Boeddrich A, Burgtorf C, Roest Crollius H, Hennig S, Bernot A, Clark M, Reinhardt R, Lehrach H, Francis F
Max-Planck-Institut für Molekulare Genetik, Ihnestrasse 73, Berlin (Dahlem), D-14195, Germany.
Genomics. 1999 Apr 1;57(1):164-8. doi: 10.1006/geno.1998.5732.
A prerequisite to understanding the evolution of the human X chromosome is the analysis of synteny of X-linked genes in different species. We have focused on the spermine synthase gene in human Xp22. 1. We show that whereas the human gene spans a genomic region of 54 kb, the Fugu rubripes gene is encompassed in a 4.7-kb region. However, we could not find conserved synteny between this region of human Xp22 and the equivalent F. rubripes region. A cosmid clone containing the F. rubripes gene does not contain other X-linked genes. Instead we identified homologs of human genes that are autosomally localized: the ryanodine receptor type I (RYRI), which is implicated in malignant hyperthermia and central core disease, and the HE6 gene. Comparison of the F. rubripes, Tetraodon fluviatilis, mouse, human, and Danio rerio 5'UTRs of spermine synthase highlights conserved sequences potentially involved in regulation. Interestingly, pseudogenes of this gene that are present in the human and mouse genomes seem to be absent in the compact F. rubripes genome. Analysis of a D. rerio PAC clone containing spermine synthase shows an intermediate genomic size in this fish. Sequence analysis of this PAC clone did not reveal other known genes: neither the RYRI gene, nor the HE6 gene, nor other human Xp22 genes were identified.
理解人类X染色体进化的一个先决条件是分析不同物种中X连锁基因的同线性。我们聚焦于人类Xp22.1区域的精胺合成酶基因。我们发现，人类基因跨越54 kb的基因组区域，而红鳍东方鲀的基因包含在一个4.7 kb的区域内。然而，我们在人类Xp22的这个区域与红鳍东方鲀的等效区域之间未发现保守的同线性。一个包含红鳍东方鲀基因的黏粒克隆不包含其他X连锁基因。相反，我们鉴定出了人类那些定位于常染色体上的基因的同源物：与恶性高热和中央轴空病相关的I型兰尼碱受体（RYRI）以及HE6基因。对红鳍东方鲀、青鳉、小鼠、人类和斑马鱼精胺合成酶5'非翻译区的比较突出了可能参与调控的保守序列。有趣的是，在紧凑的红鳍东方鲀基因组中似乎不存在人类和小鼠基因组中存在的该基因的假基因。对一个包含精胺合成酶的斑马鱼PAC克隆的分析表明该鱼类的基因组大小处于中间水平。对这个PAC克隆的序列分析未揭示其他已知基因：既未鉴定出RYRI基因，也未鉴定出HE6基因，也未鉴定出其他人类Xp22基因。
