Testosterone cycle and regulation of reproductive events in the lizard Phymaturus punae (Liolaemidae) from the highlands of the Andes, Argentina.

BORETTO JM; FORNES MW; JAHN GA; ACOSTA JC; IBARGÜENGOYTÍA NR

JOURNAL OF HERPETOLOGY

SOC STUDY AMPHIBIANS REPTILES

Lugar: Salt Lake City; Año: 2014 vol. 48 p. 172 - 180

0022-1511

The genus Phymaturus, entirely viviparous and mostly herbivorous, inhabits the cold and harsh environments of the Andean highlands of Argentina and Chile, and the Patagonian steppe of Argentina. Phymaturus punae is a vulnerable lizard endemic to the Biosphere Reserve San Guillermo (National Park and Provincial Reserve) in San Juan (Argentina) that inhabits high altitudes of 3,100 to 4,200 m. The reproductive cycles of males and females of P. punae have been described previously. Males perform a prenuptial and annual cycle, and females reproduce once every two years. As a consequence, the adjustment in the timing of males to the reproductive cycles of females must be very precise to ensure reproductive success. We elucidate the time of mating and the asynchrony of males and females reproductive events in P. punae based on endocrine and ultrastructural studies. Present hormonal results support the idea that copulation in P. punae occurs at the end of the activity season. Ultrastructural features observed in Sertoli and Leydig cells indicate that both types of cells have the potential to synthesize steroid hormones, to support the spermatogenic cycle and the mating period, respectively. In P. punae the cases of temporal asynchrony in steroid activity, suggest that this mechanism must be important to start the spermatogenesis in spring, supported by the steroid activity of Sertoli cells, since Leydig cells are inactive. Nevertheless the asynchronic steroid mechanism seems to be more necessary in Phymaturus species with continuous or postnuptial cycles, than in species with prenuptial cycles, like P. punae.