Studies on the fetal development of the gubernaculum in cetacea

The Anatomical Record
P van der Schoot

Abstract

Adult cetacean males, like non-mammalian vertebrates and other testicond mammals, have intra-abdominal testes. There is no evidence of a processus vaginalis in them. Testicondia in cetaceans is considered secondary as they are judged, evolutionarily, the descendants of terrestrial mammals (ungulates) with testis descent. A possible argument in support of the latter contention would be that cetacean fetuses develop gubernacula which are the primordia of the processus vaginalis and other structures associated with testis descent in other placental mammals. The present study intended to analyse cetacean fetuses in this respect. Serial sections of 25 fetuses (total body length between 39.5 and 160 mm) of 4 cetacean species (Delphinus delphis, Phocoena phocoena, Eschrichtius robustus, Physeter catodon) were examined with special attention to the presence or absence of structures homologous to the gubernaculum of other placental mammals (rats and humans). Gubernacular primordia were observed in fetuses from about the time of onset of sexual differentiation. Their shape and anatomical relationship with the surrounding structures were similar as those in mammals with testis descent. The gubernaculum in males developed into a large mass...Continue Reading

References

Apr 1, 1979·Fertility and Sterility·M T Frankenhuis, C J Wensing
Aug 23, 1990·Journal of Theoretical Biology·S Freeman
Jan 1, 1988·Hormone Research·C J Wensing
Dec 1, 1970·Journal of Reproduction and Fertility·J M Cummins, T D Glover
Jun 1, 1967·Journal of Reproduction and Fertility·R V ShortM F Hay
Jun 1, 1967·Journal of Reproduction and Fertility·M M Bryden
Apr 1, 1981·International Journal of Andrology·B KarpeE M Ritzén
Dec 30, 1982·The Journal of Experimental Zoology·J M BedfordG L Dryden
Jan 1, 1994·Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology·S A RommelW A Friedl
Jun 1, 1993·Biology of Reproduction·F H Bronson, P D Heideman
Dec 1, 1993·The Anatomical Record·S A RommelW A McLellan
Nov 3, 1945·British Medical Journal·A W Badenoch

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