title: Ovarian features of the wild collared peccary (Tayassu tajacu) from the northeastern Peruvian Amazon.
abstract: In this study, the ovaries of 27 wild collared peccaries (Tayassu tajacu) from the Amazonian region of northeastern Peru were examined macroscopically and microscopically, and expression of major steroidogenic enzymes was detected by immunohistochemistry. Our observations suggest a mean ovulation rate of 2.3 +/- 0.6 follicles and a low rate of reproductive wastage (0.4 +/- 0.6 oocytes or embryos per pregnancy). The collared peccary seems to exhibit follicular waves involving the synchronous growth of a cohort of follicles, several of which seem to attain selection. The presence of antral follicles in pregnant females suggests that follicular turnover continues during pregnancy. In cyclic animals, corpora lutea were characterised by the presence of distinct large and small luteal cell populations. The luteal volume in pregnant females was larger than that recorded for non-pregnant females. Through immunohistochemistry, it was observed that luteal cells from active corpora lutea exhibit intensive 3beta-HSD expression in advanced stages of pregnancy. This suggests that the corpora lutea seems to remain steroidogenically active throughout pregnancy and likely contribute to progesterone production during pregnancy.
authors.affiliation: Department of Animal Health and Anatomy, Faculty of Veterinary, Autonomous University of Barcelona, Bellaterra, E-08193 Barcelona, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Mayor
authors.forename: Mar
authors.initials: M
authors.lastname: Fenech
authors.forename: Richard E
authors.initials: RE
authors.lastname: Bodmer
authors.forename: Manel
authors.initials: M
authors.lastname: Lopez-Bejar
mesh_terms: D015096:3-Hydroxysteroid Dehydrogenases / Q000378:metabolism; D000818:Animals; D000835:Animals, Wild; D001141:Aromatase / Q000378:metabolism; D001188:Artiodactyla / Q000033:anatomy & histology* / Q000502:physiology*; D003338:Corpus Luteum / Q000166:cytology; D030762:Estrous Cycle / Q000502:physiology; D005260:Female; D006080:Ovarian Follicle / Q000033:anatomy & histology / Q000648:ultrastructure; D010053:Ovary / Q000033:anatomy & histology* / Q000201:enzymology / Q000648:ultrastructure; D010060:Ovulation / Q000502:physiology; D010568:Peru; D011247:Pregnancy; D013254:Steroid 17-alpha-Hydroxylase / Q000378:metabolism; D013799:Theca Cells / Q000166:cytology
chemical_list: D015096:3-Hydroxysteroid Dehydrogenases; D001141:Aromatase; D013254:Steroid 17-alpha-Hydroxylase