In the present study, we investigated the major histocompatibility complex (MHC)-B haplotypes diversity of Sri Lankan indigenous chickens from three different geographical sites consisting of highly mixed populations using 90 SNPs in the MHC-B region. A total of 48 haplotypes were identified. Those included 37 novel haplotypes and 11 previously identified ‘standard’ haplotypes. The MHC-linked marker, LEI0258, had 23 alleles showing less diversity than defined by MHC-B SNP haplotypes. Among those identified haplotypes, five standard haplotypes—BSNP-O02, BSNP-M01, BSNP-A04, BSNP-K03, BSNP-T04—were most commonly observed, suggesting past introgression of imported breeds. Comparison of the MHC-B haplotypes of Sri Lankan and four other global populations with previously defined haplotypes indicated the sharing of 23 standard haplotypes with common origins. Novel haplotypes are population-specific and not shared among the geographical boundaries. Backyard indigenous chickens are unselected, highly crossbred, and generally thrive under dynamic environmental conditions. Hence free-range production systems may be responsible for maintaining high diversity in the MHC-B region with novel haplotypes.

中文翻译：

---

使用 MHC-B SNP 面板比较斯里兰卡本土鸡与五个全球鸡群的主要组织相容性复合体-B 变异性

在本研究中，我们使用 MHC- B区域的90 个 SNP 研究了来自三个不同地理地点的斯里兰卡本土鸡的主要组织相容性复合体 (MHC) -B单倍型多样性，这些地点由高度混合的种群组成。共鉴定出 48 个单倍型。其中包括 37 个新的单倍型和 11 个先前确定的“标准”单倍型。MHC 连锁标记 LEI0258 有 23 个等位基因，显示的多样性低于 MHC- B SNP 单倍型定义的多样性。在这些鉴定的单倍型中，最常观察到五种标准单倍型——BSNP-O02、BSNP-M01、BSNP-A04、BSNP-K03、BSNP-T04，这表明过去进口品种的基因渗入。MHC- B 的比较斯里兰卡和其他四个具有先前定义的单倍型的全球人群的单倍型表明共享 23 个具有共同起源的标准单倍型。新的单倍型是特定于人群的，在地理边界之间不共享。后院本土鸡未经选择，高度杂交，通常在动态环境条件下茁壮成长。因此，自由放养生产系统可能负责保持具有新单倍型的 MHC- B区域的高度多样性。