Minet A D, Chiquet-Ehrismann R
Friedrich Miescher-Institute, PO Box 2543, CH-4002, Basel, Switzerland.
Gene. 2000 Oct 17;257(1):87-97. doi: 10.1016/s0378-1119(00)00388-7.
Teneurins are a novel family of transmembrane proteins conserved between invertebrates and vertebrates. There are two members in Drosophila, one in C. elegans and four members in mouse. Here, we describe the analysis of the genomic structure of the human teneurin-1 gene. The entire human teneurin-1 (TEN1) gene is contained in eight PAC clones representing part of the chromosomal locus Xq25. Interestingly, many X-linked mental retardation syndromes (XLMR) and non-specific mental retardation (MRX) are mapped to this region. The location of the human TEN1 together with the neuronal expression makes TEN1 a candidate gene for XLMR and MRX. We also identified large parts of the human teneurin-2 sequence on chromosome 5 and sections of human teneurin-4 at chromosomal position 11q14. Database searches resulted in the identification of ESTs encoding parts of all four human members of the teneurin family. Analysis of the genomic organization of the Drosophila ten-a gene revealed the presence of exons encoding a long form of ten-a, which can be aligned with all other teneurins known. Sequence comparison and phylogenetic trees of teneurins show that insects and vertebrates diverged before the teneurin ancestor was duplicated independently in the two phyla. This is supported by the presence of conserved intron positions between teneurin genes of man, Drosophila and C. elegans. It is therefore not possible to class any of the vertebrate teneurins with either Drosophila Ten-a or Ten-m. The C-terminal part of all teneurins harbours 26 repetitive sequence motifs termed YD-repeats. YD-repeats are most similar to the repeats encoded by the core of the rearrangement hot spot (rhs) elements of Escherichia coli. This makes the teneurin ancestor a candidate gene for the source of the rhs core acquired by horizontal gene transfer.
Ten eurins是一类在无脊椎动物和脊椎动物之间保守的新型跨膜蛋白家族。果蝇中有两个成员，秀丽隐杆线虫中有一个成员，小鼠中有四个成员。在此，我们描述了对人类ten eur in - 1基因的基因组结构的分析。整个人类ten eur in - 1（TEN1）基因包含在代表染色体位点Xq25一部分的八个PAC克隆中。有趣的是，许多X连锁智力迟钝综合征（XLMR）和非特异性智力迟钝（MRX）都定位于该区域。人类TEN1的位置以及其在神经元中的表达使TEN1成为XLMR和MRX的候选基因。我们还在5号染色体上鉴定出了人类ten eur in - 2序列的大部分以及在染色体位置11q14处的人类ten eur in - 4的片段。数据库搜索导致鉴定出编码ten eur in家族所有四个人类成员部分的EST。对果蝇ten - a基因的基因组组织分析揭示了存在编码ten - a长形式的外显子，其可与所有其他已知的ten eur ins进行比对。ten eur ins的序列比较和系统发育树表明，在ten eur in祖先在两个门中独立复制之前，昆虫和脊椎动物就已经分化。人类、果蝇和秀丽隐杆线虫的ten eur in基因之间保守内含子位置的存在支持了这一点。因此，不可能将任何脊椎动物的ten eur ins与果蝇的Ten - a或Ten - m归为一类。所有ten eur ins的C末端部分含有26个称为YD重复的重复序列基序。YD重复与大肠杆菌重排热点（rhs）元件核心编码的重复最为相似。这使得ten eur in祖先成为通过水平基因转移获得的rhs核心来源的候选基因。
