Gonadotrophin Levels and Ovarian Development in the Neonatal Ewe Lamb

Tassell, Robin; Wa, Chamley; Jp, Kennedy

doi:10.1071/bi9780267

Cited by 36 publications

(23 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is not clear what triggers the development-no significant changes in circulating gonadotrophin levels have been detected in our animals (Tassell et al 1978), although Foster et al (1972) reported elevations of luteinizing hormone in the post-natal period. It has been claimed that early follicular growth is independent of gonadotrophic stimulation (Peters et al 1973).…”

Section: Introductionmentioning

confidence: 46%

Early Follicular Development and Atretic Changes in the Ovary of the Lamb? Fine Structure and Histochemistry

Tassell¹,

Jp²

1980

Aust. Jnl. Of Bio. Sci.

Self Cite

View full text Add to dashboard Cite

The fine structure of follicles was studied in ovaries from lambs up to 32 days old. Some animals received pregnant mare serum gonadotrophin prior to sampling. Follicles examined were in the primordial to early antral stages. The oocyte is described and changes associated with its development and the formation of the zona pellucida are recorded. Characteristics in which the lamb oocyte differed from those of other mammals included a greater prominence of smooth endoplasmic reticulum, the presence of microtubules, fine filaments in the peripheral parts and a large number of almost empty vacuoles. The latter were more numerous in oocytes which appeared to be degenerating, including some of those in primordial follicles. Granulosa cells had characteristics usually associated with protein secretion while some theca cells had large amounts of endoplasmic reticulum bearing few ribosomes. In early atresia changes were evident successively in the oocyte, granulosa and theca.There was a weak positive reaction for 3p-hydroxy-AS-steroid dehydrogenase in the theca of some vesicular follicles from both control lambs and lambs treated with pregnant mare serum gonadotrophin. Follicles showing signs of atresia were negative for this enzyme.

show abstract

Section: Introductionmentioning

confidence: 46%

Early Follicular Development and Atretic Changes in the Ovary of the Lamb? Fine Structure and Histochemistry

Tassell¹,

Jp²

1980

Aust. Jnl. Of Bio. Sci.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Tassell et al Follicles were classified as described by Trounson et al (1974) and Tassell et al (1978). Primordial, small and large growing (non-vesicular), and partially and fully formed vesicular follicles were counted.…”

Section: Methodsmentioning

confidence: 99%

Ovarian Follicles of New-born Merino Lambs from Genetic Lines which Differ in Fecundity

Rj¹,

Jp²,

Bm³

et al. 1983

Aust. Jnl. Of Bio. Sci.

Self Cite

View full text Add to dashboard Cite

Ovaries were obtained from 78 new-born lambs (12 singletons, 25 twins, 28 triplets, 10 quadruplets and 3 quintuplets) from flocks selected for (T902, T903 and Booroola) or against (0) multiple births. Sections of the ovaries were examined with a projection microscope and the numbers of all types of follicles were estimated. There were no differences between genetic lines in the number of primordial follicles, after adjustment for litter size and sire; however, there were significantly more of these follicles in single-born lambs than in lambs born in litters of two or more within genetic lines. The number of vesicular follicles was lower in Booroola than in 0 lambs.

show abstract

“…Experiments with ovariectomized ewe lambs established that the ovary also influences uterine growth and endometrial gland morphogenesis after PND 14 (Carpenter et al 2003a). The neonatal ovine ovary contains both the preantral and antral ovarian follicles at birth, which decline on PND 14, increase to maximum numbers on PND 28, remain high from PNDs 42 to 56, and decline thereafter (Kennedy et al 1974, Tassell et al 1978. These changes in the ovarian follicular dynamics are temporally correlated with the ontogeny of endometrial gland development in the neonatal ewe (Wiley et al 1987, Taylor et al 2001.…”

Section: Introductionmentioning

confidence: 88%

Postnatal uterine development in Inverdale ewe lambs

Hayashi

O’Connell²,

Juengel³

et al. 2008

Reproduction

View full text Add to dashboard Cite

Postnatal development of the uterus involves, particularly, development of uterine glands. Studies with ovariectomized ewe lambs demonstrated a role for ovaries in uterine growth and endometrial gland development between postnatal days (PNDs) 14 and 56. The uterotrophic ovarian factor(s) is presumably derived from the large numbers of growing follicles in the neonatal ovary present after PND 14. The Inverdale gene mutation (FecXI) results in an increased ovulation rate in heterozygous ewes; however, homozygous ewes (II) are infertile and have 'streak' ovaries that lack normal developing of preantral and antral follicles. Uteri were obtained on PND 56 to determine whether postnatal uterine development differs between wild-type (CC) and II Inverdale ewes. When compared with wild-type ewes, uterine weight of II ewes was 52% lower, and uterine horn length tended to be shorter, resulting in a 68% reduction in uterine weight:length ratio in II ewes. Histomorphometrical analyses determined that endometria and myometria of II ewes were thinner and intercaruncular endometrium contained 38% fewer endometrial glands. Concentrations of estradiol in the neonatal ewes were low and not different between CC and II ewes, but II ewes had lower concentrations of testosterone and inhibin-a between PNDs 14 and 56. Receptors for androgen and activin were detected in the neonatal uteri of both CC and II ewes. These results support the concept that developing preantral and/or antral follicles of the ovary secrete uterotrophic factors, perhaps testosterone or inhibin-a, that acts in an endocrine manner to stimulate uterine growth and endometrial gland development in the neonatal ewes. Reproduction (2008) 135 357-365

show abstract

Gonadotrophin Levels and Ovarian Development in the Neonatal Ewe Lamb

Cited by 36 publications

References 13 publications

Early Follicular Development and Atretic Changes in the Ovary of the Lamb? Fine Structure and Histochemistry

Early Follicular Development and Atretic Changes in the Ovary of the Lamb? Fine Structure and Histochemistry

Ovarian Follicles of New-born Merino Lambs from Genetic Lines which Differ in Fecundity

Postnatal uterine development in Inverdale ewe lambs

Contact Info

Product

Resources

About