Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell'Università 16, 35020 Legnaro, Italy.
Department of Biology, University of Padova, Via Ugo Bassi 58/B, 35121 Padova, Italy.
Sci Rep. 2016 Dec 8;6:38673. doi: 10.1038/srep38673.
Skeletal anomalies in farmed fish are a relevant issue affecting animal welfare and health and causing significant economic losses. Here, a high-density genetic map of European seabass for QTL mapping of jaw deformity was constructed and a genome-wide association study (GWAS) was carried out on a total of 298 juveniles, 148 of which belonged to four full-sib families. Out of 298 fish, 107 were affected by mandibular prognathism (MP). Three significant QTLs and two candidate SNPs associated with MP were identified. The two GWAS candidate markers were located on ChrX and Chr17, both in close proximity with the peaks of the two most significant QTLs. Notably, the SNP marker on Chr17 was positioned within the Sobp gene coding region, which plays a pivotal role in craniofacial development. The analysis of differentially expressed genes in jaw-deformed animals highlighted the "nervous system development" as a crucial pathway in MP. In particular, Zic2, a key gene for craniofacial morphogenesis in model species, was significantly down-regulated in MP-affected animals. Gene expression data revealed also a significant down-regulation of Sobp in deformed larvae. Our analyses, integrating transcriptomic and GWA methods, provide evidence for putative mechanisms underlying seabass jaw deformity.
养殖鱼类的骨骼异常是一个影响动物福利和健康并导致重大经济损失的相关问题。在这里，我们构建了欧洲鲈鱼用于下颌骨畸形 QTL 作图的高密度遗传图谱，并对总共 298 尾幼鱼进行了全基因组关联研究（GWAS），其中 148 尾属于四个全同胞家系。在 298 条鱼中，有 107 条受到下颌前突（MP）的影响。鉴定出与 MP 相关的三个显著 QTL 和两个候选 SNP。两个 GWAS 候选标记位于 ChrX 和 Chr17 上，都与两个最显著 QTL 的峰值非常接近。值得注意的是，Chr17 上的 SNP 标记位于 Sobp 基因编码区域内，该基因在颅面发育中起着关键作用。对下颌骨畸形动物中差异表达基因的分析强调了“神经系统发育”在 MP 中的关键途径。特别是，在模式物种中对颅面形态发生至关重要的基因 Zic2 在 MP 受影响的动物中显著下调。基因表达数据还显示 Sobp 在畸形幼虫中显著下调。我们的分析，整合了转录组学和 GWA 方法，为鲈鱼下颌骨畸形的潜在机制提供了证据。
