title: Seasonal changes in gene expression and polymorphism of hsp70 in cultivated oysters (Crassostrea gigas) at extreme temperatures.
abstract: The HSP70 proteins are an important element of the response against thermal stress and infectious diseases, and they are highly conserved and ubiquitous. In some species, variations on the hsp70 encoding sequence resulted in intraspecific differential expression, which leads to variations on thermo-tolerance among individuals. This phenomenon has not been described in the Pacific oyster Crassostrea gigas, which is cultivated in Mexico under temperature conditions highly above the optimal for this species. The present study was aimed to identify associations between hsp70 genotypes and their expression levels in C. gigas. By analyzing a 603 bp fragment from the 3' end of the hsp70 gene, 21 different genotypes with 60 nucleotide polymorphic sites were detected, of which 34 sites were found in heterozygous condition. Although no correlation was found between genotype-expression-season, a minimum expression threshold that should be taken into account as an important feature for a future breeding program is proposed.
authors.affiliation: Universidad de Sonora, Departamento de Investigaciones Científicas y Tecnológicas, Hermosillo, Sonora 83000, Mexico.
authors.forename: Adán
authors.initials: A
authors.lastname: Valenzuela-Castillo
authors.affiliation: Centro de Investigaciones Biológicas del Noroeste S.C. Laboratorio de Referencia, Análisis y Diagnóstico en Sanidad Acuícola, Hermosillo, Sonora 83106, Mexico.
authors.forename: Arturo
authors.initials: A
authors.lastname: Sánchez-Paz
authors.affiliation: Universidad de Sonora, Departamento de Investigaciones Científicas y Tecnológicas, Hermosillo, Sonora 83000, Mexico.
authors.forename: Reina
authors.initials: R
authors.lastname: Castro-Longoria
authors.affiliation: Universidad de Sonora, Departamento de Investigaciones Científicas y Tecnológicas, Hermosillo, Sonora 83000, Mexico.
authors.forename: Marco Antonio
authors.initials: MA
authors.lastname: López-Torres
authors.affiliation: Universidad de Sonora, Departamento de Investigaciones Científicas y Tecnológicas, Hermosillo, Sonora 83000, Mexico. Electronic address: mgrijal@guayacan.uson.mx.
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Grijalva-Chon
mesh_terms: D000818:Animals; D001483:Base Sequence; D049896:Crassostrea / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology*; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics* / Q000378:metabolism; D008800:Mexico; D008969:Molecular Sequence Data; D010802:Phylogeny; D011110:Polymorphism, Genetic; D012621:Seasons; D013696:Temperature
chemical_list: D018840:HSP70 Heat-Shock Proteins
keywords: Aquaculture; Crassostrea gigas; Gene expression; Gulf of California; Pacific oyster; hsp70