Seminiferous epithelium cycle and its duration in capybaras (Hydrochoerus hydrochaeris)

Development of spermatogenesis in captive-bred Spix's yellow-toothed cavy (Galea spixii)

“…The mean numbers of spermatocytes I in the preleptotene/leptotene and pachytene stages in Spix's yellow-toothed cavy in this study were lower than those in the Piau pigs studied by França (1991). Similarly, the number of round spermatids was lower than in swine França 1987), collared peccaries ) and capybara (Paula et al 1999) in previous studies. The Sertoli cell population was found to be stable, with an increase at postpubertal sexual phase.…”

Testicular Histomorphometric Evaluation of Zebu Bull Breeds

“…This genetic improvement can also be observed in the increased scrotal circumference of selected herds (Viu et al 2006;Martins et al 2011;Pinho et al 2013). The use of the scrotal circumference as the main parameter for the selection of bulls for breeding involves selecting the animals with higher sperm production and an increased testicular volume, which directly implies changes in the functional morphology of this organ and justifies the need for periodic updates of these measurements to characterize the evolution of the morphometric indexes of the testicular parenchyma (Unanian et al 2000;Andreussi et al 2013).The volumetric proportion of Leydig cells in the intertubular tissue and the quantitative parameters directly related to the seminiferous tubule, such as the tubule diameter, the thickness of the seminiferous epithelium and the tubule length (total length and length per gram of testicular parenchyma), are positively correlated with spermatogenic activity, providing information regarding the level of spermatogenic activity and constitute indicators of this activity in investigations involving testicular function (França and Russell 1998;Paula et al 1999). Despite the great importance of zebu cattle in tropical regions, there are few published studies on the process of spermatogenesis in these animals.…”

The Cycle of the Seminiferous Epithelium in the Greater Japanese Shrew Mole, Urotrichus talpoides.

“…At this point, the acrosomal formation in the greater Japanese shrew mole was more similar to that in the Spanish mole (Talpa occidentalis) [27] and European common shrew (Sorex araneus ) [22] than in the musk shrew and Watase's shrew. It is well known that insectivores have a large acrosome in comparison with other mammalian species [22]. The development of the large acrosome should have a strong relation with the peculiar acrosomal formation in insectivores.…”

“…The spermatid nucleus of the greater Japanese shrew mole also remained in the middle region of the seminiferous epithelium and only the acrosome extended towards the basement membrane, though the elongation of the acrosome was not prominent. Similar to the greater Japanese shrew mole, in the Spanish mole [27] and European common shrew [22], the spermatids' nucleus remained in the middle region of seminiferous epithelium and only the acrosome extended towards the base to a lesser degree. At this point, the acrosomal formation in the greater Japanese shrew mole was more similar to that in the Spanish mole (Talpa occidentalis) [27] and European common shrew (Sorex araneus ) [22] than in the musk shrew and Watase's shrew.…”

“…Similar to the greater Japanese shrew mole, in the Spanish mole [27] and European common shrew [22], the spermatids' nucleus remained in the middle region of seminiferous epithelium and only the acrosome extended towards the base to a lesser degree. At this point, the acrosomal formation in the greater Japanese shrew mole was more similar to that in the Spanish mole (Talpa occidentalis) [27] and European common shrew (Sorex araneus ) [22] than in the musk shrew and Watase's shrew. It is well known that insectivores have a large acrosome in comparison with other mammalian species [22].…”