Study of the Expression of Progesterone Receptors in the Endometrium of Ewes with Normal and Supplementary Diet

The influence of nutrition on reproduction in sheep is complex and the reported results are variable. Low nutritional programs can cause a reduction in the sensitivity of the endometrium to progesterone which affects morphofunctional development of the endometrium in early stages of pregnancy and therefore is in direct expense of the survival of the embryo. Progesterone and estrogens act through specific intracellular receptors that mediate its physiological effect. Therefore the level of expression of these receptors is essential for the hormonal effect. The aim of this study was to analyze the expression of progesterone receptors (PR) and estrogen (ER) in the endometrium of sheep supplemented diet cycle and fed normal diet. The expression of the receptor protein and the transcript of both receptors was detected by immunohistochemistry and RT-PCR Real Time. The results show immunohistochemical expression against both receptors in caruncular and glandular areas, highlighting an intense immunoreaction in the nucleus of stromal cells and glandular epithelium. Were detected increased expression of the transcript of both receptors in sheep fed on the supplement that did not receive food supplement. We discuss the possible use of this information for applications in breeding programs in sheep breeding.