The Effect Of Temperature On The Longevity, MnSOD And Hsp70 Gene Expression Of Cysteus Brevisii

Rotifers are an important group of zooplankton,which is quite sensitive to changes in the environment,so it is often used to study the impact of environmental change on aquatic ecosystems.In this paper we selected Asplanchna brightwelli as material to study the effect of temperature on its growth and reproduction.We cloned two kinds of Asplanchna brightwelli MnSOD gene with full-length further,and then detected mRNA expression levels of mitochondrial MnSOD,cytoplasmic MnSOD and hsp70 in different temperatures by real time quantitative PCR.We attempt to study the influence of temperature on Asplanchna brightwelli growth and development in traditional ecology and molecular ecology and to explore the role of these genes.This paper included the following three aspects:1.Effect of temperature on the Asplanchna brightwelli life and reproductionTemperature has a significant impact on Asplanchna brightwelli growth and reproduction.As the temperature increased,the average life expectancy,generation interval,pre-reproductive,reproductive,reproductive became shorter;average offspring reduced significantly(P<0.05)only when treated 37 ?(9.3±2.5)and there is no significant difference among 15 ?,30 ? and Control group(25 ?,13.7±2.7).2.Gene clone of Asplanchna brightwelliDegenerate primers were designed with reference to gene sequences of mitochondrial and cytoplasmic MnSOD from other species.Obtain the full sequence of cDNA encoding mitochondrial MnSOD and cytoplasmic MnSOD after confirmed the PCR amplified fragment.The full length of mitochondrial MnSOD gene is 918bp and its open reading frame ORF is 681bp,encoding 226 amino acids.The protein molecular weight 25.2KDa.It is a mitochondrial protein because of no signal peptide predicred.The full length cytoplasmic MnSOD gene is 941 bp and its open reading frame ORF is 705bp,which encoding 234 amino acids.The protein molecular weight 26.1KDa.It is a cytoplasmic protein because of the signal peptide predicted.3.Effects of temperatures on Asplanchna brightwelli MnSOD and hsp70 gene expressionQuantitative real-time PCR showed that both two kinds of MnSOD gene was restored to normal levels after a contemporary increase in lower temperature(15 ?);the expression of the two kinds of MnSOD were gradually increased and reached a significant level at 3h(P<0.05)and remained relatively higher level in 30 ? treatment;the mitochondrial MnSOD did not change significantly while the cytoplasm MnSOD has been maintained at high levels(P<0.05)in 37 ? group.In 15 ??the expression level of hsp70 mRNA increased gradually and reached the maximum after 2h exposed;when exposed to 30 ?,expression of hsp70 mRNA increased 2 times to control group after 0.5 h(P<0.05),which reached the maximum;when treated at 37 ?,hsp70 mRNA expression level increased gradually reached a maximum at 3 h.