In the species of bats that present a asynchronous reproductive pattern
(Corynorhinus mexicanus), spermatogenesis is in recess during autumn and winter,
when androgen levels are low, but the secondary sexual functions are maintained and
mating takes place. The proliferation of spermatogonia and the spontaneous
degeneration of spermatocytes often coincide during normal testicular functioning in
mammals, and this is where apoptosis plays a central role in controlling the number of
testicular germ cells. The spermatogonia are the cells that frequently suffer apoptosis in
the testicles, but this process can also affect spermatocytes and spermatids. This
emphasizes the need to improve our understanding of the participation of apoptosis
and, therefore, its modulation during testicular development and training of new blood
vessels. The strict regulation of angiogenesis and its adequate functioning are very
important for organisms, since both the excessive formation and the insufficient
development of blood vessels can cause severe diseases. Studies of the formation and
involution of testicular blood vessels in seasonal reproductive bat species may thus
shed new light on understanding the control and development of angiogenesis in
mammals. Using the C. mexicanus bat as a study model of the seasonal activity of the
testicle, we determine for the first time the involvement of the apoptosis in developing
testicular vasculature in a seasonal chiropteran with drastic morphological changes of
the testes, although more comparative studies are needed, mainly one between the
different stages of testicular cycle which can provide information of the existence of
angiogenesis associated with the testicular cycle in these species.
Keywords: Apoptosis, Bats, Blood vessels, Seasonal reproduction, Testicles.
