spixii) from the Brazilian northeastern semi-arid is a rodent that does belong to the family Caviidae. They are found in regions of the Caatinga and Cerrado, and reproduces throughout the year, with a gestation period of 48 days and a litter of 2 to 4 pups. The aim of this study was to characterize histologically the structural components of the genital organs of male Spix's yellow-toothed cavies regarding their chronological development. For the analysis we used animals at birth and with 15, 30, 45, 60, 75, 90, 105, 120 and 150 days of age. Fragments of the epididymis, vas deferens, penis and accessory sex glands were collected, fixed and processed for light microscopic. The epididymis had a simple columnar epithelium and at each sexual stage the epididymis was noted different in size of the tubular lumen and regarding the presence of sperm in the lumen at 45 days of age. The epithelium of vas deferens was found to be pseudo-stratified columnar with increasing presence of stereocilia with advancing age. The vesicular gland showed a folded mucosa that varied according to stage of sexual development. The prostate was not very developed, with a small lumen in Spix's yellow-toothed cavy at birth and at 15 days of age; at 45 days showed variable wrinkling of the epithelium. The male genital organs underwent morphological transformations in line with age and sexual development, what helped to determine the onset of puberty, which in the species studied occurred at 45 days of age.INDEX TERMS: Spix's yellow-toothed cavy, Galea spixii, sexual development, rodents, epididymis, vas deferens, accessory sexual glands.

Estudos baseados nas características testiculares estão altamente relacionados com a eficiência reprodutiva de varias espécies. Assim, o projeto desenvolvido teve como objetivo identificar as células do epitélio seminífero, caracterizar histologicamente suas associações, que formam os estádios, e determinar a frequência destes. Os fragmentos de testículos, com 30, 45, 60, 75, 90, 105, 120, 150 dias foram coletados no Centro de Multiplicação da Universidade Federal Rural do Semi-árido, Mossoró/ RN. Passando pelos processos de fixação, lavagens em soluções de concentrações crescentes de álcoois (70-100%), desidratação em xilol, inclusão em Histosec®, preparação das lâminas histológicas, colorações em Hematoxilina e Eosina (HE) e suas fotomicrografias para a caracterização dos núcleos celulares do epitélio germinativo e a definição dos oitos estágios do ciclo do epitélio seminífero (CES) baseados no Método da Morfologia Tubular. Das faixas etárias analisadas todos os animais de 90-150 dias de idade apresentaram todos os estádios do CES. Os estádios I e III foram os que apresentaram maior e menor freqüência, respectivamente. Os animais caracterizados como pré-púberes (30 dias), púberes (45-90 dias de idade) e pós-púberes (105150 dias de idade) apresentaram os estádios I, VIII e IV com uma maior freqüência, respectivamente.

The development of male sexual maturity varies among buffaloes. The Murrah buffalo is considered the most important and efficient milk and fat producer, but aspects of its reproductive biology are still unknown. The present study aimed to evaluate the daily sperm production (DSP) and spermatogenesis in developing Murrah buffalo bulls by evaluation of the seminiferous tubules, testicular morphometry and using light microscopy and scanning electron microscopy. The testes of Murrah buffalo bulls at 18 mo was immature and at 24 mo could still be considered an average-efficiency breed based on their DSP. At 24 mo, the DSP rate was 0.97 billion sperm per testis and 13 million sperm per gram of testis. However, the animals had superior morphometric parameters compared with those of other livestock animals, except for the seminiferous tubule volume and diameter, which were inferior. In conclusion, our data support former views that the testes of the Murrah breed does not reach sexual maturity before 2 y of age and that important developmental steps occur later than Murrah crossbreeds from Brazil.