Ballester M, Revilla M, Puig-Oliveras A, Marchesi J A P, Castelló A, Corominas J, Fernández A I, Folch J M
Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Campus UAB, Bellaterra, 08193, Barcelona, Spain.
Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (Consorci CSIC-IRTA-UAB-UB), Edifici CRAG, Campus UAB, Bellaterra, 08193, Barcelona, Spain.
Anim Genet. 2016 Oct;47(5):552-9. doi: 10.1111/age.12462. Epub 2016 Jun 14.
APOA2 is a protein implicated in triglyceride, fatty acid and glucose metabolism. In pigs, the APOA2 gene is located on pig chromosome 4 (SSC4) in a QTL region affecting fatty acid composition, fatness and growth traits. In this study, we evaluated APOA2 as a candidate gene for meat quality traits in an Iberian × Landrace backcross population. The APOA2:c.131T>A polymorphism, located in exon 3 of APOA2 and determining a missense mutation, was associated with the percentage of hexadecenoic acid [C16:1(n-9)], linoleic acid [C18:2(n-6)], α-linolenic acid [C18:3(n-3)], dihomo-gamma-linolenic acid [C20:3(n-6)] and polyunsaturated fatty acids (PUFAs) in backfat. Furthermore, this SNP was associated with the global mRNA expression levels of APOA2 in liver and was used as a marker to determine allelic expression imbalance by pyrosequencing. We determined an overexpression of the T allele in heterozygous samples with a mean ratio of 2.8 (T/A), observing a high variability in the allelic expression among individuals. This result suggests that complex regulatory mechanisms, beyond a single polymorphism (e.g. epigenetic effects or multiple cis-acting polymorphisms), may be regulating APOA2 gene expression.
载脂蛋白A2是一种与甘油三酯、脂肪酸和葡萄糖代谢有关的蛋白质。在猪中，APOA2基因位于猪4号染色体（SSC4）上的一个数量性状基因座区域，该区域影响脂肪酸组成、脂肪含量和生长性状。在本研究中，我们在伊比利亚猪×长白猪回交群体中评估了APOA2作为肉质性状候选基因的可能性。位于APOA2第3外显子且导致错义突变的APOA2:c.131T>A多态性，与背膘中十六碳烯酸[C16:1(n-9)]、亚油酸[C18:2(n-6)]、α-亚麻酸[C18:3(n-3)]、二高-γ-亚麻酸[C20:3(n-6)]和多不饱和脂肪酸（PUFA）的百分比相关。此外，该单核苷酸多态性与肝脏中APOA2的整体mRNA表达水平相关，并被用作通过焦磷酸测序确定等位基因表达失衡的标记。我们在杂合样本中确定了T等位基因的过表达，平均比例为2.8（T/A），观察到个体间等位基因表达存在高度变异性。这一结果表明，除了单一多态性（如表观遗传效应或多个顺式作用多态性）之外，复杂的调控机制可能在调节APOA2基因的表达。
