Molecular characterization and association of lactoferrin gene to subclinical mastitis in goats (Capra hircus)

ABSTRACT. The study characterized the lactoferrin (Lf) mRNA gene in different goat breeds in the Philippines and determined its association with subclinical mastitis (SCM). The study involved collection of milk at second week of lactation (n=75) and blood samples (n=5) to obtain extracted RNA and using cDNA to amplify Lf gene through polymerase chain reaction. The nucleotide and amino acid sequences were determined and used as reference in the evaluation of phylogenetic relationship. Amplified products were utilized for RFLP analysis before determining the association of the gene with SCM. Results of the study demonstrated that Lf gene in goats registered a molecular weight of 2135. Nucleotide and amino acid sequence of Lf gene revealed high similarity (99%) in Saanen, Anglo-Nubian and Philippine native goats with that of Capra hircus (U53857) Lf gene submitted to GenBank. Phylogenetic studies showed that Lf gene of Anglo-Nubian, Saanen and Native goats clade together with Lf gene of C. hircus (U53857). Three genotypes in goats were documented using the restriction enzymes AluI and HaeIII. Based on the Statistical analysis, association (comp 5.65, p = 0.0308) has been established between the Lf genes of goats with genotype BB to SCM using HaeIII restriction enzyme.

摘要：本研究对菲律宾不同山羊品种的乳铁蛋白（lactoferrin, Lf）mRNA基因进行了表征，并明确了其与亚临床乳腺炎（subclinical mastitis, SCM）的关联。本研究于泌乳第二周采集奶样（n=75）与血样（n=5）以提取RNA，利用cDNA通过聚合酶链式反应（polymerase chain reaction）扩增Lf基因。测定核苷酸与氨基酸序列，并以此为参照评估其系统发育关系。扩增产物用于限制性片段长度多态性（restriction fragment length polymorphism, RFLP）分析，随后明确该基因与SCM的关联。研究结果显示，山羊Lf基因的分子量为2135。萨能山羊、英格鲁-努比亚山羊与菲律宾本地山羊的Lf基因核苷酸及氨基酸序列与提交至GenBank的家山羊（Capra hircus，U53857）Lf基因具有99%的高相似性。系统发育研究显示，英格鲁-努比亚山羊、萨能山羊与本地山羊的Lf基因与家山羊（C. hircus，U53857）的Lf基因聚为一支。利用限制性内切酶AluI与HaeIII，在山羊中鉴定出3种基因型。基于统计分析，采用HaeIII限制性内切酶时，基因型为BB的山羊Lf基因与SCM之间已确立关联（comp 5.65，p = 0.0308）。