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United States Department of Agriculture

Agricultural Research Service

Research Project: CONTROL AND PROTECTION TOOLS FOR INTEGRATED PEST MANAGEMENT OF MOSQUITOES AND FILTH FLIES

Location: Mosquito and Fly Research Unit

Title: Mutations in nuclear genes alter post-transcriptional regulation of mitochondrial genes.

Authors
item Kamps, Terry - UNIVERSITY OF FLORIDA
item Zhao, Liming
item Chamusco, Karen - UNIVERSITY OF FLORIDA
item Read, Victoria - UNIVERSITY OF FLORIDA
item Anderson, Ashley - UNIVERSTIY OF FLORIDA
item Hannah, Curtis - UNIVERSITY OF FLORIDA
item Mccarty, Donald - UNIVERSITY OF FLORIDA
item Gabay-Laughnan, Susan - UNIVERSITY OF ILLINOIS
item Chase, Christine - UNIVERSITY OF FLORIDA

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 27, 2008
Publication Date: N/A

Technical Abstract: Nuclear gene products are required for the expression of mitochondrial genes and elaboration of functional mitochondrial protein complexes. To better understand the roles of these nuclear genes, we exploited the mitochondrial encoded S-type of cytoplasmic male sterility (CMS-S) and developed a novel collection of nuclear mutations affecting mitochondrial functions in maize. These mutations gametophytically restore fertility function to the pollen of CMS-S plants. Although the restorer mutations rescue CMS-S pollen, many are homozygous lethal for maize kernel development and might, therefore, disrupt essential mitochondrial functions. for our nine molecularly characterized CMS-S restorers, genetic complementation testing indicates allelism between only a spontaneous rfl2 mutant and one recovered form a transposon tagging population. We have profiled the transcripts and protein products of mitochondrial genes in developmentally staged pollen from those CMS-S restorer lines and an isogenic MO17 line having normal cytoplasm with no restorer genes. The profiles revealed that five restorer mutations conditioned global loss of mitochondrial gene products through post-transcriptional mechanisms. These mutants must therefore control mitochondrial protein accumulation via other post-transcriptional processes. We further tested this mechanism by examining RNA editing, a post-transcriptional feature of plant mitochondrial gene expression. The editing pattern of the maize mitochondrial atp6 gene was first determined by sequence analysis of atp6 RT-PCR products from microspores of non-restorer carrying normal and CMS-S cytoplasm isogenic lines. A high frequency of RNA editing caused codon changes, as well as the generation of several new restriction enzyme recognition sites. Restriction enzyme analysis of the atp6 RT-PCR products demonstrated that RNA editing generated the three sequencing predicted cleaved amplified polymorphism (CAPs)sites in the developing pollen of all our CMS-S restorer.

Last Modified: 8/21/2014