Oocyte-specific H2A variant H2af1o is required for cell synchrony before midblastula transition in early zebrafish embryos.
Oocyte-specific histone variants have been expected to play significant roles in early embryonic development, but the exact evidence and the biological function have remained unclear. Here, we present evidence that H2af1o, an oocyte-specific H2A variant, is required for cell synchrony before midblastula transition in early zebrafish embryos. The H2A variant is oocyte specific, peaks in mature eggs, and is supplied to early embryos. We constructed a series of deletion plasmids of the zebrafish h2af1o tagged with EGFP and determined the main key function regions including nuclear localization signal of N-terminal 25 amino acids and nucleosome binding region of 110-122 amino acid sequence in the C-terminus by microinjecting them into one-cell-stage zebrafish embryos. In comparison with ubiquitous H2A.X, the H2af1o was revealed to confer a more open structure than canonical H2A in the nucleosomes. Furthermore, we conducted the h2af1o-specific morpholino knockdown analysis in early embryos of zebrafish and revealed its biological function for maintaining cell synchrony division because the H2af1o deficiency disturbed cell synchrony in early cleavages before midblastula transition. Therefore, our current findings provided the first case to understand the biological function of maternal oocyte-specific histone variants in vertebrates.
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Graduate University of the Chinese Academy of Sciences, Wuhan, China.
Hua-Mei
HM
Yue
Zhi
Z
Li
Nan
N
Wu
Zhen
Z
Liu
Yang
Y
Wang
Jian-Fang
JF
Gui
D000818:Animals; D036703:Blastula / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects; D005260:Female; D054262:Gastrulation / Q000187:drug effects; D055785:Gene Knockdown Techniques; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006657:Histones / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D060172:Morpholinos / Q000494:pharmacology; D019913:Nuclear Localization Signals / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009707:Nucleosomes / Q000187:drug effects / Q000378:metabolism; D009865:Oocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009866:Oogenesis / Q000187:drug effects; D009928:Organ Specificity; D010446:Peptide Fragments / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D054730:Protein Interaction Domains and Motifs; D020033:Protein Isoforms / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D015027:Zebrafish / Q000196:embryology / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D006657:Histones; D060172:Morpholinos; D019913:Nuclear Localization Signals; D009707:Nucleosomes; D010446:Peptide Fragments; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins; D029961:Zebrafish Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins
cell synchrony; early cleavage; histone variant; midblastula transition; oocyte-specific histone