THE FUNCTION OF THE UTERO TUBAL JUNCTION AS SPERM RESERVOIR IN LLAMA

APICHELA, SILVANA A.; VALZ-GIANINET, JORGE; ROLDAN-OLARTE, EUGENIA M.; JIMÉNEZ-DÍAZ, MARÍA. A.; MICELI, DORA C.

Córdoba

Jornada; I REUNIÓN CONJUNTA DE SOCIEDADES DE BIOLOGÍA DE LA REPÚBLICA ARGENTINA; 2007

SOCIEDADES DE BIOLOGÍA DE LA REPÚBLICA ARGENTINA

In Lama glama ovulation occurs approximately 36 hours after mating, hereby it would be crucial to the fertilization success the maintenance of the sperm viability by the establishment of sperm reservoirs. We have studied the sperm reservoirs formation by sperm adhesion to the oviductal mucosa. The oviducts of adult lama females were obtained at 6, 18, 24, 28 and 34 hours post mating. Utero Tubal Junction (UTJ) and caudal isthmus were studied by light microscopy, electron microscopy and Scanning electron microscopy. Sperm were observed adhered to the UTJ epithelial cells at 6, 18, 24 and 28 h pos-mating. Sperm were trapped in a viscous substance and patchy distributed. This substance was absent in the oviducts of non mated females, suggesting a seminal origin. Later, the sperm would detach from the UTJ as they were not observed 34 hours after mating. No sperm were found adhered to the Isthmus cells in all the samples. The sperm interaction was also studied by in vitro methods, cocultivating sperm and oviductal vesicles (OV). The sperm binding index (BI) was calculated as the number of sperm adhered/0.5 mm2 of OV. The BI of UTJ was found to be higher than Isthmus (P<0.0001, t test). We conclude that the UTJ could form a sperm reservoir in lama, and seminal substances could be involved in its formation. The existence of a functional sperm reservoir in lama would explain why even 28 h after semen deposition the sperm fertilizing ability is maintained.