摘要
Horizontal gene transfer （HGT） has long been considered as a principal force for an organism to gain novel genes in genome evolution. Homology search, phylogenetic analysis and nucleotide composition analysis are three major objective approaches to arguably determine the occurrence and directionality of HGT. Here, 21 genes that possess the potential to horizontal transfer were acquired from the whole genome of Magnaporthe grisea according to annotation, among which three candidate genes （corresponding protein accession numbers are EAA55123, EAA47200 and EAA52136） were selected for further analysis. According to BLAST homology results, we subsequently conducted phylogenetic analysis of the three candidate HGT genes. Moreover, nucleotide composition analysis was conducted to further validate these HGTs. In addition, the functions of the three candidate genes were searched in COG database. Consequently, we conclude that the gene encoding protein EAA55123 is transferred from Clostridium perfringens. Another HGT event is between EAA52136 and a certain metazoan＇s corresponding gene, but the direction remains uncertain. Yet, EAA47200 is not a transferred gene.
Horizontal gene transfer （HGT） has long been considered as a principal force for an organism to gain novel genes in genome evolution. Homology search, phylogenetic analysis and nucleotide composition analysis are three major objective approaches to arguably determine the occurrence and directionality of HGT. Here, 21 genes that possess the potential to horizontal transfer were acquired from the whole genome of Magnaporthe grisea according to annotation, among which three candidate genes （corresponding protein accession numbers are EAA55123, EAA47200 and EAA52136） were selected for further analysis. According to BLAST homology results, we subsequently conducted phylogenetic analysis of the three candidate HGT genes. Moreover, nucleotide composition analysis was conducted to further validate these HGTs. In addition, the functions of the three candidate genes were searched in COG database. Consequently, we conclude that the gene encoding protein EAA55123 is transferred from Clostridium perfringens. Another HGT event is between EAA52136 and a certain metazoan＇s corresponding gene, but the direction remains uncertain. Yet, EAA47200 is not a transferred gene.
基金
supported in part by grants from the National Natural Science Foundation of China (General Programs No. 30270331 and No. 30670469)
Director Fund of the State Key Laboratory of Oral Diseases (Sichuan University)
the Science and Technology Fund for Distinguished Young Scholars of Sichuan Province (No.06ZQ026-035)
the Key Technologies R&D Program of Sichuan Province (2006Z08-010)
