Dynamic regulation of expression of colony-stimulating factor 1 in the reproductive tract of cattle during the estrous cycle and in pregnancy.
Colony-stimulating factor 1 (CSF-1) is a hematopoetic cytokine that also plays an important role in placental physiology. We report here the molecular cloning of two alternative splice variants of the bovine gene coding for a putative secreted and a membrane-bound form of the cytokine and the dynamic regulation of expression in the reproductive tract of cattle during the estrous cycle and pregnancy. Bovine CSF-1 was expressed mainly as the 3- and 4-kilobase (kb) transcripts, but 1.4- and 0.8-kb mRNAs were also detected in Day 50-70 pregnant uterine tissue. During the estrous cycle, both the 4- and 3-kb mRNAs were present, but the 3-kb putative membrane-bound form was more abundant than the 4-kb secreted form during diestrus. This pattern of expression was reversed in pregnancy, so that the exponential increase in CSF-1 expression seen during pregnancy was due predominantly to increased abundance of the 4-kb transcript. The change in the 4-kb:3-kb ratio was detected between Day 14 and Day 17, approximately the time of maternal recognition of pregnancy. Thus, CSF-1 was identified as one gene whose expression in the uterus might be altered early in response to the presence of the conceptus. CSF-1 was also expressed in the extraembryonic membranes of the conceptus and in the trophoblastic cells of the fetal cotyledons after the formation of the placentomes. The high level of CSF-1 expression during bovine pregnancy in uteroplacental tissues is consistent with its proposed role in placental physiology.
Lee
Rita S F
RS
Reproductive Technologies Group, AgResearch, Ruakura Research Centre, Hamilton 2001, New Zealand. rita.lee@agresearch.co.nz
Li
Ning
N
Ledgard
Anita M
AM
Pollard
Jeffrey W
JW
D020413:3' Untranslated Regions / Q000235:genetics; D017398:Alternative Splicing / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D002417:Cattle; D003001:Cloning, Molecular; D030762:Estrous Cycle / Q000235:genetics* / Q000502:physiology*; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000235:genetics* / Q000502:physiology*; D005836:Genitalia, Female / Q000378:metabolism*; D017403:In Situ Hybridization; D016173:Macrophage Colony-Stimulating Factor / Q000096:biosynthesis* / Q000235:genetics*; D008969:Molecular Sequence Data; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000235:genetics* / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction
D020413:3' Untranslated Regions; D012333:RNA, Messenger; D016173:Macrophage Colony-Stimulating Factor