Description
TitleNext generation sequencing to study organelle genome structure and function
Date Created2015
Other Date2015-10 (degree)
Extent1 online resource (ix, 131 p. : ill.)
DescriptionI utilized next generation sequencing in three separate studies to study organelle genome structure and function in maize, tobacco and barrel medic. In the first study, I found cell-to-cell movement of mitochondria through a graft junction in an experiment designed to select for chloroplast transfer from Nicotiana sylvestris into N. tabacum cells. Flowers of N. tabacum are cytoplasmic male sterile (CMS) due to a sterility-causing mitochondrial genome, thus, N. sylvestris mitochondrial DNA transfer was recognized by restoration of flower fertility. Extensive recombination of mitochondrial genome sequences was revealed in a graft regenerant with fertile flowers, linking male sterility to a mitochondrial gene causing homeotic conversion of anthers (hca). Cell-to-cell movement of mitochondrial DNA could enable introduction of male-sterility causing sequences into graft compatible species, and could be used to create novel forms of CMS in species where it does not exist. In the second study, I sequenced and compared the plastid genomes of three fertile and three CMS maize lines: cms-C, cms-S, and cms-T. The plastid genomes were found to harbor little diversity. I also report that 27 cms-T accessions representing five independently isolated lines have the same diagnostic plastid SNPs. This indicates a single origin and maternal co-transmission of the cms-T mitochondria and plastids to the seed progeny, excluding exceptional pollen transmission of mitochondria or multiple horizontal gene transfer events as the source of the CMS-causing gene. In the third study, I found two distinct plastid genome configurations in Medicago truncatula. I sequenced and assembled the plastid genome of four accessions, three of which belong to ssp. truncatula, and the fourth, R108, to ssp. tricycla. R108 plastid DNA had a ~45-kb inversion compared to ssp. truncatula, mediated by a short, imperfect repeat. DNA gel blot analyses of seven additional ssp. tricycla accessions detected only one of the two alternative genome arrangements. Furthermore, a variable number of repeats was found in the essential accD and ycf1 coding regions. accD length was distinct in ten M. truncatula ecotypes, ranging between 650 and 796 amino acids. Thus, intra-species plastid genome variability in M. truncatula could be linked to repeat-mediated genome rearrangements.
NotePh.D.
NoteIncludes bibliographical references
Noteby Csanad Gurdon
Genretheses, ETD doctoral
Languageeng
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.
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