Kang S
Department of Plant Pathology, The Pennsylvania State University, 311 Buckhout Laboratory, University Park, Pennsylvania 16802, USA.
Fungal Genet Biol. 2001 Feb;32(1):11-9. doi: 10.1006/fgbi.2000.1246.
A specific telomere was deleted in spontaneous, gain-of-virulence mutants derived from a rice pathogen of Magnaporthe grisea. Three different types of transposons, including Pot2, Mg-SINE, and a novel, 6-kb-long LTR (long terminal repeat)-type retrotransposon designated MGLR-3, were identified on this chromosomal end. The 114-bp-long telomeric repeat is immediately followed by the 3' LTR of MGLR-3. A truncated copy of Pot2 immediately flanks the 5' LTR, suggesting that this telomere was generated by a transposition event of MGLR-3 into this Pot2 element, causing the breakage of a chromosome. The subsequent addition of a telomeric repeat to the 3' LTR of MGLR-3 most probably repaired the broken end of the chromosome. Mg-SINE is located 25 bp away from the truncated Pot2 element. MGLR-3 exhibited strong homology to various gypsy-class retrotransposons, including grh and MAGGY in M. grisea. MGLR-3 is ubiquitous regardless of the host of origin.
在源自稻瘟病菌这一水稻病原体的自发毒力增强突变体中，一个特定的端粒被删除。在这个染色体末端鉴定出了三种不同类型的转座子，包括Pot2、Mg-SINE以及一种新型的、6千碱基对长的长末端重复（LTR）型逆转座子，命名为MGLR-3。114碱基对长的端粒重复序列紧接着MGLR-3的3' LTR。Pot2的一个截短拷贝紧邻5' LTR，这表明这个端粒是由MGLR-3转座到这个Pot2元件中产生的，导致了一条染色体的断裂。随后在MGLR-3的3' LTR上添加端粒重复序列很可能修复了染色体的断裂末端。Mg-SINE位于距截短的Pot2元件25碱基对处。MGLR-3与各种吉普赛类逆转座子表现出很强的同源性，包括稻瘟病菌中的grh和MAGGY。无论起源宿主是什么，MGLR-3都普遍存在。
