Exon-intron organization of TRGC genes in sheep
Exon-intron organization of TRGC genes in sheep
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DOI：
10.1007/s002510100340
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发表时间：
2001-07-01
期刊：
影响因子：
3.2
通讯作者：
Ciccarese, S
中科院分区：
文献类型：
--
作者：
Miccoli, MC;Lipsi, MR;Ciccarese, S
一系列来自绵羊文库的基因组克隆用于确定TRGC 2、TRGC 3和TRGC 4基因的种系构型和外显子-内含子组织。根据分子生物学分析的结果，我们将该基因组序列与已知的绵羊全cDNA序列进行了比较和比对，并推断了该反刍动物TRGC基因的外显子-内含子结构，EX 1对应于二硫键连接的恒定区，EX 3对应于跨膜区和胞质区，在所有基因中长度相似。相反，编码铰链的EX 2A、EX 2B和EX 2C外显子在基因之间的数量和长度不同，并且EX 2A包含TTKPP基序，无论其是以单个形式还是三重形式出现。分子数据还表明，至少有一个额外的基因存在于绵羊。系统发育分析将反刍动物TRGC基因分为两个簇，这两个簇可能来自两种祖先形式，这两种祖先形式经历了一系列复制，产生了新的序列，这些新序列被选择，然后固定在反刍动物谱系中。TRGC基因在系统发育树中的聚类分布与其在胎儿发育过程中的表达之间的相关性进行了讨论。
A series of genomic clones derived from a sheep library were used to determine the germline configuration and the exon-intron organization of TRGC2, TRGC3, and TRGC4 genes. Based on the outcomes of molecular analysis, we compared and aligned the genomic sequences with the known complete cDNA sequences of sheep and deduced the exon-intron organization of TRGC genes in this ruminant animal, EX1, corresponding to the disulfide-linked constant domain, and EX3, corresponding to the transmembrane and cytoplasmatic domains, are similar in length in all genes. Conversely, the hinge-encoding EX2A, EX2B, and EX2C exons differ in number and length between genes, and EX2A contains the TTKPP motif irrespective of whether it occurs in single or triplicate form. The molecular data also indicate that at least one additional gene is present in sheep. Phylogenetic analysis grouped the ruminant TRGC genes in two clusters that could have emerged from two ancestral forms that underwent a series of duplications giving rise to the new sequences that were selected and then fixed in the ruminant lineages. A correlation between the cluster distribution in the phylogenetic tree of TRGC genes and their expression during fetal development is discussed.