Selection of Orthologous Genes for Construction of a Highly Resolved Phylogenetic Tree and Clarification of the Phylogeny of Trichosporonales Species.

The order Trichosporonales (Tremellomycotina, Basidiomycota) includes various species that have clinical, agricultural and biotechnological value. Thus, understanding why and how evolutionary diversification occurred within this order is extremely important. This study clarified the phylogenetic relationships among Tricosporonales species. To select genes suitable for phylogenetic analysis, we determined the draft genomes of 17 Trichosporonales species and extracted 30 protein-coding DNA sequences (CDSs) from genomic data. The CDS regions of Trichosporon asahii and T. faecale were identified by referring to mRNA sequence data since the intron positions of the respective genes differed from those of Cryptococcus neoformans (outgroup) and are not conserved within this order. A multiple alignment of the respective gene was first constructed using the CDSs of T. asahii, T. faecale and C. neoformans, and those of other species were added and aligned based on codons. The phylogenetic trees were constructed based on each gene and a concatenated alignment. Resolution of the maximum-likelihood trees estimated from the concatenated dataset based on both nucleotide (72,531) and amino acid (24,173) sequences were greater than in previous reports. In addition, we found that several genes, such as phosphatidylinositol 3-kinase TOR1 and glutamate synthase (NADH), had good resolution in this group (even when used alone). Our study proposes a set of genes suitable for constructing a phylogenetic tree with high resolution to examine evolutionary diversification in Trichosporonales. These can also be used for epidemiological and biogeographical studies, and may also serve as the basis for a comprehensive reclassification of pleomorphic fungi.

Hepatocyte growth factor (HGF) as a rapid diagnostic marker and its potential in the prevention of acute renal rejection.

Several investigators have reported that hepatocyte growth factor (HGF) may be related to the protection or reconstruction of the kidney during acute renal rejection. To address this question, we examined the relationship between HGF and acute rejection in the following two studies with rat renal transplantation models. In study 1, the relationship between serum HGF levels and acute renal rejection in iso-, allo- and allograft with cyclosporine (CsA)-treated models was examined. In study 2, the focus was whether or not the injection of recombinant HGF can prevent acute renal rejection. Our results demonstrated that HGF levels were rapidly increased during acute rejection and that recombinant HGF effectively protected the kidney from acute rejection. These results suggest that HGF may be induced as a counter-response to the renal injury and that it can be used as a reliable indicator for the diagnosis of acute rejection. We suggest that recombinant HGF suppresses the onset of the pathological changes of acute rejection.