Estrous cycle in laboratory and field conditions in two species of South American Muridae (Akodon azarae & Calomys laucha)

P. CETICA, M.C. ANDRÉS, M. BUSCH AND M.S. MERANI

MASTOZOOLOGíA NEOTROPICAL

MAGRAF-CRICYT

Año: 1996 vol. 3 p. 153 - 159

0327-9383

Many South American murids are reservoirs of etiologic agents of endemic diseases that are transmitted to man. The study of their reproductive physiology is essential for the knowledge of these diseases. We studied the changes in the vaginal cell morphology to determine the characteristics of the estrous cycle in Akodon azarae and Calomys laucha in laboratory conditions. We used this information to establish in these species the distribution of the estrous cycle throughout the seasons during a year in field conditions. The length of the cycle most frequently observed was 6 and 7 days for A. azarae and C. laucha respectively. In both species vaginal smears were studied during the estrous cycle. The changes in the vaginal smears were also studied during gestation in C. laucha. Field data showed that there is not a complete interruption of estrous cyclicity in these rodents in winter, however pregnant females (as determined by abdominal palpation) were not captured in this season.