Here, we report that the gross morphology of the testes changes under ‘non-mating' or ‘mating' conditions in medaka (Oryzias latipes). During these conditions, an efferent duct expands and a histological unit of spermatogenesis, the lobule, increases its number under ‘non-mating' conditions. Based on BrdU labeling experiments, lower mitotic activity occurs in gonial cells under ‘non-mating' conditions, which is consistent with the reduced number of germ cell cysts. Interestingly, the total number of type A spermatogonia was maintained, regardless of the mating conditions. In addition, the transition from mitosis to meiosis may have been retarded under the ‘non-mating' conditions. The minimum time required for germ cells to become sperm, from the onset of commitment to spermatogenesis, was approximately 14 days in vivo. The time was not found to significantly differ between ‘non-mating' and ‘mating’ conditions. The collective data suggest the presence of a mechanism wherein the homeostasis of spermatogenesis is altered in response to the mating conditions.
How to translate text using browser tools
13 July 2021
Dynamics of Spermatogenesis and Change in Testicular Morphology under ‘Mating’ and ‘Non-Mating’ Conditions in Medaka (Oryzias latipes)
Ruka Sumita,
Toshiya Nishimura,
Minoru Tanaka
Zoological Science
Vol. 38 • No. 5
October 2021
Vol. 38 • No. 5
October 2021
efferent duct
environment
gametogenesis
mating conditions
mitotic activity
spermatogonia