RESUMO
Fiber diameter is a useful indicator of wool traits and it is the main determinant of wool quality and value. A comparative study was conducted to analyze the abundance and expression of 13 candidate genes using expression profile microarray analysis and to identify novel molecular markers associated with wool traits to provide a molecular basis for improving wool quality in sheep. Genes associated with fineness of skin tissue were identified using a real-time reverse transcriptase-polymerase chain reaction method with 18SrRNA, ß-Actin, and GAPDH used for multi-reference normalization. The results indicated that the expression levels of TXNIP, TFDP1, and FAIM genes in super-fine type wool sheep were higher than those in fine-type wool sheep; the corresponding expression ratios of super-fine to fine wool sheep were 1.45, 1.57, and 2.55, respectively. The expression levels of PIK3CA, ADAM9, and FZD3 genes were lower in super-fine wool sheep compared with fine-type wool sheep; the corresponding expression ratios were 0.61, 0.65, and 0.52, respectively. The other genes tested (RPS6KA, ABCG2, GSTA1, PTPN13, GJB3, PPARD, and LAMB1) were similarly expressed in both types of wool sheep. These results infer that lower expression of PIK3CA, ADAM9, and FZD3 genes was associated with lower fiber diameter, whereas lower expression of TXNIP, TFDP1, and FAIM genes was associated with higher fiber diameter.
Assuntos
Perfilação da Expressão Gênica/métodos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Locos de Características Quantitativas , Ovinos/genética , Animais , Perfilação da Expressão Gênica/veterinária , Regulação da Expressão Gênica , Marcadores Genéticos , Análise de Sequência com Séries de Oligonucleotídeos/veterinária , Fenótipo , LãRESUMO
Cluster of differentiation 4 gene (CD4) is well known for its role in immunity, but its effects on production traits remain to be elucidated. The present study was designed to explore single nucleotide polymorphisms (SNPs) in the exons, flanking introns, and promoter of CD4, as well as to analyze their effects on milk production traits (percentage of protein, fat, and lactose; mastitis indicator traits somatic cell count; and somatic cell score). A total of 10 SNPs, including eight in the exon and two in the intron regions, were identified using pooled DNA sequencing. These SNPs were screened in a population of 258 Chinese Holstein using the SNaPshot technique. We analyzed the effects of SNPs, parity, herd, year, and season of calving on the production and mastitis indicator traits. Our analysis revealed two haplotypes and strong linkage disequilibrium (D' > 0.97) among all SNPs. All 10 SNPs were significantly associated with fat percentage (P < 0.01). Cows homozygous for the wild-type genotypes had higher fat percentages than those with the other genotypes. The dominant and additive effects were also significant for fat percentage (P < 0.05). These results suggest that CD4 plays a role in production traits as well as in immune function. The identified SNPs could be used as genetic markers for selection of dairy cows with improved fat percentage. We propose further studies of these SNPs in a larger population as well as further investigations of the function of this gene.
Assuntos
Antígenos CD4/genética , Marcadores Genéticos , Mastite Bovina/genética , Animais , Antígenos CD4/imunologia , Bovinos , Feminino , Genótipo , Haplótipos , Desequilíbrio de Ligação/genética , Mastite Bovina/patologia , Leite/metabolismo , Fenótipo , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNARESUMO
Isolation of sufficient quantities of high quality DNA is a prerequisite for molecular studies. Milk somatic cells can be used; however, inhibitors such as fats and proteins make milk a difficult medium for extracting large amounts of quality DNA. We optimized, evaluated and compared three methods, Modified Nucleospin Blood Kit method, Modified TianGen Kit method and Phenol-Chloroform method for genomic DNA extraction from bovine milk. Individual cows' milk and bulk milk samples were collected from a China agricultural university dairy farm. Genomic DNA extracted from each milk sample by the three methods was evaluated for quantity and purity by spectrophotometry and gel electrophoresis, as well as PCR and sequencing. All the three methods were found suitable for genomic DNA isolation from bovine milk, PCR applications, and sequencing. Comparing the three methods, we found that the Modified Nucleospin Blood Kit method was significantly better than the Phenol-Chloroform method in terms of quantity as well as quality (amount, concentration, 260/280 nm and 260/230 nm absorbance ratio), whereas, the Modified TianGen Kit method was more efficient than the Phenol-Chloroform method and cheaper than the Modified Nucleospine Blood Kit method; it yielded reasonably good quantities of good quality DNA and would be suitable for large-scale genotyping of lactating cows.