title: Structural analysis of the three vitellogenin genes in Drosophila melanogaster.
abstract: Genomic fragments coding for sequences expressed as abundant mRNA in female Drosophila melanogaster were isolated from a lambda library. Hybridization of these clones to polytene chromosomes. in situ, identified four which mapped to X chromosomal region 9A to 9B, the locus for yolk proteins 1 and 2 (Ypl,2) and two which mapped to 12A6-7 to 12D3, the locus for Yp3. These clones were mapped with restriction enzymes, and the coding regions and regions of homology determined by Southern blots probed with cDNA, 5'-end-labelled RNA and nick-translated DNA. Heteroduplex and R-loop mapping confirmed that three of the clones carried two genes separated by about 1.4 kb and oriented in opposite directions. Southern blots probed with cDNA made from alkali-hydrolyzed RNA showed that these genes had their 5' ends next to each other. All 3 genes show homology to each other and have a main coding region of about 1.3 kb, the approximate size for the mRNAs.
mesh_terms: D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004262:DNA Restriction Enzymes; D004274:DNA, Recombinant / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics*; D005796:Genes; D008074:Lipoproteins / Q000235:genetics*; D008970:Molecular Weight; D009693:Nucleic Acid Hybridization; D014176:Protein Biosynthesis; D014819:Vitellogenins / Q000235:genetics*
chemical_list: D004274:DNA, Recombinant; D008074:Lipoproteins; D014819:Vitellogenins; D004262:DNA Restriction Enzymes