Vitellogenin gene of the silkworm, Bombyx mori: Structure and sex‐dependent expression

Abstract

Ah&actVitellogenin of Bomhyx mori is a precursor of major yolk protein synthesized in the female fat body at larval-pupal ecdysis. The gene for B. mori vitellogenin is composed of seven exons interspersed by six introns. Developmental profile of the primary transcript of the gene indicated that the biosynthesis of B. mori vitellogenin is regulated transcriptionally in a sex-and stage-dependent manner in the fat body. The Arg-X-Arg-Arg sequence, which conforms to the recognition site of mammalian furin, occurs in a region just upstream of the putative proteolytic cleavage site of B. mori previtellogenin.

Isolation and sequence of a partial vitellogenin cDNA from the cockroach,Blattella germanica (L.) (Dictyoptera, Blattellidae), and characterization of the vitellogenin gene expression

“…4. Alignments of the subdomain IV (Chen et al, 1997) of the vitellogenin sequences of 7 species of insects: boll weevil, Anthonomus grandis (Trewitt et al, 1992;M72980); yellow fever mosquito, Aedes aegypti (Chen et al, 1994;U02548); silkworm moth, Bombyx mori (Yano et al, 1994a;D13160); gypsy moth, Lymantria dispar (Hiremath and Lehtoma, 1997a;V60186); turnip sawfly, Athalia rosae (Nose et al, 1997;AB007850), the parasitoid wasp Pimpla nipponica (Nose et al, 1997; AF026789); German cockroach, Blattella germanica (present study; AJ005115); and the nematode Caenorhabditis elegans (vit-5: Spieth et al, 1985;X03044). The PILEUP program from the GCG package was used, and results were displayed by BOX, from the same package.…”

Egg extract promotes cell migration and growth in primary culture of early embryos in the silkworm, Bombyx mori (Lepidoptera: Bombycidae)

“…Aliquots (10 pl) of the egg extracts were loaded onto a 12.5% acrylamide gel with a size marker and subjected to electrophoresis (EzRun C ϩ ; ATTO, Tokyo, Japan). The anti-vitellin heavy chain protein of B. mori antibody used in the present study was supplied by Dr Izumi (Yano et al, 1994). This anti-serum was from rabbits immunized by vitellin heavy chain.…”

Subunit cleavage of mosquito pro-vitellogenin by a subtilisin-like convertase.

“…In most insects, Vg precursors are cleaved into two subunits (apoproteins) which, after posttranslational modifications, recombine to comprise a mature oligomeric Vg molecule (7,10). The cloning and characterization of Vg cDNAs from several insects have revealed a striking conservation of the pro-Vg cleavage site containing the paired basic consensus sequence for convertases (11)(12)(13). Furthermore, the adjacent j3-turns that are required for the recognition of the paired basic motif by convertases (14,15) have been identified at the cleavage sites of insect Vgs (J.-S.C. and A.S.R., unpublished).…”