Gonocytes; neonate testicle
Keywords: gonocytes, testicle, lamb, neonate, seminiferous
This is a histological image of a testicle from a male lamb. It had been still born or aborted at term, the co-twin of a male pseudohermaphrodite. This sample was examined to determine how the testicle from the pseudohermaphrodite would differ from that of a normal animal.
It is possible that this animal was abnormal too but published data suggest otherwise.
Image size:1363 x 843px
Together with other interesting findings, this image shows gonocytes (G) centrally located in many seminiferous tubules. These cells are the precursors of spermatogonia and have also been called pre- or prospermatogonia. However, the most correct name for these cells remains a subject for debate. They are large diploid cells that migrate from the hind gut and populate the genital ridges in early embryos. Together with fibroblasts, gonocytes form the sex cords in the developing testicle. Apparently, many or most of the supporting cells seen at the periphery of the seminiferous tubules in this image, are Sertoli cells. Others are spermatogonia. Using high resolution microscopy to view osmium stained specimens, a similar situation in mice has been beautifully illustrated by Drumond A. L et al. (2001).
Gonocytes are relatively few in number at birth but as the male matures, they divide and form the majority of cells at the periphery of the tubules; the spermatogonia. In this image, cells thought to be Sertoli cells, spermatogonia and Leydig cells are marked with asterisks.
Other findings worthy of note are the eosinophil-like cells (non-PMN). The nature of these cells remains to be determined. Finally, nuclear remnants were common in the tubules and the interstitium. Their significance is also unknown.
References:
Culty, M. 2009 Gonocytes, the forgotten cells of the germ cell lineage. Birth Defects Res C Embryo Today. 87:1-26.
Culty, M, 2013 Gonocytes, from the Fifties to the Present: Is There a Reason to Change the Name? Biol. Reprod. 89:46, 1–6
Culty, M, 2013 Gonocytes, from the Fifties to the Present: Is There a Reason to Change the Name? Biol. Reprod. 89:46, 1–6
Drumond A. L., Meistrich, M. L. and Chiarini-Garcia, H. 2011 Spermatogonial morphology and kinetics during testis development in mice: a high-resolution light microscopy approach. Reproduction. 142:145-55.
Peters. H 1970. Migration of Gonocytes Into the Mammalian Gonad and Their Differentiation.Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 259: 91-101
Kluin, P.M. and de Rooij. 1981. A comparison between the morphology and cell kineticsof gonocytes and adult type undifferentiated
spermatogonia in the mouse. In J. Andrology. 4:475-493
Hutson J. M. et al. 2013 Germ cell development in the postnatal testis: the key to prevent malignancy in cryptorchidism? Frontiers in Endocrinology. (http://journal.frontiersin.org/Journal/10.3389/fendo.2012.00176/full)
