title: Complete sequence of Litopenaeus vannamei (Crustacea: Decapoda) vitellogenin cDNA and its expression in endocrinologically induced sub-adult females.
abstract: The gene that encodes vitellogenin (Vg), the precursor of the major yolk protein, vitellin, is expressed during vitellogenesis in decapod crustaceans. In this study, we sequenced the full-length cDNA from the Pacific white shrimp Litopenaeus vannamei Vg gene (LvVg). This is the first open thelycum penaeid shrimp Vg cDNA to be sequenced. The transcript encodes a 2587 amino acid polypeptide with up to 85% identity to Vg of different penaeid species. Peptide mass fingerprints (PMFs) of the vitelline polypeptides suggest that the predicted endoprotease cleavage site at amino acids 725-728 does indeed undergo cleavage. Five prominent high-density lipoprotein polypeptides of masses 179, 113, 78, 61, and 42kDa were isolated from vitellogenic ovary, and their PMFs were determined by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) spectrometry. It is likely that these polypeptides are all products of the LvVg gene. Removal of the X-organ sinus gland complex (XO-SG), which secretes the neurohormones that control the endocrine system regulating molt and reproduction, can induce both these processes. During the course of a number of molt cycles in induced sub-adult females, periodic ovarian growth and resorption were observed. Ovary growth correlated with LvVg expression in both the hepatopancreas and the ovary. Expression in ovaries of induced intermolt-early premolt females was significantly higher compared to all other sub-groups. Expression in ovaries of induced females was significantly higher compared to hepatopancreas at all molt cycle stages. Periodicity of molt and vitellogenesis in endocrinologically induced sub-adult shrimps may serve as a model to study alternate regulation of gene expression during these two processes.
authors.affiliation: Department of Life Sciences, National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva 84105, Israel.
authors.forename: Shaul
authors.initials: S
authors.lastname: Raviv
authors.forename: Shmuel
authors.initials: S
authors.lastname: Parnes
authors.forename: Carmen
authors.initials: C
authors.lastname: Segall
authors.forename: Claytus
authors.initials: C
authors.lastname: Davis
authors.forename: Amir
authors.initials: A
authors.lastname: Sagi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary / Q000737:chemistry*; D033364:Decapoda / Q000235:genetics* / Q000502:physiology; D005260:Female; D015870:Gene Expression; D043143:Hepatopancreas / Q000737:chemistry; D008075:Lipoproteins, HDL / Q000737:chemistry / Q000302:isolation & purification; D008969:Molecular Sequence Data; D018978:Molting; D012252:Natural Family Planning Methods; D016366:Open Reading Frames; D010053:Ovary / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism; D010449:Peptide Mapping; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis; D017422:Sequence Analysis, DNA; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014818:Vitellogenesis; D014819:Vitellogenins / Q000737:chemistry / Q000235:genetics*
chemical_list: D018076:DNA, Complementary; D008075:Lipoproteins, HDL; D012333:RNA, Messenger; D014819:Vitellogenins