|其他摘要||Bioinformatics sets the organism genome sequence information as the beginning of analysis, it aims to break the DNA genetics information which is hidden in the DNA sequence, especially noncoding area of the chromosome. While, after finding the new gene information, it starts to simulate and predict the protein space structure. Heat shock protein 70 is a kind of particular responsive protein which is induced by high temperature and other stress environments. Its substantial expression can alter the survival ability of organisms, which improve the tolerance of organisms to environmental stress. Syntrichia caninervis and Bryum argenteum are typical desert moss species. Although their morphology is rather simple, they can survive in an extremely drought, high or low temperature environment. Its preeminent genetics resource ensures these species to be a hot research field. Based on RNA-seq technology, we got the global transcriptome of those two mosses during the course of dehydration and rehydration. By utilizing HSP70 Hidden Markov Model probability model provided by Pfam database and HMMER software, we acquired HSP70 gene family member sequence from 2 mosses transcriptome database, and then conducted the bioinformatics analysis and gene expression pattern.
The main results were as follows:
(1)By using TRINITY software, the transcriptome raw reads were assembled and then annotated. We acquired 37 ScHSP70s and 33 BaHSP70s with more than 200bp length in Syntrichia caninervis and Bryum argenteum separately, from the transcriptome database proposed by HSP70 Hidden Markov Model probability model.
(2) All the ScHSP70s sequences didn’t contain complete opening reading frame (ORF). Evolution analysis showed sequences with high similarity belonged to the same sub-family and could be separated into three parts, DnaK Subfamily, Hsc70 Subfamily and Hsp 110/SSE Subfamily. So as to B. argenteum, only 2 of BaHSP70s contained complete ORF. Multiple sequence alignment analysis indicated that the loci from 120aa to 190aa were conserved, and two extended strand and only one alpha helix located in the
Nucleotide Binding Domain. Evolution analysis showed sequences with high similarity belonged to the same sub-familyseparated all the sequence into three part, DnaK Subfamily, Hsc70 Subfamily, Hsp 110/SSE Subfamily.
(3) We conducted bioinformatics analysis of the two BaHSP 70 with complete ORF from the aspect of amino acid component, conserved domain, physicochemical property, hydrophobicity and hydrophily, signal peptide, protein structure, motif recognition, homologous analysis. The result showed that the length of two BaHSP70s are 649aa and 650aa, respectively. The corresponding transcripts in the transcriptome database is 2396bp and 2356bp. Sequence motif analysis indicates that there were 5 identical motif consistent for all selected species. multiple sequence alignment and homologous analysis demonstrates that BaHSP70s are most closely related to Saussurea, reaching to the identity of 91.2%.
(4) Quantitative reverse transcription PCR research experiment shows: the expression pattern of each Bryum argenteum Heat Shock Protein 70 gene family member is distinctive under the environment stress of drought and rehydration. There are seven genes represent downtrend, 5 of them expressed highly in the process of rehydration. The result indicates that CL412.Contig2, CL2786.Contig2, Unigene12388, Unigene32646, Unigene32739 genes are excellent candidate genes in the following research of stress resistance gene cloning.|