关键词: 鲤, 硬酯酰辅酶A脱氢酶, 低温, 荧光定量PCR

Abstract: The gene of stearoyl-CoA Desaturase(SCD) as a rate limiting enzyme involved in desaturation of saturated fatty acids plays vital roles in maintaining membrane fluidity and is considered as a key candidate which helps to improve cold tolerance.A SCD cDNA from common carp(Cyprinus carpio)(CcSCD) brain at cooling temperature was characterized and the transcription expression profiles were examined in the common carp exposed to cold(6℃) and warm(23℃) temperatures using real time RT-PCR.A full-length CcSCD cDNA was shown to be comprised of 2618 bp,including an open reading-frame of 975 bp and deduced 324 amino acid residues.Phylogenetic analysis revealed that the SCD protein sequences of the common carp and grass carp(Ctenopharyngodon idella) were clustered together,sharing the highest level of similarity(88%).The quantified results showed that under cooling temperature,CcSCD transcripts were significantly up-regulated(P〈0.01),in comparison to transcripts of samples from normal temperature.The findings help to establish a transgene construction and to apply genetic manipulation to identify functions of CcSCD gene of fish during cold response in future.

Key words: common carp, Stearoyl-CoA Desaturase(SCD), cooling temperature, qRT-PCR