Zona pellucida protein ZP2 is expressed in the oocyte of Japanese quail (Coturnix japonica).
The avian perivitelline layer (PL), a vestment homologous to the zona pellucida (ZP) of mammalian oocytes, is composed of at least three glycoproteins. Our previous studies have demonstrated that the matrix's components, ZP3 and ZPD, are synthesized in ovarian granulosa cells. Another component, ZP1, is synthesized in the liver and is transported to the ovary by blood circulation. In this study, we report the isolation of cDNA encoding quail ZP2 and its expression in the female bird. By RNase protection assay and in situ hybridization, we demonstrate that ZP2 transcripts are restricted to the oocytes of small white follicles (SWF). The expression level of ZP2 decreased dramatically during follicular development, and the highest expression was observed in the SWF. Western blot and immunohistochemical analyses using the specific antibody against ZP2 indicate that the 80 kDa protein is the authentic ZP2, and the immunoreactive ZP2 protein is also present in the oocytes. Moreover, ultrastructural analysis demonstrated that the immunoreactive ZP2 localizes to the zona radiata, the perivitelline space, and the oocyte cytoplasm in the SWF. By means of western blot analysis and immunofluorescence microscopy, we detected a possible interaction of the recombinant ZP2 with ZP3 and that this interaction might lead to the formation of amorphous structure on the cell surface. These results demonstrate for the first time that the avian ZP gene is expressed in the oocyte, and that the ZP2 protein in the oocyte might play a role for the PL formation in the immature follicles of the ovary.
Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, 836 Ohya, Shizuoka 422-8529, Japan.
Mihoko
M
Kinoshita
Daniela
D
Rodler
Kenichi
K
Sugiura
Kayoko
K
Matsushima
Norio
N
Kansaku
Kenichi
K
Tahara
Akira
A
Tsukada
Hiroko
H
Ono
Takashi
T
Yoshimura
Norio
N
Yoshizaki
Ryota
R
Tanaka
Tetsuya
T
Kohsaka
Tomohiro
T
Sasanami
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D016466:CHO Cells; D003001:Cloning, Molecular; D003370:Coturnix / Q000235:genetics / Q000378:metabolism*; D006224:Cricetinae; D003412:Cricetulus; D004527:Egg Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009865:Oocytes / Q000378:metabolism* / Q000648:ultrastructure; D012333:RNA, Messenger / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D014162:Transfection; D000072216:Zona Pellucida Glycoproteins
D004527:Egg Proteins; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; D000072216:Zona Pellucida Glycoproteins