Histology of the ovary of Chinchilla lanigera in captivity

Abstract

Chinchilla, the lanigera variety in particular, is one of the most valuable rodents in the fur industry. The chinchilla ovary is morphologically similar to that of other South American hystricognath rodents, especially as regards its anatomy and, to a lesser degree, its histology. The presence of numerous primary follicles throughout the annual cycle suggests that a few of them are recruited to initiate growth and differentiation during folliculogenesis. Primary follicles with two or more oocytes are common; this is not the case with follicles at more advanced stages, suggesting that they do not develop. Only one or two large corpora lutea (CL) and three to five small or accessories CL were observed but no corpora albicans. The presence of accessory CL may reflect the importance of continuous hormonal production to support prolonged gestation. Atretic CL were also present, showing signs of degeneration in luteal cells. The interstitial cells distributed throughout the cortex were the main histological feature shared with other species, as stated in previous reports. Antral atresia was observed in all sizes of antral follicles while basal atresia was confined exclusively to smaller follicles.