A widely employed germ cell marker is an ancient disordered protein with reproductive functions in diverse eukaryotes

• DOI: 10.7554/elife.19993
• Publication Date: 2016-10-08T12:00:33Z
• Authors: Michelle A Carmell; Gregoriy A Dokshin; Helen Skaletsky; Yueh-Chiang Hu; Josien C van Wolf...; Kyomi J Igarashi; Daniel W Bellott; Michael Nefedov; Peter W Reddien; George C Enders; Vladimir N Uversky; Craig C Mello; David C Page
• Keywords: Multicellular organism; Sexual reproduction

The advent of sexual reproduction and the evolution a dedicated germline in multicellular organisms are critical landmarks eukaryotic evolution. We report an ancient family GCNA (germ cell nuclear antigen) proteins that arose earliest eukaryotes, feature rapidly evolving intrinsically disordered region (IDR). Phylogenetic analysis reveals emerged before major lineages diverged; predates origin by billion years. Gcna gene expression is enriched reproductive cells across eukarya – either just prior to or during meiosis single-celled stem germ diverse animals. Studies Gcna-mutant C. elegans mice indicate has functioned for at least 600 million Homology IDR-containing implicated DNA damage repair suggests may protect genomic integrity carrying heritable genome.