Stages and duration of the cycle of the seminiferous epithelium in oncilla (Leopardus tigrinus, Schreber, 1775)

Abstract

Six adult Leopardus tigrinus (oncilla) were studied to characterize stages of the seminiferous epithelium cycle and its relative frequency and duration, as well as morphometric parameters of the testes. Testicular fragments were obtained (incisional biopsy), embedded (glycol methacrylate), and histologic sections examined with light microscopy. The cycle of the seminiferous epithelium was categorized into eight stages (based on the tubular morphology method). The duration of one seminiferous epithelium cycle was 9.19 d, and approximately 41.37 d were required for development of sperm from spermatogonia. On average, diameter of the seminiferous tubules was 228.29 μm, epithelium height was 78.86 μm, and there were 16.99 m of testicular tubules per gram of testis. Body weight averaged 2.589 kg, of which 0.06 and 0.04% were attributed to the testis and seminiferous tubules, respectively. In conclusion, there were eight distinct stages in the seminiferous epithelium, the length of the seminiferous epithelium cycle was close to that in domestic cats and cougars, and testicular and somatic indexes were similar to those of other carnivores of similar size.

Evaluation of the Cell Population of the Seminiferous Epithelium and Spermatic Indexes of the Bat Sturnira lilium (Chiroptera: Phyllostomidae)

“…The testicular histoarchitecture of S. lilium followed the organization pattern observed in other bats [22], [27]–[30], and mammalian species [12], [15], [24], [25], [31]–[35]. The percentage of testicular parenchyma represented by the tunica albuginea was in agreement with that reported for several mammalian species [12].…”

“…The tubular diameter values were close to the lowest values observed for other mammals, whose range is 133–300 µm [12], [22], [23], [31], [32], [35]–[37]. Similarly, the height of the seminiferous epithelium was among the lowest ever observed values for mammals, from 31 to 100 µm [22]–[24], [31], [34], [37]–[39].…”

“…Along with the tubular length, the TSI was 5 times higher than the observed to larger mammals species, such as C. thous [24] and the oncilla Leopardus tigrinus [35]. However, TSI in S. lilium was about 1.8 times lower than that reported for other Chiroptera [22] and 2.4 times lower than that reported for the mouse [37].…”

Seasonal variation of energy reserves and reproduction in neotropical free-tailed bats Molossus molossus (Chiroptera: Molossidae)

“…This hypothesis is supported by the increase in the tubulesomatic index, gonadosomatic index and testicular weight in the fall, compared to the lower values found in the previous season (summer). While the gonadosomatic index represents the percentage of body mass that corresponds to the testis, the tubulesomatic index is a parameter used to quantify the investment in seminiferous tubules in relation to body mass (Balarini et al, 2011).…”

“…We obtained 3 mm thick semi-serial sections, with 40 mm intervals between two successive cuts, thus avoiding analyzing the same seminiferous tubule. Preparations were stained with toluidine blue/sodium borate 1%, mounted with Entellan® (Merck), and analyzed under a light microscope (Balarini et al, 2011). The gonadosomatic index (GSI) was obtained to determine the percentage of body weight occupied by both testes by the formula: GSI = TW / BW x 100, where TW = total weight of the gonads, and BW = body weight.…”