Stages and duration of the seminiferous epithelium cycle in the bat Sturnira lilium

Abstract

Knowledge of the stages that compose the seminiferous epithelium cycle (SEC) and determination of the duration of spermatogenic processes are fundamental for the accurate quantification of the dynamics of spermatogenesis. The aim of this study was to characterize the stages that compose the SEC of the bat Sturnira lilium, including evaluation of the average frequency of each of these stages throughout the year and calculation of the duration of the spermatogenic process. An ultrastructural characterization of the formation of the acrosomal cap was also performed. Testicular fragments were processed for morphological and immunohistochemical analysis as well as ultrastructural analysis using transmission electron microscopy. According to the tubular morphology method, the SEC in S. lilium is divided into eight stages, following the pattern found in other mammals. Primary spermatocytes were found at zygotene in stage 1 of the cycle. There was no variation in frequency of each of the stages over the seasons, with stage 1 being the most frequent, and stage 7 the least frequent. The duration of one seminiferous epithelium cycle was 3.45 days, and approximately 15.52 days were required for the development of sperm from spermatogonia. Ultrastructural characterization allowed the formation of the acrosomal cap in round spermatids to be monitored. In conclusion, the stages that compose the SEC in S. lilium are generally similar to those described for other mammals, but the duration of the spermatogenic process is shorter than previously recorded for mammals. The presence of primary spermatocytes at zygotene in stage 1 of the cycle is probably due to the longer duration of this stage.

Testis Morphometry and Stages of the Seminiferous Epithelium Cycle in an Epididymal Sperm-storing Neotropical Vespertilionid,Myotis levis(Chiroptera)

“…The presence of eight stages of the SEC, based on tubular morphology (Clermont, ), described for yellowish myotis (present study) has been similarly described for the Neotropical phyllostomid bats Artibeus lituratus , Artibeus planirostris , Carollia perspicillata , Platyrrhinus lineatus and Sturnira lilium (Beguelini et al., ; Oliveira et al., ; Morais et al., ), but not for the vespertilionid M. nigricans in which different cell associations were registered in seminiferous tubule cross‐sections (Beguelini et al., ).…”

Annual male reproductive activity and stages of the seminiferous epithelium cycle of the large fruit-eating Artibeus lituratus (Chiroptera: Phyllostomidae)

“…One exception is the vespertilionid Myotis nigricans, in which different cell associations occur in cross-sections of the seminiferous tubule (BEGUELINI et al 2009). The species-constant relative frequencies of stages of the SEC (HESS & FRANÇA 2007) were confirmed by our study and, similarly to the results of a study on Sturnira lilium (E. Geoffroy, 1810) (MORAIS et al 2013), no differences were detected between the rainy and the dry seasons. The smaller accumulated frequency of premeiotic stages with respect to post-meiotic stages, obtained in the present study, was similar to the results of BEGUELINI (2009).…”

“…The eight stages of the SEC previously described for this species (BEGUELINI et al 2009) have been confirmed in the present study. In general, the cellular composition of these stages is similar to that of other mammals, including other Neotropical phyllostomids (BEGUELINI et al 2009, OLIVEIRA et al 2009, MORAIS et al 2013. One exception is the vespertilionid Myotis nigricans, in which different cell associations occur in cross-sections of the seminiferous tubule (BEGUELINI et al 2009).…”

“…These stages follow one another in time, characterizing the seminiferous epithelium cycle. Based on the tubular morphology method, eight stages have been described for the seminiferous epithelium cycle of mammals (BERNDTSON 1977FRANÇA & RUSSELL 1998, including Neotropical bats (BEGUELINI et al 2009, OLIVEIRA et al 2009, MORAIS et al 2013.…”

Modification of sperm quality after sexual abstinence in Seba's short-tailed bat,Carollia perspicillata

“…In humans, a 3-day period of sexual abstinence provides optimal sperm quality (Levitas et al, 2005;Marshburn et al, 2014). Moreover, such a short abstinence period may not allow modifications of the sperm structure to take place (Morais et al, 2013). Under the assumptions that sneaker males copulate less frequently than harem males, and that 3 days of sexual abstinence is common for them, we predicted that sneaker males should not show changes in the SOD and MDA ratios, blood GSH ratio or sperm quality.…”