Journal of Nematology (2005) 37, p. 373 (Hyman et al.)

B.C. Hyman, S. Tang, Z. Wu, E.G. Platzer and R. Pacheco (2005)
Haplotype hypervariation and rampant gene rearrangement shape mermithid nematode mitochondrial genome organization
Journal of Nematology 37 (3), 373-373
44th Annual Meeting, Society of Nematologists, Fort Lauderdale, Florida, 9-13 July, 2005
Abstract: Rare syntenic conservation, sequence duplication, and the use of both DNA strands to encode genes are signature architectural features defining mitochondrial genomes of Enoplea. To address the frequency of gene rearrangement within nematode mitochondrial DNA(mtDNA), we are studying mitochondrial genome variation within a more confined taxonomic unit, the family Mermithidae. The complete nucleotide sequences of the mosquito parasitic nematodes Romanomermis culicivorax, R. nielseni, and R. iyengari mtDNA have been determined. Duplicated expanses encompassing different regions of the mitochondrial genomes were found in each of these congeners. These mtDNA shared only four to seven rRNA and protein gene junctions, indicating extensive gene rearrangement within the Romanomermis lineage. The few conserved gene clusters are likely ancestral and facilitate prediction of progenitor gene orders and genetic mechanisms leading to the complex, contemporary transcriptional organization of Romanomermis mtDNA. Rapid structural changes are also observed at the conspecific level. Rolling circle amplification was used to isolate complete mitochondrial genomes from individuals in local populations of Thaumamermis cosgrovei, a terrestrial isopod parasite. Mitochondrial DNA length variants ranging from 19 to 34 kb are observed. The complete nucleotide sequences of two haplotypes have been determined, revealing a.constant region encoding most mitochondrial genes and a hypervariable segment between the ATPase 6 and the 16S rRNA coding sequences. The hypervariable locus contains intact and truncated copies of several mitochondrial genes, duplicated to different copy numbers, resulting in mtDNA size variation. Unique haplotypes propagated at geographically distant sampling locations suggests that constant mutation generates new T. cosgrovei mtDNA forms.
Database assignments for author(s): Edward G. Platzer

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
Romanomermis culicivorax (entomopathogen)
Romanomermis iyengari (entomopathogen)