ABSTRACT Lipocalin-2 (LCN2) is a secreted protein, produced e.g. by neutrophils – the main group of cells involved in inflammatory conditions caused by pathogenic bacteria. So far, no studies have been carried out on the genetic variability of the LCN2 gene in cattle in terms of immunity/susceptibility to mastitis in cows. This study concerns the analysis of polymorphisms within the LCN2 gene in cattle and their impact on the production traits and the incidence of mastitis in Polish Holstein-Friesian cows. Using the PCR-RFLP method, two polymorphisms – g.98784892C > T and g.98784893T > G – were identified in intron 5 of the LCN2 gene, which represent two haplotypes (CT and TG, respectively). The CT haplotype was shown to have a significant impact on the average somatic cell score of milk, however, the CT and TG haplotypes were found to have no impact on the milk yield, protein, fat and lactose levels, or the incidence of mastitis in cows. An analysis of polymorphisms in the bovine LCN2 gene could be employed in future to support selection in dairy cattle breeding programmes focused towards the somatic cell count in milk, and the LCN2 gene itself could become a molecular marker of cows’ immunity to mastitis.

中文翻译：

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牛 lipocalin-2 单倍型对波兰荷斯坦-弗里斯兰牛乳成分、体细胞评分和乳腺炎发病率的影响

摘要 Lipocalin-2 (LCN2) 是一种分泌蛋白，例如由嗜中性粒细胞产生 - 中性粒细胞是致病细菌引起的炎症状态的主要细胞群。到目前为止，尚未对牛 LCN2 基因在奶牛对乳腺炎的免疫力/易感性方面的遗传变异性进行研究。本研究涉及牛 LCN2 基因内多态性的分析及其对波兰荷斯坦-弗里斯奶牛生产性状和乳腺炎发病率的影响。使用 PCR-RFLP 方法，在 LCN2 基因的内含子 5 中鉴定了两种多态性——g.98784892C > T 和 g.98784893T > G，它们分别代表两种单倍型（CT 和 TG）。CT 单倍型被证明对牛奶的平均体细胞评分有显着影响，然而，发现 CT 和 TG 单倍型对奶牛的产奶量、蛋白质、脂肪和乳糖水平或乳腺炎的发生率没有影响。对牛 LCN2 基因多态性的分析可用于支持奶牛育种计划的选择，该计划侧重于牛奶中的体细胞计数，并且 LCN2 基因本身可以成为奶牛对乳腺炎免疫的分子标记。