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Updated: Aug 9, 2026

Discrimintion and Mapping of the Primary and Processed Transcripts in Maize Mitochondrion Using a Circular RT-PCR-based Strategy
07:26

Discrimintion and Mapping of the Primary and Processed Transcripts in Maize Mitochondrion Using a Circular RT-PCR-based Strategy

Published on: July 29, 2019

Unique DNA associated with mitochondria in the "S"-type cytoplasm of male-sterile maize

D R Pring1, C S Levings, W W Hu

  • 1Agricultural Research Service, U.S. Department of Agriculture, Department of Plant Pathology, University of Florida, Gainesville, Florida 32611.

Proceedings of the National Academy of Sciences of the United States of America
|July 1, 1977
PubMed

Insights

Researchers identified unique mitochondrial DNAs in S cytoplasm maize, potentially confirming an episomal system. This finding offers new insights into male-sterile cytoplasm genetics.

Area of Science:

  • Plant genetics
  • Molecular biology
  • Mitochondrial genetics

Background:

  • Male-sterile cytoplasms in maize (Zea mays) are crucial for hybrid seed production.
  • Understanding the genetic basis of male sterility is key to improving crop yields.
  • Mitochondrial DNA (mtDNA) plays a significant role in cytoplasmic male sterility (CMS).

Purpose of the Study:

  • To investigate the molecular characteristics of mitochondrial DNA in various maize cytoplasms.
  • To identify any unique DNA components associated with the S cytoplasm male-sterile trait.

Main Methods:

  • Mitochondrial DNA was isolated from maize lines with normal and different male-sterile cytoplasms (T, C, S, EP).
  • Agarose gel electrophoresis was used to analyze the mtDNA.
  • Electron microscopy was employed to examine the unique DNA structures.

Main Results:

  • All maize cytoplasms showed a main high-molecular-weight mtDNA band.
  • The S cytoplasm uniquely contained two additional faster-migrating DNA molecules (approx. 3.4-3.5 x 10^6 and 4.0-4.1 x 10^6 molecular weight).
  • Electron microscopy indicated these unique S-cytoplasm DNAs varied in length but lacked clear molecular configuration.

Conclusions:

  • The presence of unique mtDNA molecules in S cytoplasm provides physical evidence for a previously hypothesized episomal system.
  • These findings contribute to understanding the molecular mechanisms underlying S cytoplasm male sterility in maize.
  • Further research is needed to elucidate the structure and function of these unique maize mitochondrial DNAs.

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