Cloning, developmental expression, and immunohistochemistry of cyclooxygenase 2 in the endometrium during embryo implantation and gestation in the mink (Mustela vison).
Cyclooxygenase (COX) is the first rate-limiting enzyme in the biosynthesis of PGs. There are two isoforms, COX-1, a constitutive enzyme and COX-2, the induced form, products of two different genes. In this study, we report COX-2 complementary DNA cloning, uterine expression, and immunohistochemical localization in the mink uterus during postimplantation gestation. The open reading frame of mink COX-2 contains 1812 nucleotides encoding 604 amino acids. The homologies are 86%, 83%, 83%, 83%, 85%, and 84% in nucleotides and 86%, 87%, 87%, 85%, 86%, and 88% in amino acids with human, mouse, rat, guinea pig, sheep, and rabbit, respectively. All domains associated with biological activity are conserved in the mink. Northern analysis revealed a transcript of 4.2 kb for COX-2 in mink uterus and adrenal. Semiquantitative RT-PCR showed that COX-2 messenger RNA is not present during diapause. The abundance of COX-2 messenger RNA reached its maxima (P < 0.05) on days 3-5 of postimplantation, gradually decreased through day 9, and was not present thereafter. By immunohistochemistry, COX-2 was present in uterine epithelium, stroma, and necks of endometrial glands at sites of implantation. COX-2 expression appears to be induced in the endometrium by the embryo and may play a role in implantation and placentation in the mink.
Song
J H
JH
Centre de Recherche en Reproduction Animale, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, Québec, Canada.
Sirois
J
J
Houde
A
A
Murphy
B D
BD
D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D003001:Cloning, Molecular; D051546:Cyclooxygenase 2; D010064:Embryo Implantation; D004717:Endometrium / Q000201:enzymology*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis / Q000737:chemistry / Q000235:genetics*; D008565:Membrane Proteins; D008907:Mink; D011247:Pregnancy; D011451:Prostaglandin-Endoperoxide Synthases / Q000032:analysis / Q000737:chemistry / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D017385:Sequence Homology; D014018:Tissue Distribution; D014599:Uterus / Q000737:chemistry
D007527:Isoenzymes; D008565:Membrane Proteins; D012333:RNA, Messenger; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases