Analysis About The Genetic Mutation Of Nucb And Gad Genes And Their Effect With Growth Traits In Cattl

Genetic variations of energy homeostasis related genes (NUCB2, NUCB1, GAD1, GAD2,) were detected by PCR-RFLP, PCR-SSCP and DNA sequencing techniques in 1036 individuals of seven populations (Nanyang, Qinchuan, Jiaxian Red cattle, Hasak, Angus, and Chinese Holstein), and association analysis were carried out to evaluate the effects of genotypes of candidate genes on growth traits of three Chinese cattle. The objects were to discovery the hereditary characteristics and to explore molecular markers with significant effects on economic important traits for efficient selection and improvement of Chinese cattle, and to provide genetic information for foundation of molecular marker database, protection and usage of breed resource of Chinese cattle. The results were as follows:1. Relationship between genetic variation of exon2 and exon4 in NUCB1 gene and growth traits in Nanyang and Qinchuan cattleIn this study, polymorphism in the exon 1,2,3,4,5,6,7,8,9,10 11and 12 of bovine NUCB1 gene was detected by PCR-SSCP and DNA sequencing methods in 1181 individuals from six Chinese cattle breeds. The varations of four loci in NUCB1 gene were studied. Four SNPs (4191 G>C,6677 G>A,13404 A>C and 13421 C>U, ref. NC₀07316) were detected in 12 exones for the first time. Two haplotypes (A and B) and three observed genotypes (AA, AB, and BB). Those nucleotide sequences showed one mutations (G4191C) by comparisons with NC₀07316 (bovine NUCB1 gene DNA sequence):the NC₀07316:g.4191G>C mutations at the exon2; the NC₀07316:g.4191T>C mutation identified a missense mutation SNP (p.R67T), namely, Ile (AGG)> Ser (ACG) at position 67. But polymorphism of the NUCB1 gene was shown to not be associated with growth traits in the Nanyang, Jiaxian red and Qinchuan breed(P>0.05).Two haplotypes (A and B) and three observed genotypes (AA, AB, and BB). Those nucleotide sequences showed one mutations (G6677A) by comparisons with NC₀07316 (bovine NUCB1 gene DNA sequence):the NC₀07316:g.6677G>A mutations at the exon4; the NC₀07316:g.6677 G>A mutation identified a missense mutation SNP (p.F67T), namely, Phle (GCA)> Ser (ACA) at position 401. But polymorphism of the NUCB1 gene was shown to not be associated with growth traits in the Nanyang, Jiaxian red and Qinchuan breed(P>0.05). 2. Relationship between genetic variation of NUC2 gene and growth traits in three Chinese cattleIn this study, polymorphism in the exon 1,2,3,4,5,6,7,8,9,10 and 11 of bovine NUCB2 gene was detected by PCR-SSCP and DNA sequencing methods in 1811 individuals from six Chinese cattle breeds. The varations of eight loci in NUCB2 gene were studied. Eight SNPs (13530 A>C,1432 G>C,18025 T>C,23539 A>C,25439 A>T,26108 T>A,27451 G>A and 27472 T>C, ref. NC₀07313) were detected in 11 exones for the first time. Two haplotypes (A and B), three observed genotypes (AA, AB, and BB) and two SNPs (NC₀07313:g.27451G>A, NC₀07313:g.27472T>C) were detected. The frequencies of haplotypes A and B in inland Chinese three breeds were 0.414～0.494 and 0.506～0.586 respectively. The studied Nanyang, Jiaxian red and Qinchuan cattle populations were in Hardy-Weinberg equilibrium at SNPs locus of NUCB2 gene (P>0.05). Polymorphism of the NUCB2 gene was shown to be associated with growth traits in the three breed. The linkage of two mutant site in the bovine NUCB2 gene had significant effects on body length, body weight, heart girth, and average daily gain at 24 months old (P<0.05). Results of this study suggest that the NUCB2-gene-specific SNP may be a useful marker for growth traits in future marker-assisted selection programmes in inland Chinese cattle.Two haplotypes (A and B) and three observed genotypes (AA, AB, and BB). Those nucleotide sequences showed one mutations (G18025C) by comparisons with NC₀07313 (bovine NUCB2 gene DNA sequence):the NC₀07313:g.18025T>C mutations at the exon 3; the NC₀07313: g.18025T>C mutation identified a missense mutation SNP (p.I34S), namely, Ile (AUU)> Ser (AGU) at position 34. But polymorphism of the NUCB2 gene was shown to not be associated with growth traits in the Nanyang, Jiaxian red and Qinchuan breed(P<0.05).3. Relationship between genetic variation of exon3 in GAD1 gene and growth traits in three Chinese cattleIn this study, polymorphism in the exon 1,2,3,4 and 5 of bovine GAD1 gene was detected by PCR-SSCP and DNA sequencing methods in 1811 individuals from six Chinese cattle breeds. The varations of three loci in GAD1 gene were studied. Three SNPs (5056 C>T,11345 T>C, 1802 T>C, ref. NC₀07300) were detected in 5 exones for the first time. Two haplotypes (A and B) and three observed genotypes (AA, AB, and BB). Those nucleotide sequences showed one mutations (T12345C) by comparisons with NC₀07300 (bovine GADl gene DNA sequence):the NC₀07300:g.12345T>C mutations at the exon 3; the NC₀07300:g.12345T>C mutation identified a missense mutation SNP (p.F51L), namely, Phe (TTT)> Leu (CTT) at position 51. Polymorphism of the GAD1 gene was shown to be associated with growth traits in the Nanyang breed. The SNP in the bovine GADl gene had significant effects on body length, body weight, heart girth, and average daily gain at 24 months old (P<0.05).4. Relationship between genetic variation of exon10 in GAD2 gene and growth traits in Nanyang and Qinchuan cattleIn this study, polymorphism in the exon 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 and 16 and 5 of bovine GAD2 gene was detected by PCR-SSCP and DNA sequencing methods in 1181 individuals from six Chinese cattle breeds. Four SNPs (1238 G>A,1238 G>A,26357 G>T,37887 T>A ref. NC₀07311) were detected in 16 exones for the first time.Two haplotypes (A and B) and three observed genotypes (AA, AB, and BB). Those nucleotide sequences showed one mutations (T37887A) by comparisons with NC₀07311 (bovine GAD2 gene DNA sequence):the NC₀07311:g.37887T>A mutations at the exon 10; the NC₀07311:g.37887T>A mutation identified a missense mutation SNP (p.L1019Q), namely, Leu (CTG)> Gln (CAG) at position 1019. Polymorphism of the GAD2 gene was shown to only be associated with growth traits in the Nanyang breed. The SNP in the bovine GAD2 gene had significant effects on body weight, and heart girth at 24 months old (P<0.05).Two haplotypes (A and B) and three observed genotypes (AA, AB, and BB). Those nucleotide sequences showed one mutations (G1238A) by comparisons with NC 007311 (bovine GAD2 gene DNA sequence):the NC₀07311:g.12387G>A mutations at the exon 6; the NC 007311:g.1238T>A mutation identified a homonymy mutation SNP (p.K221K), namely, Lys (CCC)> Lys (CCA) at position 221. Polymorphism of the GAD2 gene was shown to be not associated with growth traits in the Nanyang Jiaxian red and Qinchuan breeds(P>0.05).