Amarger V, Erlandsson R, Pielberg G, Jeon J-T, Andersson L
Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Cytogenet Genome Res. 2003;102(1-4):163-72. doi: 10.1159/000075743.
The PRKAG3 gene encodes the gamma3 chain of AMP-activated protein kinase (AMPK). A non-conservative missense mutation in the PRKAG3 gene causes a dominant phenotype involving abnormally high glycogen content in pig skeletal muscle. We have determined >126 kb (in 13 contigs) of porcine genomic sequence surrounding the PRKAG3 gene and the corresponding mouse region covering the gene. A comparison of these PRKAG3 sequences and the human sequence was conducted and used to predict evolutionarily conserved regions, including regulatory regions. A comparison of the human genomic sequence and a porcine BAC sequence containing the PRKAG3 gene, revealed a conserved organization and the presence of three additional genes, CYP27A1 (cytochrome P450, family 27, subfamily A, polypeptide 1), STK36 (Serine Threonine Kinase 36), and the homolog of the unidentified human mRNA KIAA0173. Interspersed repetitive elements constituted 51.4 and 38.6% of this genomic region in human and pig, respectively. We were able to reliably align 12.6 kb of orthologous repeats shared between pig and human and these showed an average sequence identity of 72.4%. Our analysis revealed that the human KIAA0173 gene harbors alternative 5' untranslated exons originating from repetitive elements. This provides an obvious example how transposable elements may affect gene evolution.
PRKAG3基因编码AMP激活蛋白激酶（AMPK）的γ3链。PRKAG3基因中的一个非保守错义突变导致一种显性表型，表现为猪骨骼肌中糖原含量异常高。我们已经确定了围绕PRKAG3基因的超过126 kb（分布在13个重叠群中）的猪基因组序列以及覆盖该基因的相应小鼠区域。对这些PRKAG3序列和人类序列进行了比较，并用于预测进化上保守的区域，包括调控区域。对人类基因组序列和包含PRKAG3基因的猪BAC序列进行比较，揭示了一个保守的组织架构以及另外三个基因的存在，即CYP27A1（细胞色素P450，家族27，亚家族A，多肽1）、STK36（丝氨酸苏氨酸激酶36）以及未鉴定的人类mRNA KIAA0173的同源物。散布的重复元件分别占人类和猪该基因组区域的51.4%和38.6%。我们能够可靠地比对猪和人类之间共有的12.6 kb直系同源重复序列，这些序列的平均序列同一性为72.4%。我们的分析表明，人类KIAA0173基因含有源自重复元件的可变5'非翻译外显子。这提供了一个明显的例子，说明转座元件可能如何影响基因进化。
