Numerous differences in reproductive physiology are known among animals of Zebu (Bos indicus) and European breeds (Bos taurus) such as: the age of puberty, duration of estrus, number of subordinate follicles and the measurement of the dominant follicle at deviation, the ovulatory follicle and the corpus luteum. Reports indicate that female B. indicus cattle have a higher number of follicles per wave than females B. taurus and this follicle numeric proportion remains constant until the age of 8-10 years of the animal. Thus, those animals are labeled as of high and low follicular population in both breeds. Authors state that the follicular population is related to animal fertility and is greatly influenced by the activity of FSH, estradiol (E2) and androgens. However, little is known about the oviduct molecular profile on the follicular population variability between breeds in the bovine specie. The oviduct has an essential role in mammals' reproductive physiology, providing a microenvironment for oocyte maturation, sperm capacitation, fertilization, gametes transportation and early embryo development. It is known that the ciliary beat frequency, responsible for the gamete transportation, undergoes changes controlled by the amount of E2 and P4, and so is the oviduct contraction and relaxation, which are influenced by the LH, E2, and P4, hormones directly related with the profile of follicular population. Therefore, this study aims to evaluate the influence of the breed, Nelore (Bos indicus) and Aberdeen Angus (Bos taurus), the ovarian follicular population and the antimere related to ovulation (ipsilateral and contralateral oviduct) on the molecular profile of genes involved in the interaction with sperm (annexins), contractility of the oviduct (vascular endothelial growth factor; VEGF system), lipid metabolism, enzymes and proteins from cell interaction in the three segments of the oviduct (infundibulum, ampulla and isthmus) using the TaqMan® Low Density Array (TLDA system) during the initial period after ovulation. In summary, the results obtained in this approach may maximize the understanding of the influence of ovarian follicular population in these two breeds and on the various reproductive events in cows, providing newer information to the running work of our research group ("Comparative study of follicular population of Nelore and Angus cows, "Auxílio Regular" funded by FAPESP; 2011/50964-0).
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