Polymorphisms Of MDFI And PHB2 Gene And Their Relationships With Productive Traits In Meat Rabbits

Because of limited conventional breeding techniques and increasing of meat demand every year, it is great significance to find major genes and genetic markers improving growth traits and meat quality. MyoD family inhibitor(MDFI) and Prohibitin2(PHB2) gene are two important genes related with production traits. In order to improve these traits, this study aimed at finding the SNPs in MDFI, PHB2 gene for molecular marker assisted selection. In this study, 339 meat rabbits including171 male rabbits and 168 female rabbits coming from Kangda strain 1 to strain 9, were selected and cultivated by Qingdao Kangda Ltd and Shandong Agricultural University to detect genetic variants by Mix-sequencing and PCR-SSCP and PCR-RFLP. SAS software were applied to analysis allelic frequency and relations between reproductive traits and different genotypes. The main results are as follows:(1)For MDFI gene, four mutations were found by primer designing for all sequences,Mix-sequencing and PCR-SSCP, which were G4010 A, T5874 C, A6400 G, C10732 T and each site had three genotypes. The result of χ2 test showed that G4010 A, A6400 G, C10732 T sites fitted Hardy-Weinberg equilibrium situation(P>0.05), while T5874 C site did not(P<0.05). In the male population, there was significant correlation between G4010 A and BW70, PH, WHP,DL, CL, SF, CA(P < 0.05). It was significant correlation between C10732 T with BW70,BL70, BC70(P < 0.05). In the female population, G4010 A and PH, G5874 A and IMF,A6400 G and CA, IMF had was significant relation(P < 0.05).(2) For PHB2 gene, four mutations were found by primer designing for all sequences,Mix-sequencing and PCR-SSCP, which were A678 C, C2653 T, A3004 G, G3048 A. A678 C site had three genotypes, the others had three genotypes. The result of χ2 test showed that None of the SNPs fit the H-W equilibrium situation(P<0.05). In the male population, A678 C and IMF, C2653 T and BW70, BC70, G3048 A and BW70, BC70 had significant correlation.In the female population, C2653 T and BW30, A3004 G and PH, CR, G3048 A and BW30 had significant correlation.(3)Different genotypes of MDFI gene and PHB2 gene expression in male rabbit showed:The expression levels of MDFI gene G4010 A, A6400 G, C10732 T sites have significant relation in dorsi longissimus muscle(P<0.05); The expression levels of MDFI gene G4010 A site have significant relation in back-leg muscle(P<0.05); The expression level of three different genotypes of PHB2 gene C2653 T has a significant relation in dorsi longissimusmuscle(P<0.05); The expression level of PHB2 gene every site has not a significant relation in back-leg muscle(P>0.05).(4)The results of MDFI showed that the levels of expression quantity at dorsi longissimus muscles are significantly different in the 30-day age individuals compared with the 60-day-age, 90-day-age and 120-day-age ones(P<0.05). Meanwhile, the levels of MDFI in the 160-day-age ones are significantly different compared with 60-day-age,90-day-age and120-day-age ones. The levels expression quantity of PHB2 at dorsi longissimus muscles,however, showed that the 30-day-age individuals and the 120-day-age individuals are significantly different compared with 60-day-age, 90-day-age and 160-day-age ones separately(P<0.05). As for the back-leg muscles, the levels of expression quantity of MDFI in 30-day-age, 60-day-age, 120-day-age individuals are significantly different compared with90-day-age and 160-day-age ones separately, besides, the levels of these three different age-groups are different from each other significantly. On the other hand, the levels of expression quantity of PHB2 in every different age-groups showed no difference.The study of MDFI and PHB2 gene detected eight mutations and analyzed their relationship with the meat rabbit’s production traits. The results show that these two genes could be or cooperate with major genes to affect meat rabbit’s growth traits and meat quality traits.