A first approach to determining luteinizing hormone levels to study reproductive strategies in the pichi (Zaedyus pichiy, Mammalia, Xenarthra), a threatened armadillo

ACTIS ESTEBAN; VALDEZ, SUSANA R; CUELLO-CARRIÓN, F DARÍO; JAHN GRACIELA A; SUPERINA MARIELLA

San Luis

Congreso; Reunión Anual de la Sociedad de Biología de Cuyo; 2012

Sociedad de Biología de Cuyo

Reproductive strategies vary considerably among species, but most studies have focused on only 0.3% of all known mammalian species. Because the survival of a species is inevitably tied to its ability to reproduce, data on its reproductive cycle are paramount when deciding how best to manage it. The pichi Zaedyus pichiy is a threatened, heavily poached small armadillo native to Argentina and Chile. This seasonal breeder produces one yearly litter of 1–2 offspring. Based on the absence of regular estrous cycles and corpora lutea in non-pregnant females, and the observation that pichis mate immediately after pairing, we hypothesized that pichis are induced ovulators. As a first step, we collected hypophyses of 4 dead pichis (roadkills or death by natural causes) and confirmed through Western Blot and immunohistochemistry that a commercial polyclonal anti-luteinizing hormone antibody recognized pichi LH, which we then used to develop a heterologous RIA. We collected blood samples from captive females before and after pairing and quantified the concentration of LH. Hormone levels were similar pre- and post-mating, as well as in females that were not paired. This does, however, not exclude the possibility that pichis are induced ovulators, but may be related to the timing of blood sampling. No data are available on the interval between mating and the timing of the pre-ovulatory LH peak in pichis, which in other species varies between 6 and 72 hours. Additional experiments with varying intervals between mating and blood extraction are being carried out.