Studies On Inheritance And Gene Effect Of Intramuscular Fat Trait In Chicks

The objectives of this research were to detect the phenotypic inheritance and gene effect of H-FABP on breast muscle intramuscular fat trait, lipid deposit, meat quality, growth, carcass, body measurement, shank color and feather color using a segregation population of GUSHI-ANKA half-sib family resource design. Information of major gene, gene number, additive effect, molecular marker was developed and evaluated based on data of phenotype, pedigree and molecular identification of intramuscular fat trait. The results were as follows.Phenotypic inheritance of intramuscular fat trait. This experimental population included 860 segregation progenies derived from seven families. The mean of intramuscular fat content was 2.62%, with the highest content 4.96%, the lowest content 0.36% and the coefficient of variability was 0.33 calculated from 789 valid records statistically. The intramuscular fat contents of F₂ generation from GUSHI grandmothers were lightly higher than that from ANKA grandmothers, but there were no differences between them (P>0.05) . There were no significant differences among male parents (P>0.05) , whereas varieties were significant among female parents(P<0.05), such as A, B, C, G family, indicating not only the consistence of trait researched from the same male parents, but also the variance between different female parents. Between sexes in generation F₂, the contents of intramuscular fat were not different significantly (P>0.05) .Inheritance analysis of H-FABP gene. A transversion c? a at 1174th bp in the second intron of H-FABP gene was detected using PCR-SSCP method. Two alleles, designated as M and N, constructing three genotypes, were distributed with Hard-Weinberg equilibrium among F2 population. The frequency of N, a favorable allele, was 0.422, and the frequencies of NN, heterozygosity, Genetic polymorphism information content were 0.175, 0.488, 0.369, respectively, with intermediated Genetic polymorphism information content. The genotypes, detected from 696 of total experimental population, influenced significantly intramuscular fat content(P<0.05), and intramuscular fat content of chickens carrying NN was higher than that of MN(P<0.05)and MM (P<0.01) . Genotypes also influenced significantly intramuscular fat content of original cross group(P<0.05), but not influenced significantly reciprocal cross group (P>0.05) . In every family, the genotypic effect was not consistent, and intramuscular fat content significantly different only in A family, E family(P<0.05)and B family (P<0.01) , whereas not significant in families else ( P>0.05 ) .