Análise morfológica e funcional do processo espermatogênico em cobaios (Cavia porcellus) da pré-puberdade até a pós-puberdade

Abstract

Pesq. Vet. Bras. 33(Supl.1):1-7, dezembro 2013 1 semanas de idade (N=5/grupo). Os aspectos analisados incluíram a contagem das populações celulares presentes no estádio 1 do ciclo do epitélio seminífero (CES), eficiên-cia das mitoses espermatogoniais (RMi), produção meió-tica (RMe), rendimento geral da espermatogênese (RGE), índice de células de Sertoli (ICS) e capacidade de suporte das células de Sertoli (CSCS). Os resultados mostraram que número médio de espermatogônias A, espermatócitos primários em pré-leptóteno/leptóteno, espermatócitos primários em paquíteno, células espermatogênicas totais e células de Sertoli mostraram variações numéricas em funAnálise morfológica e funcional do processo espermatogênico em cobaios (Cavia porcellus) da pré-puberdade até a pós-puberdade This study describes the morphological and functional analysis of spermatogenesis in guinea pigs (Cavia porcellus) with five (W5), six (W6), nine (W9) and eleven (W11) weeks of age (n=5/group). The aspects analyzed include counts of cell populations present in stage 1 of seminiferous epithelium cycle (SEC), efficiency of spermatogonial mitosis (EMi), meiotic production (EMe), overall yield of spermatogenesis (EOS), Sertoli cell index (SCI) and carrying capacity of Sertoli cells (CCSC). The results showed that the average number of spermatogonia type A, primary spermatocytes in pré-leptóteno/leptóteno, primary spermatocytes in pachytene, total spermatogenic cells and Sertoli cells showed numerical variations according to age; however they were statistically not detected, while round spermatids increased significantly at puberty and then stabilized. The spermatogenic production of 5 to 11-week-old guinea pigs did not reach the stabilization point, and the RMi, RME, EOS, SCI and CCSC showed significant number variation as a function of age. The results demonstrate that Cavia porcellus in post-pubertal stage 2 are an advantageous experimental model to address studies on the processes of homologous recognition, alignment, and synapsis during meiotic prophase; intrinsic yield of spermatogenesis in guinea pigs is similar to Wistar rats, paca and agouti (Dasyprocta sp.) and lower than in cavies, whereas the functional efficiency of Sertoli cells is higher than in agouti and Wistar rats, and lower than in pacas, spiny rat and collared peccaries. We conclude that in guinea pigs the spermatogenesis is fully established at 6 weeks of age, indicating the pubertal stage of sexual development, and until week 11 they do not reach the maximum daily sperm production and therefore sexual maturity. RESUMO.-Este estudo descreveu as análises morfológica e funcional do processo espermatogênico em cobaios (Cavia porcellus) de cinco (S5); seis (S6); nove (S9) e onze (S11)

Influence of racial crossing on testicular structure and spermatogenesis in sheep Santa Inês and crossbred Santa Inês and Dorper

“…The knowledge of the reproductive function has been pointed as a fundamental factor for the establishment of adequate management programs (Nunes et al, 2013). Therefore, it is essential to evaluate the reproductive capacity of the males, in order to obtain animals capable of transmitting characteristics that will improve the productive system (Pacheco and Quirino, 2010).…”

“…The yield of the spermatogenic process, obtained through the numerical ratios of the spermatogenic cells and through the sections of seminiferous tubule, allows the evaluation of the productive capacity of spermatozoa. This variation is considered a fundamental variable for the determination of males destined for reproduction, in order to know in which cellular phases occur the losses, conceding the estimation of the percentage of these cells and the comparison between the species (Assis Neto et al, 2003;Costa et al, 2004;Nunes et al, 2013).…”

Morphological development of the testicles and spermatogenesis in guinea pigs (Cavia porcellus Linnaeus, 1758)

“…Among rodents the guinea pig may be an alternative as animal model for studying human reproduction, by presenting a long gestational period, spontaneous ovulation, and active corpus luteum (SUZUKI, KOURA, NOGUCHI et al, 2003). Some information having been found regarding the accessory glands (GRADELA, NUNES, MARTINS et al, 2013a;GRADELA, NUNES, MATOS et al, 2013b), characterization of mammalian early meiotic gene expression (RODRIGUEZ-CASURIAGA, GEISINGER, SANTINAQUE et al, 2011), biochemical and molecular analysis of early meiotic prophase stages (RODRIGUEZ and WETTSTEIN 2004) and morphological and functional analysis of spermatogenesis (NUNES, GOUVEIA, MATOS et al, 2013).…”

The quantification of testicular cells during the postnatal development in two Caviomorph rodents: the guinea pig (Cavia porcellus) and the cutia (Dasyprocta agouti)

“…Several studies have quantified the testicular cells using different techniques, as proposed by Bellvé et al (1977), but most of then use histomorphometry (Nunes et al 2013, De Melo et al 2013, Morais et al 2014. Thus, this work aims to estimate the number of testicular cells in two Caviomorph rodents during the postnatal development, applying design-based stereological techniques as an accurate tool.…”