Development of the Mammalian Testis

Gier, H. T.; Marion, G. B.

doi:10.1016/b978-0-12-386601-1.50007-x

Cited by 47 publications

(29 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The different conclusions could be due to the different source for control data. Our previous report compared the findings in the xenografts to reports in the literature that the first elongated spermatids and sperm in sheep appeared between 5 and 6 months after birth (Gier & Marion 1970). However, elongated spermatids can be found, when assessed histologically, in 12-week-old Suffolk rams as observed in the present study.…”

Section: Discussioncontrasting

confidence: 31%

Xenografting of sheep testis tissue and isolated cells as a model for preservation of genetic material from endangered ungulates

Arregui

Rathi²,

Megee³

et al. 2008

Reproduction

View full text Add to dashboard Cite

Recovery of germ cells could be an option for preservation of the genetic pool of endangered animals. In immature males, xenografting of testis tissue provides the opportunity to recover sperm from these animals. In adult animals, xenografting has been less successful, but de novo morphogenesis of functional testis tissue from dissociated testis cells could be an alternative. To assess the potential use of these techniques in endangered bovid species, the domestic sheep was used as a model. Testes from 2-week-old lambs were grafted as tissue fragments or cell suspensions into nude mice. Grafts were recovered at 4, 8, 12 and 16 weeks post grafting. For isolated cells, two additional time points at 35 and 40 weeks after grafting were added. In addition, to analyse the possible effect of social stress among mice within a group on the development of the grafts, testis tissue grafts were recovered 13 weeks post grafting from mice housed individually and in groups. Complete spermatogenesis occurred in sheep testis xenografts at 12 weeks, similar to the situation in situ. Isolated sheep testis cells were able to reorganize and form functional testicular tissue de novo. Housing mice individually or in groups did not have any effect on the development of xenografts. Xenografting of testis tissue might be useful to obtain sperm from immature endangered ungulates that die prematurely. Testis tissue de novo morphogenesis from isolated cells could open interesting options to recover germ cells from mature males with impaired spermatogenesis. Reproduction (2008) 136 85-93

show abstract

Section: Discussioncontrasting

confidence: 31%

Xenografting of sheep testis tissue and isolated cells as a model for preservation of genetic material from endangered ungulates

Arregui

Rathi²,

Megee³

et al. 2008

Reproduction

View full text Add to dashboard Cite

show abstract

“…The left gonad was related ventromedially with the stomach, while the right one was related to the coils of intestine. This was in close association with the observations of Gier & Marion (1970) who observed the genital ridge on 28 th day of gestation in embryos of ox. On 42 nd day (II group) of gestation the genital ridge developed into a cylindrical structure, the testis with rounded extremities, situated in the middle of the ventromedial aspect of the mesonephros (Fig.…”

Section: Resultssupporting

confidence: 61%

Anatomical Study on the Descent of Testis in Prenatal Goat (Capra hircus)

2011

View full text Add to dashboard Cite

SUMMARY:A study was conducted on 70 embryo/ foetii of goats to observe the descent of testis. These foetii were grouped into I (0-30 days), II (31-60 days), III (61-90 days), IV (91-120days) and V (121 days up to term, having 14 embryos/ foetii in each group. The genital ridge was observed at 1.2cm CRL (23 day) on the ventromedial aspect of mesonephros. At 42 nd day, the genital ridge developed into cylindrical structure, the testis, located in the middle of metanephros. The abdominal migration was completed upto 88 th day. The testes were situated in the inguinal canal from 89 th to 95 th day. From 90 th day onward, scrotal migration had been observed, however the testis did not reach the base of the scrotum up to term. During the descent of testis, a peritoneal fold detached from the caudal end of the gonad and extended up-to the abdominal floor on 42 nd day, known as gubernaculum. In the initial stages of pregnancy it was thin, whitish, jelly like. On 70 th day it was enveloped by processus vaginalis. In group V, it became hardened, longer and cord like.

show abstract

“…Arey (1966) observed a layer of tissue, fibrous capsule or tunica albuginea in between the germinal epithelium and testis cords at 15mm CRL in human embryos. Gier & Marion (1970) observed the appearance of the tunica albuginea at 30, 33 and 41th day of gestation in horse, dog and ox, respectively. Singh et al observed a distinct tunica albuginia at 33.5mm CRL stage (47 days) in goat foeti.…”

Section: Testicular Capsule (Tunica Albuginea) At 44mentioning

confidence: 95%

Histological and Histochemical Studies on the Prenatal Development of Testis in Goat (Capra hircus)

2012

View full text Add to dashboard Cite

studies on the prenatal development of testis in goat (Capra hircus). Int. J. Morphol., 30(4):1408-1421, 2012. SUMMARY:The study has been conducted on the prenatal development of testis on 70 goat embryo/foeti, categorized into group-I (0-30 days), Group-II (31-60 days), Group-III (61-90 days), Group-IV (91-120 days) and group V (121days-till birth), having 14 embryos/ foeti in each group. The genital ridge was observed at 23 days of gestation. It contained an accumulation of mesenchymal cells, immature RBC's, differentiating fibroblasts and primordial germ cells. The formation of sex cords was evidenced on 44 th day of gestation. It contained small mesenchymal cells and large cells arranged in a chain like manner. The convolution of the sex cords started between 61-90 days of gestation, which increased with the increase in the gestation period and at 125 day of gestation few sex cords attained the form of reverse question mark. The sustentocytes (Sertoli cells) were observed among the small cells of sex cords at 56 th day of gestation. The tunica albuginia appeared just beneath the germinal epithelium at 44 th day of gestation. It consisted of 2-4 layers of mesenchymal cells, fibroblasts and small capillaries. The thickness of tunica albuginia increased with the increase in the age of foetus and between 61-90 days of gestation, the outer thick fibrous and inner thin vascular layer could be demarcated separately. Few mesenchymal cells start differentiating into interstititial endocrine cells (Leydig cells) located in the interstitial spaces at 44 th day of gestation.

show abstract

Development of the Mammalian Testis

Cited by 47 publications

References 31 publications

Xenografting of sheep testis tissue and isolated cells as a model for preservation of genetic material from endangered ungulates

Xenografting of sheep testis tissue and isolated cells as a model for preservation of genetic material from endangered ungulates

Anatomical Study on the Descent of Testis in Prenatal Goat (Capra hircus)

Histological and Histochemical Studies on the Prenatal Development of Testis in Goat (Capra hircus)

Contact Info

Product

Resources

About