Sexual Segment Of The Kidney Research Articles

Histology of the reproductive tract of hybrids between gonochoristic males and parthenogenetic females of Lepidodactylus lugubris in French Polynesia (Reptilia, Gekkonidae).

Parthenogenetic populations of the gecko Lepidodactylus lugubris are widespread throughout Polynesia. They often occur parapatrically, and occasionally syntopically, with the increasingly rare bisexual populations. In these instances, a small number of hybrid individuals occur and include both "female" and "male" external phenotypes, both with greatly reduced gonads. Histological examination demonstrates that these hybrids possess small ovotestes. The differentiation of the cortical tissue is identical in both "male" and "female" hybrids, but the medullary tissue is more developed in "males." The remainder of the genital tract in "females" resembles that of fertile females in the parthenogenetic and bisexual populations. By contrast, the "male" hybrids are markedly intersexual. In one of the two specimens autopsied, the hemipenes are more or less the same size as those of bisexual males, and the sexual segment of the kidney is hypertrophied and serous. In the other hybrid "male," the hemipenes have a structure similar to that seen in females, and the sexual segment of the kidney is poorly differentiated. In both hybrid "males," the ductus deferens is extremely narrow and further reduced in its middle portion; oviducts are present and resemble those of normal or hybrid females. Thus, embryonic-like gonads are associated with complete and normal female reproductive ducts in hybrid "females." Hybrid "males" also have embryonic-like gonads and feminized genital ducts but associated with secondary sexual characters that match those of sexually active or quiescent normal males.

Male reproductive biology of the southeastern crowned snake (Tantilla coronata)

Abstract The spermatogenic cycle of Tantilla coronata is post-nuptial. Spermatogenesis begins in May and reaches a peak in July and August. The sexual segment of the kidney has a cycle opposite that of the testis. Hypertrophy of the sexual segment occurs in the early spring (May) and summer july-September). Mating occurs during the period of sexual segment hypertrophy. The youngest males examined (approximately 1 2 months of age) begin spermatogenesis at the same time of year as adults, and the course of spermatogenesis appears similar to adults. It appears, however, that insufficient sperm are produced to permit successful mating following the first spermatogenic season. During the second spermatogenic season, enough sperm are produced to permit mating in the summer or following spring.

The male reproductive cycle of the rough green snake (Opheodrys aestivus)

Opheodrys aestivus is a slender, arboreal colubrid snake inhabiting the south-cast quarter of the U.S.A. Males reach sexual maturity (begin spermatogenesis) in their second calendar year of life (12 months of age). During the first spermatogenic season, enough sperm are produced to permit mating in the following spring. The spermatogenic cycle in this species is post-nuptial. Spermatogenesis begins in June and reaches a peak in July and August. The sexual segment of the kidney and plasma testosterone levels have a cycle opposite to that of the testis. Peak levels of testosterone and secretory activity of the sex segment occur in the early spring (April) and late summer (August). The occurrence of a late summer increase in testosterone and sex segment of the kidncy is discussed in relation to season of mating.

Effect of gonadotropins and testosterone on the initiation of spermatogenesis in the hypophysectomised Indian house lizard, Hemidactylus flaviviridis Ruppell.

AbstractThe action of gonadotropins (FSH, LH, PMS, and HCG) and testosterone on the initiation of spermatogenesis was studied in the Indian House Lizard Hemidactylus during the non‐breeding season after pituitary ablation. Both ovine FSH and PMS initiated spermatogenesis leading to the formation of mature spermatozoa after 45 days while LH, HCG, or TP had no stimulatory effect on the testis. Synergistic action was not observed when FSH or PMS was injected in combination with LH, TP, or HCG as evidenced by the germ cell counts in the seminiferous tubules.The androgen‐dependent sexual segment of the kidney was also fully developed in the animals treated with FSH or PMS. These results indicate that the initiation of gametogenic and androgenic functions in the testis of the Indian house lizard are dependent on an FSH‐like protein.

Testosterone Propionate, a Bisexual Hormone in the American Chameleon

SummaryTestosterone propionate enlarges the Mullerian duct, keratinizes the cloaca and produces estrous behavior in Anolis. It also enlarges the epididymis, ductus deferens and sexual segment of the kidney, while producing male sex behavior. It has a gonado-tropic effect on the ovary but not on the testis.