Evolutionary history of the vertebrate Piwi gene family

PeerJ

article

Javier Gutierrez¹  Roy Platt²  Juan C. Opazo³  David A. Ray⁶  Federico Hoffmann⁷  Michael Vandewege¹ 

[1] Department of Biology, Eastern New Mexico University;Host Pathogen Interaction Program, Texas Biomedical Research Institute;Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile;Millennium Nucleus of Ion Channel-Associated Diseases;Integrative Biology Group, Universidad Austral de Chile;Department of Biological Sciences, Texas Tech University;Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University;Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University

关键词: RNAi;    Gene duplication;    Argonaute gene family;    Selection;    Transcriptomics;    Phylogenetics;    Synteny;   

DOI  :  10.7717/peerj.12451

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

PIWIs are regulatory proteins that belong to the Argonaute family. Piwis are primarily expressed in gonads and protect the germline against the mobilization and propagation of transposable elements (TEs) through transcriptional gene silencing. Vertebrate genomes encode up to four Piwi genes: Piwil1, Piwil2, Piwil3 and Piwil4, but their duplication history is unresolved. We leveraged phylogenetics, synteny and expression analyses to address this void. Our phylogenetic analysis suggests Piwil1 and Piwil2 were retained in all vertebrate members. Piwil4 was the result of Piwil1 duplication in the ancestor of gnathostomes, but was independently lost in ray-finned fishes and birds. Further, Piwil3 was derived from a tandem Piwil1 duplication in the common ancestor of marsupial and placental mammals, but was secondarily lost in Atlantogenata (Xenarthra and Afrotheria) and some rodents. The evolutionary rate of Piwil3 is considerably faster than any Piwi among all lineages, but an explanation is lacking. Our expression analyses suggest Piwi expression has mostly been constrained to gonads throughout vertebrate evolution. Vertebrate evolution is marked by two early rounds of whole genome duplication and many multigene families are linked to these events. However, our analyses suggest Piwi expansion was independent of whole genome duplications.

【 授权许可】

CC BY