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  • 1
    Electronic Resource
    Electronic Resource
    Comparative Aspects of Conceptus Signals for Maternal Recognition of Pregnancy (1991)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 622 (1991), S. 0 
    Details
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-6632.1991.tb37863.x
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  • 2
    Electronic Resource
    Electronic Resource
    Transient expression of the cytochrome P450 aromatase gene in elongating porcine blastocysts is correlated with uterine insulin-like growth factor levels during peri-implantation development (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 37 (1994), S. 1-11 
    Details
    ISSN: 1040-452X
    Keywords: IGF-I ; IGF-II ; Uterus ; Embryo ; Estrogens ; Aromatase P450 ; Pregnancy ; RIA ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The insulin-like growth factors (IGFs-I and -II) are mediators of cellular growth and differentiation. The expression of these growth factor genes is temporally and hormonally regulated in the uterus during pregnancy, suggesting potentially important roles in embryonic development, implantation, and successful progression of pregnancy. A known regulator of uterine IGF-I secretion is estrogen, which is produced by pre-implantation mammalian embryos of several species and whose amounts may be influenced by growth factors via their effects on the transcriptional activities of steroidogenic enzyme genes. We have previously proposed that within the uterine microenvironment, a positive feedback loop may link uterine secretion of IGFs with embryonic production of estrogens to maintain and coordinate the timing of biological signals essential for embryo development. The present study examined the temporal relationships between the levels of conceptus cytochrome P450 aromatase mRNA and protein and concentrations of IGF-I and -II in uterine luminal fluids of pigs. A DNA fragment encoding a highly conserved region among mammalian aromatase P450 proteins was isolated by hybridization screening of a porcine genomic DNA library with a human aromatase P450 cDNA fragment as probe. A synthetic oligopeptide DDVIDGYPVKKGTNI within this highly conserved region was used to generate an antiserum in sheep that recognized a protein of Mr 49,000 in Western blot analysis of porcine ovarian, placental, endometrial, and conceptus extracts. A radioimmunoassay (RIA) for aromatase P450 was established and validated using this antiserum. RIA demonstrated highest levels of aromatase P450 protein in extracts of days 10, 11, and 12 porcine conceptuses with significantly diminished levels in elongated conceptuses at days 15 and 18. In the conceptus, aromatase P450 was localized to the inner cell layer (hypoblast) of the trophectoderm. A major mRNA transcript of aproximately 3 kb in length was demonstrated by Northern blot analysis of conceptus RNA with a porcine aromatase P450 antisense RNA probe. The relative levels of aromatase P450 mRNA were higher in conceptuses at day 12 than at days 15 and 18, in parallel with the levels of aromatase P450 protein. RIA of uterine luminal fluids demonstrated maximal concentrations of IGF-I at day 12, which were significantly decreased by day 15, and increased concentrations of IGF-II by day 12, which were maintained until day 18 of pregnancy. These results demonstrate that the transient expression of conceptus aromatase P450 mRNA and protein in elongating pig blastocysts is coincident with their capacity to secrete estrogens and with the rapidly changing concentrations of IGFs withing the uterine microenvironment. These results suggest that regulation of aromatase P450 gene expression by IGFs may represent one mechanism by which uterine factors modulate an embryonic function (e.g., estrogen production) that elicits coordinate changes in the endometrium in preparation for implantation. © 1994 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080370102
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  • 3
    Electronic Resource
    Electronic Resource
    Pregnancy-associated endometrial expression of antileukoproteinase gene is correlated with epitheliochorial placentation (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 38 (1994), S. 357-363 
    Details
    ISSN: 1040-452X
    Keywords: Placentation ; Cathepsin G ; Elastase ; Antileukoproteinase ; Uterus ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Uterine expression of the mRNA encoding antileukoproteinase (ALP) is highest in pig uterus during mid- to late pregnancy, suggesting a stage of pregnancy-dependent role for this elastase/cathepsin G protease inhibitor in feto-maternal interactions. To examine a potential relationship between uterine synthesis of ALP and the type of placentation in mammalian species, the expression of ALP mRNA and/or protein in pregnant mares, cows, rats, and mice was evaluated. Genomic DNA and mRNA hybridization analyses were performed using a porcine ALP cDNA as probe. The concentration of ALP protein in reproductive tissues was determined by RIA using a polyclonal antibody raised against a synthetic peoptide (ALP 16P) corresponding to amino acid residues 21-36 of the porcine ALP protein. A single ALP mRNA transcript of approximately 0.8 kb in length was detected in equine and bovine uterine tissues. The relative abundance of ALP mRNA in equine endometrium increased between