Instability of subtelomeric regions during meiosis in Magnaporthe oryzae

摘要

Dynamics of chromosomal ends during meiosis was examined using a tetrad F1 population derived from a cross between Setaria and Triticum isolates of Magnaporthe oryzae. Telomeric fragments were liberated by six restriction enzymes and detected with a telomere probe. Each fragment was assigned to one of the 14 chromosomal ends using chromosome-specific markers. Size shifts and non-Mendelian segregation (4:0, 3:1, 1:3, and 0:4) were frequently observed in these telomeric fragments and were considered to be caused by deletion, insertion, point mutation, and gene conversion. Similar results were obtained in another tetrad F1 population derived from a cross between Oryza and Triticum isolates. These results suggest that subtelomeric regions are unstable during meiosis and are prone to various rearrangements including gene conversion.