Truncated and RIP-degenerated copies of the LTR retrotransposon Pholy are clustered in a pericentromeric region of the Leptosphaeria maculans genome

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• 作者：Attard ; Agn??s ; Gout ; Lilian ; Ross ; Simon ; Parlange ; Francis ; Cattolico ; Laurence ; Balesdent ; Marie-H??l??ne ; et. al.
• 关键词：Avirulence ; Phoma lingam ; Brassica napus ; AvrLm1 ; copia/Ty1 ; Centromere
• 刊名：Fungal Genetics and Biology
• 出版年：2005
• 出版时间：January, 2005
• 年：2005
• 卷：42
• 期：1
• 页码：30-41
• 全文大小：708 K

文摘

The LMR1 5.2kb interspersed repeat of Leptosphaeria maculans was described by Taylor and Borgmann [Mol. Plant Microbe Interact. 7 (1994) 181] as an uncharacterized repeated element sharing homologies with both LINEs and SINEs. Here, we used the LMR1 sequence as a template to identify the full-length element within a 184-kb genomic sequence corresponding to the pericentromeric region of the 2.80Mb chromosome of isolate v23.1.3. This region comprises (i) one 6980-bp full-sized Pholy element bordered by two 275- to 280-bp long terminal repeats (LTRs), (ii) five Pholy-related sequences, usually truncated at their 3aaa ends, and (iii) five solo-LTRs. Structural features strongly suggested that Pholy corresponds to an ancient copia-like retrotransposon, sharing strong homologies with the Elsa retrotransposon of Stagonospora nodorum. Pholy was also suggested to be specific to pericentromeric regions. Comparative analysis of the structure of the Pholy-like sequences occurring in the 184-kb contig and in other parts of the genome showed that this family of repeats is highly degenerated following extensive repeat induced point mutation (RIP).