UTILIZATION OF MOLECULAR MARKERS TO DETECT SOME GENES AND MUTATIONS AFFECTING ECONOMIC TRAITS IN EGYPTIAN SHEEP BREEDS
Creators: name: Saleh, Ahmed
Publisher: name: figshare
Year: 2020
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: FOS: Biological sciences

description: Improving sheep production is strongly based on animal genetics as most of the quantitative economic traits have polygenetic nature. Molecular tools provide valuable knowledge that could contribute to enriching the information about genes underlying economical traits. In view of the lack of enough investigations about the genetic polymorphisms of production genes in Egyptian sheep breeds, the aims of this work were to study the differentiation ''polymorphisms'' in IGFBP-3 and GH genes and their association with several growth traits. The important role of IGFBP-3 and GH genes in growth performance is well recognized, then their polymorphisms and interaction with the growth trait should be the subject of further research. According to the current study, the probable presence of an association between differentiation in genotypes of GH gene and growth performance also, weight at birth, weaning and six-month could be candidate markers in sheep breeding program for improvement of growth rates. In this study, Digestion of 654 bp for IGFBP-3/HaeIII yielded only one restriction pattern of 8 fragments in all animal groups revealing the absence of polymorphism also, DNA sequencing confirmed that. While, sequencing analysis of the ampliﬁed fragment of GH gene revealed polymorphism in nucleotide sequencing, and the amino acid sequences for GH gene of Rahmani were different from those of other breeds in 4 amino acids, while, each of Rahmani X Barki cross and Ossimi amino acid sequences were different in 3 amino acids. The genetic differences in GH gene coincided with differences in birth, weaning and six-month weights of the breeds under study. Thus, the current results suggest that body weights and growth performance of tested sheep breeds at different stages of growth are statistically affected by GH gene which could be considered as a candidate gene for growth in breeding programs. On the other side, the prolificacy genotypes at genes BMPR-1B, GDF-9 and BMP-15 were found so far in the genomes of many prolific breeds throughout the world. More research on these genes in Egyptian sheep breeds is required for detection of more polymorphisms, comparisons of gene sequencing and tracing the evolutionary relatedness for gene sights among sheep breeds. More investigations to confirm and apply those advantages are necessary. Also, detection of useful genes or mutations as a primary step before transferring them to another breed, composite, or line either by crossing or even by more sophisticated techniques should help achieving the betters of their presence and avoid the damage that they may cause if compiled wrongly. in this study, the results revealed that all breeds did not carry Fec-B mutation. On the other side, the mutations of FecX<sup>G</sup>, and Fec-G<sup>H</sup> were detected in Rahmani, and Rahmani X Barki cross which is associated with the high twinning rate/litter size of Rahmani (1.28) and Rahmani X Barki cross (1.22). While, the average litter size for other breeds had almost a constant values rate over six parities, ranging between 1.00 and 1.04.