Studies On CDNA Encoding A Kind Of Heat Shock Proteins 70 (HSP70) In Shrimps Fenneropenaeus Chinensis And Litopenaeus Vannamei

The p70 cDNA of 2090 base pairs was cloned by RT-PCR method from the hepatic tissues of Chinese shrimp (Fenneropenaeus chinensis) after the animals were integrating heat shocked. The primers used for PCR were designed based on the hsp70 ESTs sequence from the Chinese shrimp EST database kept in our laboratory. The hsp70 cDNA we cloned included the complete CDS of 1956 base pairs and partial sequence of 5'UTR and 3'UTR. The results of PCR and sequencing showed that the hsp70 may contained intron(s) in the position of the 1~547 bp sequence of cDNA, and there is no intron in the position of the 548~2090 bp sequence. The duduced 652 amino acids from CDS showed high identity with the HSP70 family from other eukaryotes, 85.9% identity with Oncorhynchus mykiss IISC71 and Homo sapiens HSC70, 85.8% identity with Mux musculus IISP70, and 85.4% identity with Manduca Sexta HSC70.The sequence of hsp70 cDNA from Lilopenaeus vannamei was also defined in this study. There was 97% nucleic acids similarity between hsplQ cDNA from the two kinds of shrimps and 60 base pairs differences. Most of the base pairs difference within the CDS did not change the amino acidsencoded. The amino acids identity was 99.8% and there was only one difference among the 652 amino acids. The amino acid of 483 was serine in Fenneropenaeus chinensis, while it was asparagines instead in Litopenaeus vannamei. The amino acid difference occurred in the peptides-binding domain of HSP70. These results showed that hsp70 is highly conserved in shrimps.Semi-quantitative RT-PCR was developed to study the hsp70 transcription pattern in Fenneropenaeus chinensis. The transcription of hsp70 was detected in the major tissues of hepatopancreas, muscles, eyestalks under both normal and heat shocked conditions .The mRNA level was increased after the animals were heat shocked in the 3 tissues. The mRNA level in muscles of shrimps held at heat shock temperature for 7 days was higher than that at normal temperature.The hsp70 transcriptions in Fenneropenaeus chinensis challenged with Vibrio anguillavhim and WSSV were also studied. The hsp70 mRNA level in the hepatopancreas of agonal shrimps infected with WSSV by feeding was lower remarkably than that of normal shrimps, while no rule of hsp70 transcription was discovered in muscles of shrimps infected with Vibrio anguillavium and WSSV for different hours by injection. The hsp70 mRNA level was detected in the whole body of shrimps which were P11 of juveniles or more than 3 months old shrimp, the results showed that the hsp70 mRNA was tend to decrease in this developing period of Chinese shrimps.