Ultra Large Gene Families: A Matter of Adaptation or Genomic Parasites?

Life

Thomas Wiehe¹  Philipp H. Schiffer¹  Martina Rauscher¹  Jan Gravemeyer¹ 

[1] Institute for Genetics, University of Cologne, Köln 50674, Germany;

关键词: gene family;    genome evolution;    adaptation;    neutral evolution;    selection;    NLR-genes;    run-away-evolution;    gene clusters;   

DOI  :  10.3390/life6030032

来源: DOAJ

【 摘 要 】

Gene duplication is an important mechanism of molecular evolution. It offers a fast track to modification, diversification, redundancy or rescue of gene function. However, duplication may also be neutral or (slightly) deleterious, and often ends in pseudo-geneisation. Here, we investigate the phylogenetic distribution of ultra large gene families on long and short evolutionary time scales. In particular, we focus on a family of NACHT-domain and leucine-rich-repeat-containing (NLR)-genes, which we previously found in large numbers to occupy one chromosome arm of the zebrafish genome. We were interested to see whether such a tight clustering is characteristic for ultra large gene families. Our data reconfirm that most gene family inflations are lineage-specific, but we can only identify very few gene clusters. Based on our observations we hypothesise that, beyond a certain size threshold, ultra large gene families continue to proliferate in a mechanism we term “run-away evolution”. This process might ultimately lead to the failure of genomic integrity and drive species to extinction.

【 授权许可】

Unknown