Estudo sobre a reprodução de ovinos da raça somalis brasileira: histomorfometria epididimária, expressão gênica e proteica no aparelho reprodutor.

Abstract

The Somalis Brasileira breed is one of the most rustic sheep of the Northeast, being very adapted to the semi-arid and extensive breeding systems, based on native pasture. Therefore, this breed, as well as the others described, represent unique and extremely important genotypes to guarantee the variability of herds in production systems, formation of new breeds or crosses with exotic animals. Despite the aptitude and differentiated adaptability of the Brazilian Somalis sheep, few works are found in the literature on these animals. Therefore, the present study was conducted with the purpose of evaluating aspects of the epididymis, gene expression and proteomics of tissues of the reproductive apparatus of sheep of this breed. Animals with 150 days of age were slaughtered (according to norms of the Ministry of Agriculture) and organs collected for analysis of RNA extraction in testis, epididymis, vesicular and bulb-urethral glands, and epididymal histomorphometry. Expression of the genes was assessed by RT-PCR, using the GAPDH gene as a reference. Protein was also extracted from epididymal tissue samples for identification by mass spectrometry (ESI-Q-ToF). Data thus obtained were analyzed with the protein annotation application (STRAP) and the potential interactions of specific proteins, with the application STRING 9.05. The expression of clusterin was detected in all tissues analyzed, but the head (Ep2) and body (Ep5) regions of the epididymis presented the highest expressions (p <0.05). The expression of mRNA for osteopontin was localized in all tissues tested, but the expression in the seminal vesicles was higher than in the other organs (p <0.05). Levels of mRNA for osteopontin did not differ in the regions of the epididymis, testis and bulb-urethral glands (p> 0.05). Expression of prostaglandin D-synthetase (PGDS) mRNA was detected in the testes and all segments of the epididymis, with no differences between them (p> 0.05). However, it was not possible to detect expression levels of this gene in the accessory sex glands. The results obtained in the histological analysis of the 8 epididymal segments in Brazilian Somali sheep showed the presence of several cell types in the epithelium, such as main, apical, basal and halo cells. The main, basal and halo cells were observed in all segments of the epididymis and apical cells were not observed in the tail of the epididymis. The volumetric proportion of the regions showed a higher percentage of epithelium in the proximal head, distal head and body (Ep6), and the lower count was shown in the body (Ep5). The connective tissue count was higher in the same segment (Ep5) and without significant differences along the epididymal segments in general. The lamina propria count showed few alterations in the regions of the epididymis and the lumen without spermatozoa was visibly larger in the proximal head, whereas in the region of the head and body of the epididymis there was a large percentage of lumen with spermatozoa.