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[The distribution and homology of mitochondrial plasmid-like DNAs in different cucumber varieties]

J Y Li1, Y D Wen, J Fu

  • 1Institute for Molecular Biology, Nankai University, Tianjin 300071, China.

Yi Chuan Xue Bao = Acta Genetica Sinica
|May 2, 2001
PubMed

Insights

Mitochondrial plasmid-like DNA (pC1-pC4) in cucumber varieties shows irregular distribution. Homology suggests pC4 integrated into nuclear DNA before cucumber divergence, with some varieties losing these elements.

Area of Science:

  • Plant molecular biology
  • Genetics
  • Evolutionary biology

Context:

  • Mitochondrial plasmid-like DNAs (pC1-pC4) have been identified in cucumber (Jinyan No. 4).
  • The distribution of these plasmid-like DNAs across 14 cucumber varieties was investigated to understand their prevalence and patterns.

Purpose:

  • To analyze the distribution of four mitochondrial plasmid-like DNAs (pC1-pC4) in different cucumber varieties.
  • To investigate the homology of these plasmid-like DNAs within cucumber and related species, and their relationship with nuclear DNA.

Summary:

  • Plasmid-like DNAs were detected in 5 out of 14 cucumber varieties, indicating irregular distribution.
  • Homology was observed among the same plasmid-like DNA families across varieties. Notably, pC4 showed homology with nuclear DNA in Jinyan No. 4 and seven other varieties, with homologous sequences being repetitive.
  • Homologous sequences to pC4 were also found in towel gourd and pumpkin, suggesting ancient integration into nuclear DNA before cucumber divergence from other cucurbits.

Impact:

  • This research proposes that mitochondrial plasmid-like DNA integrated into the nuclear genome early in cucurbit evolution.
  • The findings suggest that the absence of these elements in some cucumber varieties may be due to evolutionary loss.
  • Provides insights into the dynamic nature of organelle DNA and its interaction with the nuclear genome in plants.

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