草菇gpi基因结构及其异核体表达协同增效作用

Volvariella volvacea Glucose-6-phosphate Isomerase Gene(gpi) Model and Synergistic Gene Expression in a Hybrid Heterokaryon

以草菇(Volvariella volvacea)单孢菌株PYd21(基因组测序菌株)和PYd15(基因组重测序菌株)为材料,配对获得可正常出菇的异核菌株H15-21。克隆测序了PYd21和PYd15的葡萄糖-6-磷酸异构酶基因(gpi),并对基因的结构和表达谱的表达量进行分析。结果表明,PYd21和PYd15的gpi基因序列相同;转录组reads定位、paired-end分析结果显示,gpi基因全长2404bp,ORF全长1659bp,编码552个氨基酸,含有8个外显子、7个内含子,5'UTR长度为101bp、3'UTR为183bp,RNA加工过程中有2种可变剪切类型、3个可变剪接位点;表达谱测序结果,PYd21、H15-21和PYd15 gpi基因的表达量分别为84.53、1079.31和270.95TPM,草菇gpi基因表达表现出异核体表达协同增效作用,暗示着异核菌株中的2种不同来源的细胞核可能存在相互作用,这一结果在实时荧光定量PCR检测后得到证实。

A hybrid heterokaryon,H15-21,was obtained by mating two single spore isolates,PYd21 and PYd15,the genomes of which were sequenced by de novo sequencing and re-sequencing,respectively.Glucose-6-phosphate isomerase genes（gpi） were cloned and sequenced from both PYd21 and PYd15,and their structures were analyzed through transcriptional read and paired-end mapping.Alignment revealed both sequences to be identical,and that gpi consisted of 2404 bp with an open reading frame（ORF） of 1659 bp encoding a polypeptide of 552 amino acids.Gpi contained 8 exons and 7 introns,and the 5＇ UTR and 3＇ UTR were 101 bp and 183 bp long,respectively.Two types of alternative splicing and three alternative splicing sites were identified during RNA processing.TPM（number of tags mapped only from gpi ×1000000/ total number of tags） values for PYd21,PYd15 and H15-21 were 84.53,270.95 and 1079.31 respectively,which indicated that the two nuclei（from PYd21 and PYd15） in H15-21 interacted synergistically with each other.Digital gene expression profiling and real-time quantitative PCR,used to measure gpi gene expression levels in the three strains,confirmed this effect.