College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, Henan, China.
Henan Innovative Engineering Research Center of Poultry Germplasm Resource, Zhengzhou.
J Anim Sci. 2020 May 1;98(5). doi: 10.1093/jas/skaa122.
An increasing number of studies have shown that quantitative trait loci (QTLs) at the end of chromosome 1 identified in different chicken breeds and populations exert significant effects on growth traits in chickens. Nevertheless, the causal genes underlying the QTL effect remain poorly understood. Using an updated gene database, a novel lncRNA (named LncFAM) was found at the end of chromosome 1 and located in a growth and digestion QTL. This study showed that the expression level of LncFAM in pancreas tissues with a high weight was significantly higher than that in pancreas tissues with a low weight, which indicates that the expression level of LncFAM was positively correlated with various growth phenotype indexes, such as growth speed and body weight. A polymorphism screening identified four polymorphisms with strong linkage disequilibrium in LncFAM: a 5-bp indel in the second exon, an A/G base mutation, and 7-bp and 97-bp indels in the second intron. A study of a 97-bp insertion in the second intron using an F2 chicken resource population produced by Anka and Gushi chickens showed that the mutant individuals with genotype II had the highest values for body weight (BW) at 0 days and 2, 4, 6, 8, 10 and 12 weeks, shank girth (SG) at 4, 8 and 12 weeks, chest width (CW) at 4, 8 and 12 weeks, body slant length (BSL) at 8 and 12 weeks, and pelvic width (PW) at 4, 8 and 12 weeks, followed by ID and DD genotypes. The amplification and typing of 2,716 chickens from ten different breeds, namely, the F2 chicken resource population, dual-type chickens, including Xichuan black-bone chickens, Lushi green-shell layers, Dongxiang green-shell layers, Changshun green-shell layers, and Gushi chickens, and commercial broilers, including Ross 308, AA, Cobb and Hubbard broilers, revealed that II was the dominant genotype. Interestingly, only genotype II existed among the tested populations of commercial broilers. Moreover, the expression level in the pancreas tissue of Ross 308 chickens was significantly higher than that in the pancreas tissue of Gushi chickens (P < 0.001), which might be related to the conversion rates among different chickens. The prediction and verification of the target gene of LncFAM showed that LncFAM might regulate the expression of its target gene FAM48A through cis-expression. Our results provide useful information on the mutation of LncFAM, which can be used as a potential molecular breeding marker.
越来越多的研究表明，不同鸡种和群体中位于染色体 1 末端的数量性状基因座（QTL）对鸡的生长性状有显著影响。然而，QTL 效应背后的因果基因仍知之甚少。利用最新的基因数据库，在染色体 1 末端发现了一个新的长非编码 RNA（命名为 LncFAM），并位于生长和消化 QTL 中。本研究表明，在体重较高的胰腺组织中，LncFAM 的表达水平明显高于体重较低的胰腺组织，这表明 LncFAM 的表达水平与生长速度和体重等各种生长表型指标呈正相关。多态性筛选在 LncFAM 中鉴定出四个强连锁不平衡的多态性：第二外显子中的 5-bp 缺失、A/G 碱基突变，以及第二内含子中的 7-bp 和 97-bp 缺失。使用安卡和固始鸡杂交产生的 F2 鸡资源群体对第二内含子中的 97-bp 插入进行研究表明，基因型 II 的突变个体在 0 天和 2、4、6、8、10 和 12 周时体重（BW）最高，4、8 和 12 周时胫围（SG）最高，4、8 和 12 周时胸宽（CW）最高，8 和 12 周时体斜长（BSL）最高，4、8 和 12 周时骨盆宽（PW）最高，其次是 ID 和 DD 基因型。对来自十个不同品种的 2716 只鸡进行扩增和分型，包括 F2 鸡资源群体、双型鸡，包括淅川黑骨鸡、卢氏绿壳蛋鸡、东乡绿壳蛋鸡、长顺绿壳蛋鸡和固始鸡，以及商业肉鸡，包括罗斯 308、AA、科布和哈伯德肉鸡，结果表明 II 是优势基因型。有趣的是，商业肉鸡的测试群体中仅存在基因型 II。此外，罗斯 308 鸡胰腺组织中的表达水平明显高于固始鸡（P<0.001），这可能与不同鸡种之间的转化率有关。LncFAM 靶基因的预测和验证表明，LncFAM 可能通过顺式表达调控其靶基因 FAM48A 的表达。我们的研究结果为 LncFAM 的突变提供了有用的信息，可以作为潜在的分子育种标记。
