Research Unit Molecular Biology, Research Institute for the Biology of Farm Animals (FBN), 18196 Dummerstorf, Germany.
Mol Biol Rep. 2011 Jun;38(5):2975-86. doi: 10.1007/s11033-010-9962-z. Epub 2010 Feb 2.
Two bovine transcripts encoded by the interleukin-1 receptor-associated kinase 1 (IRAK1) gene and the locus LOC618944 predicted as similar to human chromosome 6 open reading frame 52 (C6orf52) gene had indicated divergent expression in bovine skeletal muscle containing different amount of intramuscular fat in a pilot screening experiment. However, for both loci any role in the regulation of energy or fat metabolism is not yet described. In this study, we validated and refined gene structure, screened for mRNA splice variants and analyzed the tissue-specific gene expression patterns of both loci as a prerequisite to elucidate their potential physiological function. Based on comparative sequence analysis, a new full-length gene model for the bovine IRAK1 gene was developed and confirmed experimentally. Expression of IRAK1 mRNA was found in a variety of tissues, and a splice variant was identified in skeletal muscle caused by an in-frame deleted segment of 210 bp affecting regions of intrinsic disorder in the respective protein. For the locus LOC618944, our data contributed to a revised gene model and its assignment to BTA23 (bovine chromosome 23) on the current bovine genome assembly supported by comparative similarity analysis between the bovine and human genomes and experimental data. Furthermore, we identified several splice variants in mammary gland, fat and skeletal muscle tissue and detected a highly similar processed pseudogene on BTA26. All transcript variants of LOC618944 detected in the analyzed tissues represent noncoding RNAs. For both loci, our results suggest yet undetected physiological functions in tissues relevant for fat or energy metabolism in cattle.
在一项初步筛选实验中，我们发现牛白细胞介素-1 受体相关激酶 1（IRAK1）基因和预测与人染色体 6 开放阅读框 52（C6orf52）基因相似的 LOC618944 基因的两个牛转录本在含有不同肌内脂肪量的牛骨骼肌中表现出不同的表达模式。然而，对于这两个基因座，它们在调节能量或脂肪代谢方面的作用尚未被描述。在本研究中，我们验证并细化了基因结构，筛选了 mRNA 剪接变体，并分析了这两个基因座的组织特异性基因表达模式，作为阐明其潜在生理功能的前提。基于比较序列分析，我们为牛 IRAK1 基因开发了一个新的全长基因模型，并通过实验证实。IRAK1 mRNA 的表达存在于多种组织中，在骨骼肌中发现了一个剪接变体，这是由 210 bp 的无义缺失片段引起的，该片段影响了相应蛋白质的固有无序区域。对于 LOC618944 基因座，我们的数据为其修订后的基因模型提供了贡献，并将其分配到 BTA23（牛染色体 23）上，这一结果得到了牛和人类基因组之间的比较相似性分析和实验数据的支持。此外，我们在乳腺、脂肪和骨骼肌组织中鉴定了几个剪接变体，并在 BTA26 上检测到了一个高度相似的加工假基因。在所分析的组织中检测到的 LOC618944 的所有转录变体均为非编码 RNA。对于这两个基因座，我们的结果表明，在与牛的脂肪或能量代谢相关的组织中存在尚未被发现的生理功能。
