Robertson H M
Department of Entomology, University of Illinois at Urbana-Champaign, 505 S. Goodwin, Urbana, IL 61801, USA.
Chem Senses. 2001 Feb;26(2):151-9. doi: 10.1093/chemse/26.2.151.
The seven transmembrane receptor (str) and srj (renamed from stl) families of chemoreceptors have been updated and the genes formally named following completion of the Caenorhabditis elegans genome sequencing project. Analysis of gene locations revealed that 84% of the 320 genes and pseudogenes in these two families reside on the large chromosome V. Movements to other chromosomes, especially chromosome IV, have nevertheless been relatively common, but only one has led to further gene family diversification. Comparisons with homologs in C. briggsae indicated that 22.5% of these genes have been newly formed by gene duplication since the species split, while also showing that four have been lost by large deletions. These patterns of gene evolution are similar to those revealed by analysis of the equally large srh family of chemoreceptors, and are likely to reflect general features of nematode genome dynamics. Thus large random deletions presumably balance the rapid proliferation of genes and their degeneration into pseudogenes, while gene movement within and between chromosomes keeps these nematode genomes in flux.
在秀丽隐杆线虫基因组测序项目完成后，对化学感受器的七个跨膜受体（str）家族和srj（由stl重命名）家族进行了更新，并正式命名了相关基因。基因定位分析表明，这两个家族中的320个基因和假基因中有84%位于大的第五条染色体上。不过，转移到其他染色体，尤其是第四条染色体上的情况相对常见，但只有一次导致了进一步的基因家族多样化。与briggsae线虫中的同源物比较表明，自这两个物种分化以来，这些基因中有22.5%是通过基因复制新形成的，同时也表明有四个基因因大片段缺失而丢失。这些基因进化模式与对等大小的化学感受器srh家族分析所揭示的模式相似，可能反映了线虫基因组动态的一般特征。因此，大量随机缺失大概平衡了基因的快速增殖及其退化为假基因的过程，而染色体内部和染色体之间的基因移动使这些线虫基因组处于动态变化之中。
