RESUMO
The ATP-binding cassette transporter ABCG2 (also known as breast cancer resistance protein, BCRP) belongs to the ATP-binding cassette (ABC) family of transmembrane drug transporters, playing a crucial role in the protection of various cells and tissues against xenotoxins and/or endotoxins. Recently, several studies have proposed it as the potential gene underlying the QTL on bovine chromosome 6. Hence, in this study, the PCR-SSCP method was applied to detect two polymorphisms (A â C and A â G) in the target sequence coding nucleotide-binding domain (NBD) region of ABCG2 and evaluate its associations with milk production traits and mastitis-related traits among Chinese Holsteins. In the analyzed population, the allelic frequencies for the A and B alleles were 0.5990 and 0.4010, respectively and the genotypic frequencies were in Hardy-Weinberg disequilibrium (P < 0.01). Moreover, significant statistical relationships between the polymorphisms of ABCG2 gene and following traits, including milk yields, milk protein percentage and somatic cell scores (SCS), were found (P < 0.05). When compared with AA genotype, BB genotype was associated with higher milk yields during 1st and 2nd lactations, as well as lower milk protein percentage and SCS. Thus, BB genotype is suggested to be a molecular marker for superior milk performance.
Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Leite/química , Polimorfismo de Nucleotídeo Único , Alelos , Animais , Sequência de Bases , Bovinos , China , Laticínios , Feminino , Genótipo , Humanos , Proteínas do Leite/análise , Proteínas do Leite/genética , Polimorfismo Conformacional de Fita Simples , Isoformas de Proteínas/genética , Análise de Sequência de DNARESUMO
There is evidence that stearoyl-CoA desaturase (SCD) is a key enzyme for lipid metabolism. Changes in enzyme activity that depends on SCD gene polymorphism and regulation could cause variations of fatty acid composition of meat and milk. We investigated genetic variability in caprine SCD, analyzing 335 animals belonging to three goat breeds by single-strand conformation polymorphism and DNA sequencing. Six single nucleotide polymorphism were identified, in intron 3 (585T-->A and 601A-->G; Ref. AF422168), intron 4 (719T-->A; AF422169), and exon 6 (690 A-->G, 718 C-->G, and 802 A-->C; AF422171). The less polymorphic SNP 601A-->G displayed variability only in Xuhuai and Boer breeds. Across breeds, the average frequency for the least frequent alleles ranged from 0.1158 to 0.2532. The three SNPs in exon 6 resulted in variations of amino acids 313 tyr --> cys, 322 phe --> leu, and 350 arg --> ser. The allelic distribution in exon 6 of Xuhuai was significantly different from Boer and Haimen.
Assuntos
Cabras/genética , Polimorfismo de Nucleotídeo Único , Estearoil-CoA Dessaturase/genética , Animais , Ácidos Graxos/metabolismo , Frequência do Gene , Marcadores Genéticos/genética , Cabras/anatomia & histologia , Cabras/metabolismo , Carne , Polimorfismo Conformacional de Fita SimplesRESUMO
Single nucleotide polymorphisms (SNPs) of hircine myf-5, myf-6 genes and 5'flanking region of the myoD gene (myoD 5') were analyzed by PCR-SSCP in Boer goat and Xuhuai white goat. Three genotypes were found at the myf-5 locus of Xuhuai white goat, denoted AA, AB and BB, while all of Boer goats were of AA genotype. Only AA and AB genotypes were found at myf-6 and myoD 5' loci. The effects of genotypes of myf-5, myf-6 and myoD 5'flanking region loci on body measurement traits were estimated. The results showed that genotypes at the myf-5 locus were significantly associated with hucklebone width and hucklebone width index in Xuhuai white goat (P<0.05). Genotypes at the myf-6 locus were significantly associated with withers heights and hucklebone width index in Boer goat (P<0.05), but no significant associations were found for any traits in Xuhuai white goat. The myoD 5' locus was not significantly associated with any traits in both types of goat.
