title: Characterization of a vasa-like gene from the pacific white shrimp Litopenaeus vannamei and its expression during oogenesis.
abstract: The vasa gene encodes an ATP-dependent RNA helicase belonging to the DEAD-box family that, in many organisms, is specifically expressed in germline cells throughout the life cycle. In this study we first cloned Pacific white shrimp (Litopenaeus vannamei) partial cDNAs of two members of the DEAD-box family, one belonging to the vasa subfamily (Lv-Vasa) and the other to the PL10 subfamily (Lv-PL10). Examination of their spatial expression pattern in adult tissues revealed that Lv-Vasa is restricted to the gonads, whereas Lv-PL10 is found in gonads as well as in somatic tissues. Next, we cloned the full-length shrimp vasa cDNA and found that Lv-Vasa encoded a protein with a DEAD-like helicase domain followed by a helicase superfamily C-terminal domain. In addition, Lv-Vasa encoded N-terminal three repeats of the C2HC-type zinc finger domain, a motif encoded by vasa genes of several crustaceans and several other invertebrate organisms. In situ hybridization of ovarian sections showed that the Lv-Vasa transcript is localized to the cytoplasm of the oocyte throughout oogenesis. The abundance of Lv-Vasa mRNA in mature oocytes suggests a maternal contribution for the developing embryo. It is demonstrated that the vasa homolog from L. vannamei is a gonad specific germline cell marker that could be exploited to enhance our understanding of developmental and reproductive processes in the germline of this economically important shrimp.
authors.affiliation: Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University, Beer-Sheva, Israel.
authors.forename: Eli D
authors.initials: ED
authors.lastname: Aflalo
authors.forename: Anna
authors.initials: A
authors.lastname: Bakhrat
authors.forename: Shaul
authors.initials: S
authors.lastname: Raviv
authors.forename: Daniel
authors.initials: D
authors.lastname: Harari
authors.forename: Amir
authors.initials: A
authors.lastname: Sagi
authors.forename: Uri
authors.initials: U
authors.lastname: Abdu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D053487:DEAD-box RNA Helicases / Q000235:genetics*; D017931:DNA Primers; D033364:Decapoda / Q000235:genetics / Q000502:physiology*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D009866:Oogenesis / Q000502:physiology*; D010053:Ovary / Q000166:cytology / Q000502:physiology; D010140:Pacific Ocean; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016335:Zinc Fingers / Q000235:genetics
chemical_list: D017931:DNA Primers; D012333:RNA, Messenger; D053487:DEAD-box RNA Helicases