A widely employed germ cell marker is an ancient disordered protein with reproductive functions in diverse eukaryotes
Abstract
The advent of sexual reproduction and the evolution of a dedicated germline in multicellular organisms are critical landmarks in eukaryotic evolution. We report an ancient family of GCNA (germ cell nuclear antigen) proteins that arose in the earliest eukaryotes, and feature a rapidly evolving intrinsically disordered region (IDR). Phylogenetic analysis reveals that GCNA proteins emerged before the major eukaryotic lineages diverged; GCNA predates the origin of a dedicated germline by a billion years. Gcna gene expression is enriched in reproductive cells across eukarya - either just prior to or during meiosis in single-celled eukaryotes, and in stem cells and germ cells of diverse multicellular animals. Studies of Gcna-mutant C. elegans and mice indicate that GCNA has functioned in reproduction for at least 600 million years. Homology to IDR-containing proteins implicated in DNA damage repair suggests that GCNA proteins may protect the genomic integrity of cells carrying a heritable genome.
Article and author information
Author details
Funding
Howard Hughes Medical Institute
- Michelle A Carmell
- Gregoriy A Dokshin
- Helen Skaletsky
- Yueh-Chiang Hu
- Kyomi J Igarashi
- Daniel W Bellott
- Peter W Reddien
- Craig C Mello
Life Sciences Research Foundation
- Michelle A Carmell
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: All mouse studies were performed using a protocol approved by the Committee on Animal Care at the Massachusetts Institute of Technology (Protocol number: 0714-074-17).
Copyright
© 2016, Carmell et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 4,884
- views
-
- 1,082
- downloads
-
- 61
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Further reading
-
- Developmental Biology
During the first lineage segregation, mammalian embryos generate the inner cell mass (ICM) and trophectoderm (TE). ICM gives rise to the epiblast (EPI) that forms all cell types of the body, an ability referred to as pluripotency. The molecular mechanisms that induce pluripotency in embryos remain incompletely elucidated. Using knockout (KO) mouse models in conjunction with low-input ATAC-seq and RNA-seq, we found that Oct4 and Sox2 gradually come into play in the early ICM, coinciding with the initiation of Sox2 expression. Oct4 and Sox2 activate the pluripotency-related genes through the putative OCT-SOX enhancers in the early ICM. Furthermore, we observed a substantial reorganization of chromatin landscape and transcriptome from the morula to the early ICM stages, which was partially driven by Oct4 and Sox2, highlighting their pivotal role in promoting the developmental trajectory toward the ICM. Our study provides new insights into the establishment of the pluripotency network in mouse preimplantation embryos.
-
- Developmental Biology
- Neuroscience
The ligand Netrin mediates axon guidance through a combination of haptotaxis over short distances and chemotaxis over longer distances.