title: Molecular characterization of two kazal-type serine proteinase inhibitor genes in the surf clam Mesodesma donacium exposed to Vibrio anguillarum.
abstract: This study reports two kazal-type serine protease inhibitors (KPI) identified in a cDNA library from the surf clam Mesodesma donacium, and characterized through Rapid Amplification of cDNA Ends (RACE). The KPIs, denoted as MdSPI-1 and MdSPI-2, presented full sequences of 1139 bp and 781 bp respectively. MdSPI-1 had a 5'untranslated region (UTR) of 175 bp, a 3'UTR of 283 bp and an open reading frame (ORF) of 681 pb that encodes for 227 amino acids. MdSPI-2 showed a 5'UTR of 70 bp, a 3'UTR of 279 bp and an ORF of 432 bp that encodes for 144 amino acids. Both sequences presented two kazal-type tandem domains. Phylogenetic analysis of MdSPI-1 and MdSPI-2 shows a main clade composed by other bivalve species and closely related crustaceans. Real time PCR analysis showed that MdSPI-1 is mainly up-regulated in mantle, foot, gills and muscle tissues, while MdSPI-2 is expressed principally in foot tissue. Moreover, to evaluate the immune response of MdSPI-1 and MdSPI-2, infections with Vibrio anguillarum were performed. Herein, MdSPI-1 and MdSPI-2 transcription expression were significantly up-regulated at 2 and 8 h post-challenge. Our results suggest that MdSPI-1 and MdSPI-2 are important humoral factors of innate immunity in M. donacium.
authors.affiliation: Laboratory of Biotechnology and Aquatic Genomics, Interdisciplinary Center for Sustainable Aquaculture Research (INCAR), University of Concepción, Concepción, Chile.
authors.forename: Waleska
authors.initials: W
authors.lastname: Maldonado-Aguayo
authors.forename: Gustavo
authors.initials: G
authors.lastname: Núñez-Acuña
authors.forename: Valentina
authors.initials: V
authors.lastname: Valenzuela-Muñoz
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Chávez-Mardones
authors.forename: Cristian
authors.initials: C
authors.lastname: Gallardo-Escárate
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D049872:Bivalvia / Q000235:genetics* / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology; D002677:Chile; D003001:Cloning, Molecular; D005786:Gene Expression Regulation; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010802:Phylogeny; D060888:Real-Time Polymerase Chain Reaction; D016415:Sequence Alignment; D015842:Serine Proteinase Inhibitors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014733:Vibrio / Q000502:physiology
chemical_list: D015842:Serine Proteinase Inhibitors