title: Nlrp2, a maternal effect gene required for early embryonic development in the mouse.
abstract: Maternal effect genes encode proteins that are produced during oogenesis and play an essential role during early embryogenesis. Genetic ablation of such genes in oocytes can result in female subfertility or infertility. Here we report a newly identified maternal effect gene, Nlrp2, which plays a role in early embryogenesis in the mouse. Nlrp2 mRNAs and their proteins (∼118 KDa) are expressed in oocytes and granulosa cells during folliculogenesis. The transcripts show a striking decline in early preimplantation embryos before zygotic genome activation, but the proteins remain present through to the blastocyst stage. Immunogold electron microscopy revealed that the NLRP2 protein is located in the cytoplasm, nucleus and close to nuclear pores in the oocytes, as well as in the surrounding granulosa cells. Using RNA interference, we knocked down Nlrp2 transcription specifically in mouse germinal vesicle oocytes. The knockdown oocytes could progress through the metaphase of meiosis I and emit the first polar body. However, the development of parthenogenetic embryos derived from Nlrp2 knockdown oocytes mainly blocked at the 2-cell stage. The maternal depletion of Nlrp2 in zygotes led to early embryonic arrest. In addition, overexpression of Nlrp2 in zygotes appears to lead to normal development, but increases blastomere apoptosis in blastocysts. These results provide the first evidence that Nlrp2 is a member of the mammalian maternal effect genes and required for early embryonic development in the mouse.
authors.affiliation: Key Laboratory of Animal Reproductive Physiology and Embryo Technology, College of Veterinary Medicine, Northwest Agriculture and Forestry University, Yangling, Shanxi, People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Peng
authors.forename: Bohao
authors.initials: B
authors.lastname: Chang
authors.forename: Chenglong
authors.initials: C
authors.lastname: Lu
authors.forename: Jianmin
authors.initials: J
authors.lastname: Su
authors.forename: Yongyan
authors.initials: Y
authors.lastname: Wu
authors.forename: Pin
authors.initials: P
authors.lastname: Lv
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Wang
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.forename: Bowei
authors.initials: B
authors.lastname: Zhang
authors.forename: Fusheng
authors.initials: F
authors.lastname: Quan
authors.forename: Zekun
authors.initials: Z
authors.lastname: Guo
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins; D001755:Blastocyst / Q000166:cytology / Q000378:metabolism; D002460:Cell Line; D004622:Embryo, Mammalian / Q000196:embryology / Q000378:metabolism*; D047108:Embryonic Development / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D055785:Gene Knockdown Techniques; D042541:Intracellular Space / Q000378:metabolism; D008297:Male; D051379:Mice; D009865:Oocytes / Q000166:cytology / Q000378:metabolism; D010312:Parthenogenesis; D021381:Protein Transport; D011506:Proteins / Q000235:genetics* / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D015053:Zygote / Q000166:cytology / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; C572552:Nlrp2 protein, mouse; D011506:Proteins; D012333:RNA, Messenger