Molecular characterization of Chaetomium species using URP-PCR

Chaetomium spp. are common colonizers of soil and cellulose-containing substrates. Seventeen isolates of Chaetomium spp., which included 15 isolates of C. globosum and one each of C. reflexum and C. perlucidum , were genetically characterized with universal rice primers (URP - primers derived from DNA repeat sequences in the rice genome) using polymerase chain reaction (URP-PCR). Out of the 12 URP's used in the study, nine primers were effective in producing polymorphic fingerprint patterns from DNA of Chaetomium spp . Analysis of the entire fingerprint profile using the unweighted pair-group method with arithmetic averages (UPGMA) clearly differentiated C. globosum isolates from C. perlucidum and C. reflexum . One of the primers, URP-2R, produced a uniform DNA band of 1.9 kb in all the isolates of C. globosum but not in C. perlucidum and C. reflexum , which can be used as molecular marker to differentiate C. globosum from other species. Our results indicate that URP's are sensitive and give reproducible results for assaying the genetic variability in Chaetomium spp

Phylogenetic relationships of Chaetomium isolates based on the internal transcribed spacer region of the rRNA gene cluster

Molecular characterization of 18 Chaetomium isolates collected from India based on the internal transcribed spacer (ITS) region of the rRNA gene sequences was done. Phylogenetic analysis of full length ITS region showed that Chaetomium globosum isolates, Cg1, Cg2, Cg6, Cg11 and Cg15, Chaetomium spp. isolates, C16, C17 and a Chaetomium perlucidum isolate formed a group with American isolates of Chaetomium spp., SW287, SW271 and CL024, thereby supporting the close relationships among these isolates. Other C. globosum isolates, Cg3, Cg4, Cg5, Cg10, Cg12, Cg13 and Cg14 clustered with European isolates, UOA/HCPF 9215 and UOA/HCPF 9860 and an Australian isolate NC1. Isolates Cg7, Cg8, and Cg9 were closely related to the Australian isolates but distantly related to the isolates from New Zealand. However, all these isolates clustered in the same Australia group as evident in the evolutionary history analysis using parsimony method. European isolate MU-2009 and Australian isolates NA26 were separated from the rest of the isolates and did not cluster in any of the groups formed. Results indicate that, different isolates of the Chaetomium spp. may have different life strategies and specialized in surviving diverse climates.Keywords: Chaetomium, rRNA sequences, internal transcribed spacer (ITS), phylogenyAfrican Journal of Biotechnology Vol. 12(9), pp. 914-92