A total of 184 Djallonké (West African Dwarf) sheep of Burkina Faso were analysed for Copy Number Variations (CNV) using Ovine 50 K SNP BeadChip genotyping data and two different CNV calling platforms: PennCNV and QuantiSNP. Analyses allowed to identify a total of 63 candidate Copy Number Variations Regions (CNVR) on 11 different ovine chromosomes covering about 82.5 Mb of the sheep genome. Gene-annotation enrichment analysis allowed to identify a total of 751 potential candidate ovine genes located in the candidate CNVR bounds. Functional annotation allowed to identify five statistically significant Functional Clusters (FC; enrichment factor > 1.3) involving 61 candidate genes. All genes forming significantly enriched FC were located on ovine chromosome (OAR) 21. FC1 (22 genes including PAG4 and PAG6) and FC5 (three genes: CTSC, CTSW and CTSF), coding proteases (peptidases and cathepsins, respectively), were involved in reproductive performance and modulation of gestation. Both FC3 and FC4 were involved in inflammatory and immunologic response through coding serum amyloid A and B-box-type zinc finger proteins, respectively. Finally, FC2 consisted of 27 genes (including OR10G6 and OR8B8) involved in olfactory receptor activity, key for animals adapting to new food resources. CNVR identified on at least 15% of individuals were considered CNVR hotspots and further overlapped with previously reported quantitative trait loci (QTL). CNVR hotspots spanning genes putatively involved with lipid metabolism (SKP1, TCF7, JADE2, UBE2B and SAR1B) and differential expression in mammary gland (SEC24A and CDKN2AIPNL) on OAR5 and dairy traits (CCDC198 and SLC35F4) on OAR7 overlapped with QTL associated with lipid metabolism, milk protein yield and milk fat percentage. Information obtained from local sheep populations naturally adapted to harsh environments contributes to increase our understanding of the genomic importance of CNV.

中文翻译：

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Djallonké绵羊拷贝数变异区域的功能表征

使用 Ovine 50 K SNP BeadChip 基因分型数据和两个不同的 CNV 调用平台：PennCNV 和 QuantiSNP，分析了布基纳法索总共 184 只 Djallonké（西非矮人）绵羊的拷贝数变异 (CNV)。分析允许在覆盖约 82.5 Mb 绵羊基因组的 11 条不同绵羊染色体上识别总共 63 个候选拷贝数变异区域 (CNVR)。基因注释富集分析允许识别位于候选 CNVR 范围内的总共 751 个潜在候选绵羊基因。功能注释允许识别涉及 61 个候选基因的五个具有统计意义的功能簇（FC；富集因子 > 1.3）。所有形成显着富集 FC 的基因都位于绵羊染色体 (OAR) 21. FC1 (22 个基因，包括PAG4和PAG6 ) 和 FC5（三个基因：CTSC、CTSW和CTSF），编码蛋白酶（分别为肽酶和组织蛋白酶）参与繁殖性能和妊娠调节。FC3 和 FC4 分别通过编码血清淀粉样蛋白 A 和 B 盒型锌指蛋白参与炎症和免疫反应。最后，FC2 由 27 个基因（包括OR10G6和OR8B8) 参与嗅觉受体活动，是动物适应新食物资源的关键。在至少 15% 的个体上鉴定出的 CNVR 被认为是 CNVR 热点，并与之前报道的数量性状基因座 (QTL) 进一步重叠。CNVR 热点跨越假定与脂质代谢有关的基因（SKP1、TCF7、JADE2、UBE2B和SAR1B）和乳腺中OAR5 和乳制品性状（CCDC198和SLC35F4）的差异表达（SEC24A和CDKN2AIPNL）) 在 OAR7 上与与脂质代谢、乳蛋白产量和乳脂百分比相关的 QTL 重叠。从自然适应恶劣环境的当地绵羊种群中获得的信息有助于增加我们对 CNV 基因组重要性的理解。