ARGAÑARAZ Martin Eduardo
congresos y reuniones científicas
Regulation of Lefty2 in the oviduct of cyclic, pregnant and pseudopregnant rats
MARTIN E. ARGAÑARAZ; PABLO A. VALDECANTOS; DORA C. MICELI
Congreso; 16 th International Congress on Animal Reproduction; 2008
Spanish Society of Animal Reproduction, European Society for Domestic Animal Reprod. & European Vet. Soc. of Small Animal Reprod.
Regulation of Lefty2 in the oviduct of cyclic, pregnant, and pseudopregnant rats. Argañaraz, ME1, Valdecantos, PA2, Miceli, DC1* 1Instituto Superior de Investigaciones Biológicas, CONICET, Argentina; 2Facultad de Bioquímica,Cátedra de Biología Celular, Universidad Nacional de Tucumán, Argentina Transforming growth factor beta superfamily members are closely associated with tissue remodeling events and reproductive processes, being involved in the embryo development and in the maternalembryo cross-talk. Moreover, transforming growth factor beta and their receptors were found in the preimplantation embryo and the reproductive tract (oviduct and uterus). Lefty2 an unusual member of this family has been implicated in the regulation of other transforming growth factor beta members such as nodal, activin, bone morphogenic proteins and transforming growth factor beta 1 via cryto co-receptors and by an antagonic mechanism. To date, the presence and regulation of Lefty2 in the rat oviduct have not been described yet. The aim of the present study was to investigate the expression of Lefty2 and its co-receptor (crypto) in the oviduct. RNA; oviductal proteins and tissues were collected from cyclic non-pregnant, pregnant, and hormonally-induced pseudopregnant rats. Lefty is a pre-proprotein of 42 kDa that is proteolytic activated to a mature form of 26 kDa. Lefty2 proteins were detected by western blots in the oviduct of cyclic, pregnant, and pseudopregnant rats but were not influenced by the estrous cycle. During early pregnancy, Lefty2 mature form was significantly higher at day 4 (when the embryo is still in the oviduct) and then it was gradually decreased while the pre-proprotein had not significant modifications. During pseudopregnancy, both form of Lefty2 protein were found at very low levels, without variations. Crypto transcripts, analyzed by semi-quantitative RT-PCR, were detected in the oviduct in the three studied conditions. Crypto expression levels were increased at day 4 of pregnancy, as we have reported for the lefty2 protein. Neither the estrous cycle nor the pseudopregnancy showed variation in the crypto gene expression pattern. These results suggest that Lefty2 and crypto are present in the rat oviduct during pregnancy; that Lefty2 could act along a paracrine pathway by binding to specific receptors on oviductal cells and that their expression could be independent of steroid regulation. The secretion of Lefty2 could be important for the embryo maintenance during its pass through the oviduct.