title: Prevalence of atretic corpora lutea in ovaries of bovine fetuses.
abstract: Both ovaries from 88 bovine fetuses in the fifth month or later of gestation were studied histologically to determine the prevalence, origin, and time of appearance of atretic corpora lutea (ACL). Ovaries from 36 (41%) fetuses had ACL; fetuses < 6 months of gestation did not have ACL. Six fetuses had more than 25 ACL, but there was no apparent relationship between fetal age and number of ACL. Formation of ACL involved disintegration of the stratum granulosum of secondary follicles, concomitant with proliferation and invasion by vascularized elements of the theca. Fully developed ACL consisted of a large primary oocyte surrounded by a prominent zona pellucida and encased in a well-vascularized, largely thecal, fibrocellular wall. They measured approximately 0.5 to 1.0 mm in diameter. Empty, collapsed zona pellucidas were seen in many of the degenerating ACL.
authors.affiliation: Department of Veterinary PathoBiology, College of Veterinary Medicine, University of Minnesota, St Paul 55108.
authors.forename: A F
authors.initials: AF
authors.lastname: Weber
authors.forename: V S
authors.initials: VS
authors.lastname: Cox
authors.forename: R E
authors.initials: RE
authors.lastname: Shope
authors.forename: T F
authors.initials: TF
authors.lastname: Fletcher
authors.forename: D M
authors.initials: DM
authors.lastname: Lee
mesh_terms: D000818:Animals; D002417:Cattle; D003338:Corpus Luteum / Q000166:cytology / Q000196:embryology*; D005314:Embryonic and Fetal Development; D005260:Female; D005496:Follicular Atresia; D005865:Gestational Age; D006080:Ovarian Follicle / Q000166:cytology / Q000196:embryology*; D010053:Ovary / Q000196:embryology*