Cloning and characterization of the calreticulin gene in Asian seabass (Lates calcarifer)

Abstract

Calreticulin (CRT) is a Ca 21 -binding molecular chaperone in the endoplasmic reticulum. We cloned and characterized the CRT gene in an important marine food fish species Asian seabass (Lates calcarifer). The full-length DNA of the CRT gene was 2194 bp, including a complete open reading frame encoding 420 amino acid residues, a 113 bp 5 0 -untranslated region and an 818 bp 3 0 -untranslated region. The CRT gene contained nine exons and eight introns covering a total of 2772 bp genomic DNA from the start to stop codon. Ten single nucleotide polymorphisms (SNPs) were detected in introns and an exon in six individuals collected from five different locations. The CRT gene was assigned to linkage group 4 of the linkage map of Asian seabass. Quantitative real-time PCR revealed that the CRT gene was highly expressed in liver at the age of 1, 3 and 7 months under normal conditions, whereas its expression in liver reduced sharply after 0.5 to 2 h cold challenge at 168C, and then increased slowly. A preliminary association analysis showed a significant (P , 0.001) association between the SNP6 in the CRT gene and the mortality after cold challenge at 168C. Our results suggest that the CRT gene is associated with cold tolerance of Asian seabass and further investigation will be necessary to illustrate the underlying mechanisms.Keywords: Barramundi, polymorphism, cold tolerance, QTL ImplicationsWe have isolated the whole length of the complementary DNA of the Calreticulin (CRT ) gene in the Asian seabass, studied the expression levels under normal condition and after 168C cold challenge, analyzed the genomic organization and polymorphism, and identified the association between the single nucleotide polymorphism6 and cold tolerance. Our results suggest that the CRT gene may be involved in cold tolerance in the Asian seabass. Further investigation will be required to illustrate the underlying mechanisms.

Amblyomma americanum tick calreticulin binds C1q but does not inhibit activation of the classical complement cascade

“…Coding cDNAs have now been identified in multiple organisms including ticks (Jaworski et al, 1995, Ferreira et al, 2002, Xu et al, 2004, 2005, Kaewhom et al, 2008, Gao et al, 2008), fleas (Jaworski et al, 1996), nematodes (Smith, 1992, Huggins et al, 1995, Tsuji et al, 1998, Scott et al, 1999, Mendlovic et al, 2004, Cabezón et al, 2008, Li et al, 2011), protozoan parasites (Aguillón et al, 2000, Marcelain et al, 2000, González et al, 2002), fish (Kales et al, 2004, Bai et al, 2012) and plants (Jia et al, 2008, Jin et al, 2009, An et al, 2011). Many more CRT sequences have been deposited in GenBank unpublished as direct submissions.…”

Recent advances of genome mapping and marker‐assisted selection in aquaculture

“…) and Asian seabass (Bai et al . ). The purpose of selecting for salinity and temperature tolerance is to develop fishes that could reproduce and grow in areas of higher salinity and lower/higher temperature.…”

“…The polymorphisms in the calreticulin gene were associated with cold tolerance (Bai et al . ). However, these significant associations must be examined in different families to ascertain whether these associations are family specific or universal.…”

“…) and cold tolerance (Bai et al . ) have been also performed. Polymorphisms in prolactin and parvalbumin genes were associated with growth traits (Xu et al .…”

“…Salinity tolerance and temperature tolerance are two traits of interest for some fish species, such as tilapia (Rengmark et al 2007;Yan and Wang 2010), rainbow trout (Le Bras et al 2011), Arctic charr (Norman et al 2011) and Asian seabass (Bai et al 2012). The purpose of selecting for salinity and temperature tolerance is to develop fishes that could reproduce and grow in areas of higher salinity and lower/higher temperature.…”