ISHS Acta Horticulturae 706: IV International Symposium on Brassicas and XIV Crucifer Genetics Workshop
SEQUENCE ANALYSIS OF TWO GENOMIC REGIONS OF LEPTOSPHAERIA MACULANS, THE FUNGUS THAT CAUSES BLACKLEG DISEASE (PHOMA STEM CANKER) OF BRASSICA NAPUS |
| Authors: | B.J. Howlett, D.M. Gardiner, A.J. Cozijnsen, L.M. Wilson, L. Cattolico, M. Soledade, C. Pedras, C. Pedras, T. Rouxel, A. Attard, L. Gout, F. Parlange, S. Ross, M.H. Balesdent |
| Keywords: | transposon, fungal genome, gene cluster, sirodesmin |
| Abstract:
The dothideomycete fungus, Leptosphaeria maculans, is poorly described at the genomic level. Two genomic regions have been analysed - one (55 kb) comprises a cluster of 18 genes encoding the biosynthetic enymes for a phytotoxin, sirodesmin, whilst the other (184 kb) is the pericentromeric region of a 2.80 Megabase chromosome. Transcription of all genes in the sirodesmin gene cluster is co-regulated with the production of sirodesmin in culture. Disruption of one of these genes (encoding a two-module non-ribosomal peptide synthetase) is essential for production of sirodesmin. The 184 kb sequence contains 6.980 kb repetitive element named Pholy bordered by two Long Terminal Repeats (LTRs), five Pholy-related sequences, mostly truncated at their 3’ ends; and five solo-LTRs. This element, Pholy, comprises a previously described element, LMR1. Structural features suggest that Pholy corresponds to an ancient copia-like retrotransposon, as it has high sequence similarity to the ELSA retrotransposon of the closely related fungus, Stagonospora nodorum. Comparative analysis of the structure of the Pholy-like sequences in the 184 kb contig and in other parts of the genome suggests that this family of repetitive elements has undergone extensive Repeat Induced Point (RIP) mutation. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
