Genes and processed paralogs co-exist in plant mitochondria

TY - JOUR

T1 - Genes and processed paralogs co-exist in plant mitochondria

AU - Cuenca Navarro, Argelia

AU - Petersen, Gitte

AU - Seberg, Ole

AU - Jahren, Anne Hoppe

PY - 2012/4

Y1 - 2012/4

N2 - RNA-mediated gene duplication has been proposed to create processed paralogs in the plant mitochondrial genome. A processed paralog may retain signatures left by the maturation process of its RNA precursor, such as intron removal and no need of RNA editing. Whereas it is well documented that an RNA intermediary is involved in the transfer of mitochondrial genes to the nucleus, no direct evidence exists for insertion of processed paralogs in the mitochondria (i.e., processed and un-processed genes have never been found simultaneously in the mitochondrial genome). In this study, we sequenced a region of the mitochondrial gene nad1, and identified a number of taxa were two different copies of the region co-occur in the mitochondria. The two nad1 paralogs differed in their (a) presence or absence of a group II intron, and (b) number of edited sites. Thus, this work provides the first evidence of co-existence of processed paralogs and their precursors within the plant mitochondrial genome. In addition, mapping the presence/absence of the paralogs provides indirect evidence of RNA-mediated gene duplication as an essential process shaping the mitochondrial genome in plants.

AB - RNA-mediated gene duplication has been proposed to create processed paralogs in the plant mitochondrial genome. A processed paralog may retain signatures left by the maturation process of its RNA precursor, such as intron removal and no need of RNA editing. Whereas it is well documented that an RNA intermediary is involved in the transfer of mitochondrial genes to the nucleus, no direct evidence exists for insertion of processed paralogs in the mitochondria (i.e., processed and un-processed genes have never been found simultaneously in the mitochondrial genome). In this study, we sequenced a region of the mitochondrial gene nad1, and identified a number of taxa were two different copies of the region co-occur in the mitochondria. The two nad1 paralogs differed in their (a) presence or absence of a group II intron, and (b) number of edited sites. Thus, this work provides the first evidence of co-existence of processed paralogs and their precursors within the plant mitochondrial genome. In addition, mapping the presence/absence of the paralogs provides indirect evidence of RNA-mediated gene duplication as an essential process shaping the mitochondrial genome in plants.

KW - Faculty of Science

U2 - 10.1007/s00239-012-9496-1

DO - 10.1007/s00239-012-9496-1

M3 - Journal article

C2 - 22484699

SN - 0022-2844

VL - 74

SP - 158

EP - 169

JO - Journal of Molecular Evolution

JF - Journal of Molecular Evolution

IS - 3-4

ER -