English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Background   Nucleoplasmin 2  ( npm2 ) is an essential maternal-effect gene that mediates early embryonic events through its function as a histone chaperone that remodels chromatin. Recently, two  npm2  ( npm2a  and  npm2b ) genes have been annotated in zebrafish. Thus, we examined the evolution of  npm2a  and  npm2b  in a variety of vertebrates, their potential phylogenetic relationships, and their biological functions using knockout models via the CRISPR/cas9 system.    Results  We demonstrated that the two  npm2  duplicates exist in a wide range of vertebrates, including sharks, ray-finned fish, amphibians, and sauropsids, while  npm2a  was lost in coelacanth and mammals, as well as some specific teleost lineages. Using phylogeny and synteny analyses, we traced their origins to the early stages of vertebrate evolution. Our findings suggested that  npm2a  and  npm2b  resulted from an ancient local gene duplication, and their functions diverged although key protein domains were conserved. We then investigated their functions by examining their tissue distribution in a wide variety of species and found that they shared ovarian-specific expression, a key feature of maternal-effect genes. We also demonstrated that both  npm2a  and  npm2b  are maternally-inherited transcripts in vertebrates, and that they play essential, but distinct, roles in early embryogenesis using zebrafish knockout models. Both  npm2a  and  npm2b  function early during oogenesis and may play a role in cortical granule function that impact egg activation and fertilization, while  npm2b  is also involved in early embryogenesis.    Conclusion  These novel findings will broaden our knowledge on the evolutionary history of maternal-effect genes and underlying mechanisms that contribute to vertebrate reproductive success. In addition, our results demonstrate the existence of a newly described maternal-effect gene,  npm2a , that contributes to egg competence, an area that still requires further comprehension.    Electronic supplementary material  The online version of this article (10.1186/s12862-018-1281-3) contains supplementary material, which is available to authorized users.

Double maternal-effect: duplicated nucleoplasmin 2 genes, npm2a and npm2b, with essential but distinct functions are shared by fish and tetrapods