days 125-170 (mid-pregnancy), and then decreased by day 215 of pregnancy. Similarly, the steady state levels of ALP mRNA in bovine endometrium and myometrium were higher during mid- to late than during early pregnancy. The levels of ALP mRNA in bovine fetal cotyledon were low and did not change significantly with stage of pregnancy. No hybridization was detected to pregnant rat endometrial tissues, although high stringency Southern blot analysis of porcine, bovine, and rat genomic DNAs using porcine ALP cDNA as probe predicted a high degree of nucleotide sequence homology in their respective ALP genes. In pregnant cows, concentrations of ALP protein were higher in maternal endometrium and myometrium than in fetal cotyledon. Tissue ALP content in bovine uterus increased between days 17-89, and then decreased by day 248 of pregnancy. In contrast, no ALP protein was detected in cytosolic extracts prepared from endometrium of pregnant rats and mice. THe demonstrated synthesis of ALP mRNA and/or protein in the endometrium of the mare and the cow similar to that of the pig, but not in the endometrium of the rat and mouse, during pregnancy indicates a potential correlation between endometrial ALP expression and epitheliochorial type of placentation in mammalian species. © 1994 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080380402
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  • 4
    Electronic Resource
    Electronic Resource
    Cloning and expression of a rat placental cDNA encoding a novel cathepsin L-related protein (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 40 (1995), S. 146-156 
    Details
    ISSN: 1040-452X
    Keywords: Cysteine protease ; Pregnancy ; Rodent ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Cathepsin L is a major lysosomal cysteine protease produced by mouse placenta and fibroblasts. This study characterizes a novel cathepsin L-related mRNA expressed in rat placenta. Immunological and nucleotide screening of a rat placental library identified six positive clones, the largest, pCLRP-9, being 924 base pairs in length. The combined sequences of all the clones contain an open reading frame of 711 nucleotides, a termination codon, a polyadenylation site, and 197 nucleotides of 3′ untranslated region, but lack the 5′ translation initiation codon. The pCLRP nucleotide sequence showed 60-64% identity to those of mouse, rat, and human cathepsin L. The deduced amino acid sequence of pCLRP codes for 237 amino acids, which align with the carboxy-terminal sequence of cathepsin L and has the active site residues characteristic of the cysteine protease family. Northern blot analysis showed hybridization of pCLRP with a major mRNA transcript of 1.3 kilobases expressed in placenta, but not kidney or liver. In contrast, a cDNA for mouse pro-cathepsin L hybridized with a transcript of 1.7 kilobases expressed in rat kidney, as well as placenta. During late gestation, steady-state levels of rat placental pCLRP mRNA were highest on day 18, whereas those of mouse procathepsin L were greatest on day 20 of gestation. Antiserum to mouse cathepsin L cross-reacted with four proteins of molecular weights 36,000 to 42,000 in rat placental culture medium, of which two were absent in the kidney. These data indicate that rat placenta expresses several species of cathepsin L-type proteins, which may be involved in placental function and nutrient supply. © 1995 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080400203
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  • 5
    Electronic Resource
    Electronic Resource
    Cloning of a novel rat placental prolactin-like protein C-related cDNAThe nucleotide sequence reported in this paper has been submitted to the GenBank/EMBL Data Bank, and may be located with the accession number U09099. (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 41 (1995), S. 167-176 
    Details
    ISSN: 1040-452X
    Keywords: Prolactin ; Placenta ; Pregnancy ; Rodent ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Prolactin-like protein C (PLP-C) is a major rat placental protein which is expressed during the second half of pregnancy and belongs to the growth hormone-prolactin family. Here we report on the isolation of overlapping rat placental cDNAs which specify a transcript of 915 base pairs and predict a 205-amino acid translated product. The full-length cDNA shares 93% homology with the nucleotide sequence reported for PLP-C, and the putative protein, which we designate PCRP (prolactin-like protein C-related protein), exhibits 88% homology with the PLP-C precursor protein. PCRP lacks the signal sequence and the first 2 N-terminal cysteine residues present in PLP-C. Northern blot analysis indicated the basal zone-specific expression of PCRP mRNA, with no detectable expression in decidua and labyrinth. Southern blot analysis of rat genomic DNA using PCRP cDNA as a probe demonstrated multiple hybridization bands, suggestive of a family of genes encoding prolactin-like proteins. Western immunoblot analysis of basal zone culture media using a PCRP antipeptide antiserum revealed at least 5 immunoreactive proteins. The existence of a PLP-C family of proteins in rat placenta after midpregnancy suggests their functional significance in the maintenance of pregnancy and fetal development. © 1995 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080410207
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