Cloning And RFLP Of Fragment From Exon 6 To Exon 8 Of HMGR Gene And Its Association With Important Economic Traits In Geese

3-hydroxy-3-methylglutaric acid coenzyme A reductase(HMGR) is the crucial rate-limiting enzyme relating to cholesterol metabolic process and cholesterol synthesis. The genome DNA was extracted from the blood of hybridization F₁ of Wanxi-White goose and Sichuan-White goose.A pair of primers were designed based on the conservative regions in exon 6 for forward and exon 8 for reverse according to HMGR gene sequences in human,chicken and pig.Forty important economic traits of 101 geese from F₁ population were detected.The restriction fragment length polymerphism(RFLP) of the region from exon 6 to 8 of HMGR gene was identified by PCR-RFLP with Pistâ… ,Hindâ…¢, Hinfâ… and Scrfâ… ,and different genotype association with goose important economic traits was studied.1.The region from exon 6 to 8 of HMGR gene was cloned and sequensed and the fragment length of the region was 1159 bp in which the lengths of exon 6,exon7 and exon8 were 104bp,117bp and 103bp,and the lengths of intron 6 and intron 7 were 418bp and 417bp respectively.The sequence has been submitted to the NCBI GenBank(Accession number: EU753857).2.The RFLPs were detected by PCR-RFLP with Hinfâ… and Scrfâ… ,and no RFLP with Pistâ… and Hindâ…¢.Allele A and B were identified by Hinfâ… ,and formed AA,AB and BB genotypes,the genotypic frequencies of which were 0.2178,0.1782 and 0.6040 respectively,the frequencies of allele A and B were 0.3069 and 0.6931 respectively.The frequencies of allele C and D with Scrfâ… formed CC,CD and DD genotypes were 0.6584 and 0.3416 respectively,the genotypic frequencies of which were 0.5050,0.3069 and 0.1881 respectively.3.The sequenced results indicated that the mutation of nucleotide C→T and C→G at position 48 and 254 in the intron 7 caused the change of allele D→C and A→B respectively.4.RFLP association with goose important economic traits was analyzed.The results indicated that breast fat weight and chest muscle weight were two key traits in carcass trait influenced by different genotype.DD genotype had significantly effect(P＜0.01) on an increase of breast fat weight(12.14%) and on a decrease of chest muscle weight(12.80%), but the effects of AA genotype were significant(P＜0.01) on increasing chest muscle weight(9.18%) and on decreasing breast fat weight(9.88%).On carcass trait ratio, DDgenetype had significantly effect(P＜0.01) on increasing breast fat percentage(13.19%) and on decreasing chest muscle percentage(-14.77%).On feather-down trait,CC genotype had significantly effect(P＜0.01) on increasing feather-down weight and feather-down percentage(12.39%and 11.38%),AB genotype had effect(P＜0.05) on increasing 1000 downs weight(11.15%),and CD genotype had effect on decreasing feather-down weight(-8.50%,P＜0.01),feather-down percentage (-8.16%,P＜0.05) and 1000 downs weight(-8.99%,P＜0.05).On meat quality trait,CC genotype had significantly effect(P＜0.01) on increasing leg muscle water loss percentage and chest muscle(11.31%and 8.38%);DD genotype had significantly effect(P＜0.01) on decreasing leg muscle water loss percentage(-14.90%); AB genotype had significantly effect(P＜0.05) on decreasing crude fat of chest muscle(-9.36%) and on increasing crude fat of chest muscle(19.32%,p＜0.01);CD genotype had significantly effect(P＜0.01) on increasing crude fat of chest muscle (10.28%);and BB genotype had significantly effect(P＜0.05) on decreasing leg muscle water loss percentage(-8.77%).