title: Schistosoma mansoni p48 eggshell protein gene: characterization, developmentally regulated expression and comparison to the p14 eggshell protein gene.
abstract: Egg production by worm pairs is a major cause of pathogenesis in schistosomiasis. To further the understanding of female reproductive development, we have isolated and characterized a complete copy of an eggshell protein precursor gene, p48. Sequence analysis reveals that the gene has 3 open reading frames and does not contain an intron. One of the open reading frames, ORF1, encodes a polypeptide of 50 kDa which shows strong homology to insect chorion proteins. Determination of the position of the mRNA cap-site facilitated identification of putative regulatory elements in the 5' upstream region of the gene. Some of these elements (e.g., TCACGT) have been shown to play a role in the regulation of chorion gene expression in insects. p48 mRNA is detectable only in mature female worms and the ability to detect the mRNA coincides temporally with worm pairing. Quantitative comparisons, during female reproductive development, of p48 transcripts to those from another eggshell protein precursor gene, p14, show that the p48 mRNA is significantly less abundant than p14 mRNA. In mature female worms, p48 mRNA can only be detected in vitelline cells. Antibodies made against the polypeptide sequence deduced from ORF1 of the p48 gene recognize a 50-kDa molecule in extracts from mature female worms, but not in extracts from immature females or males.
authors.affiliation: Department of Microbiology, School of Medicine and Biomedical Sciences, State University of New York, Buffalo 14214.
authors.forename: L L
authors.initials: LL
authors.lastname: Chen
authors.forename: D M
authors.initials: DM
authors.lastname: Rekosh
authors.forename: P T
authors.initials: PT
authors.lastname: LoVerde
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000947:Antigens, Helminth / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D015153:Blotting, Western; D002352:Carrier Proteins; D006224:Cricetinae; D004247:DNA; D004527:Egg Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D050612:Fatty Acid Transport Proteins; D005260:Female; D005786:Gene Expression Regulation; D015801:Helminth Proteins / Q000235:genetics*; D007106:Immune Sera; D008297:Male; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D012315:RNA Caps; D011817:Rabbits; D015183:Restriction Mapping; D012550:Schistosoma mansoni / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D013997:Time Factors
chemical_list: D000947:Antigens, Helminth; D002352:Carrier Proteins; D004527:Egg Proteins; D050612:Fatty Acid Transport Proteins; D015801:Helminth Proteins; D007106:Immune Sera; D026901:Membrane Transport Proteins; D012315:RNA Caps; C068709:SM14 protein, Schistosoma mansoni; C075553:p48 eggshell protein, Schistosoma mansoni; D004247:DNA