Cloning and characterization of cDNAs for 70-kDa heat-shock proteins(Hsp70) from two fish species of the genus Oryzias.

Abstract

cDNA corresponding to two hsp70-related genes (OLHSC70 and CEHSC70) were isolated from two lines of cultured fish cells derived from the genus Oryzias. OLHSC70 was 2,261 bp in length and encoded a protein of 686 amino acids with a predicted molecular mass of 76,120 daltons. CEHSC70 was 2,114 bp in length and it lacked the 5' region found in OLHSC70. Two-dimensional electrophoresis revealed that Oryzias latipes has at least three heat-inducible proteins with molecular masses of about 70,000 daltons. One of these proteins (Hsp70.1) was barely expressed under normal conditions but its high-level expression was induced by hyperthermia. The other two proteins (Hsc70.1, and Hsc70.2) were constitutively expressed under normal conditions and only slightly enhanced levels were induced by hyperthermia. Transfection with the cloned sequence, RNA dot-blot analysis and the two-dimensional electrophoresis of proteins showed that OLHSC70 encoded Hsc70.1.

Are hsps suitable for indicating stressed states in fish?

“…Since most of the hsp genes do not contain introns, the mRNA is rapidly translated into nascent proteins within minutes of exposure to a stressor. Genomic sequences for hsp70 are being elucidated in fish, including rainbow trout (Oncorhynchus mykiss; Kothary et al, 1984), medaka (Oryzias latipes; Arai et al, 1995), zebrafish (Lele et al, 1997), pufferfish (Fugu rubripes; Lim and Brenner, 1999) and tilapia (Oreochromis mossambicus; Molina et al, 2000).…”

Differential expression of three Paralichthys olivaceus Hsp40 genes in responses to virus infection and heat shock☆

“…So far, some Hsp genes have been cloned in different fish species, including Hsp70 from rainbow trout [25,26], medaka [27], zebrafish [28], tilapia [29] and pufferfish [30], Hsp90 from Chinook salmon [31] and Atlantic salmon [32], and several low molecular weight Hsps, including DnaJ homologues [25]. Heat shock is capable of inducing fish cells to increase the expression of Hsps [33].…”

Effects of GH, prolactin and cortisol on hepatic heat shock protein 70 expression in a marine teleost Sparus sarba

“…Furthermore, the application of molecular biology techniques to fish HSP studies has been used for several species. For example, a constitutively expressed heat shock cognate gene from Oncorhynchus mykiss testes (Zafarullah et al 1992), two HSP70-related genes from the cell lines OLHSC70 and CEHSC70 of Oryzias latipes and Oryzias celebensis respectively (Arai et al 1995), and an HSP70 from a long-term leucocyte cell line of Ictalurus punctatus (Luft et al 1996) have been cloned and characterised. Although all of the aforementioned studies have provided valuable and interesting knowledge on the biology of piscine HSP, the endocrine regulation of HSP expression in fish remains to be elucidated.…”