Growth-related changes in histology and immunolocalization of steroid hormone receptors in gonads of the immature male green turtle (Chelonia mydas).
Studies on the population dynamics of sea turtles require histological evaluation of the ontogenetic development and the activity of the gonads for reproduction. To investigate the growth-related changes of gonads in the immature male green turtle (Chelonia mydas), the histological changes of testes and epididymides and the localization of the androgen receptor, estrogen receptor alpha, estrogen receptor beta, and progesterone receptor were examined. The testes were categorized histologically into six developmental stages, and a scarce relationship between straight carapace length and gonadal development was confirmed based on the histological analysis. Several kinds of steroid hormone receptors were examined to show distributions in both testes and epididymides, for which their immunoreactivities were enhanced according to the developmental stage of the testes. These results suggest that straight carapace length is not an adequate indicator of maturity determination, whereas histological and immunohistochemical evaluations are useful in identifying the growth stages of green turtles, owing to the higher sensitivity to steroid hormones that appear during growth.
Otsuka
Saori
S
Laboratory of Anatomy, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan.
Suzuki
Masatsugu
M
Kamezaki
Naoki
N
Shima
Tatsuya
T
Wakatsuki
Motoki
M
Kon
Yasuhiro
Y
Ohtaishi
Noriyuki
N
D000818:Animals; D004822:Epididymis / Q000254:growth & development* / Q000378:metabolism; D047628:Estrogen Receptor alpha / Q000378:metabolism; D047629:Estrogen Receptor beta / Q000378:metabolism; D007150:Immunohistochemistry / Q000662:veterinary; D008297:Male; D009929:Organ Size / Q000502:physiology; D011944:Receptors, Androgen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D011987:Receptors, Steroid / Q000378:metabolism*; D013737:Testis / Q000033:anatomy & histology / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D014426:Turtles / Q000033:anatomy & histology / Q000254:growth & development* / Q000378:metabolism
D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D011944:Receptors, Androgen; D011980:Receptors, Progesterone; D011987:Receptors, Steroid