Novel telomere-anchored PCR approach for studying sexual stage telomeres in Aspergillus nidulans

PLoS One. 2014 Jun 13;9(6):e99491. doi: 10.1371/journal.pone.0099491. eCollection 2014.

Abstract

Telomere length varies between germline and somatic cells of the same organism, leading to the hypothesis that telomeres are lengthened during meiosis. However, little is known about the meiotic telomere length in many organisms. In the filamentous fungus Aspergillus nidulans, the telomere lengths in hyphae and asexual spores are invariant. No study using existing techniques has determined the telomere length of the sexual ascospores due to the relatively low abundance of pure meiotic cells in A. nidulans and the small quantity of DNA present. To address this, we developed a simple and sensitive PCR strategy to measure the telomere length of A. nidulans meiotic cells. This novel technique, termed "telomere-anchored PCR," measures the length of the telomere on chromosome II-L using a small fraction of the DNA required for the traditional terminal restriction fragment (TRF) Southern analysis. Using this approach, we determined that the A. nidulans ascospore telomere length is virtually identical to telomeres of other cell types from this organism, approximately 110 bp, indicating that a surprisingly strict telomere length regulation exists in the major cell types of A. nidulans. When the hyphal telomeres were measured in a telomerase reverse transcriptase (TERT) knockout strain, small decreases in length were readily detected. Thus, this technique can detect telomeres in relatively rare cell types and is particularly sensitive in measuring exceptionally short telomeres. This rapid and inexpensive telomere-anchored PCR method potentially can be utilized in other filamentous fungi and types of organisms.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Aspergillus nidulans / genetics
  • Aspergillus nidulans / physiology*
  • Chromosomes, Fungal / genetics
  • Fungal Proteins / genetics
  • Gene Knockdown Techniques
  • Meiosis
  • Polymerase Chain Reaction / methods*
  • Telomerase / genetics*
  • Telomere / metabolism*
  • Telomere Homeostasis

Substances

  • Fungal Proteins
  • Telomerase

Grants and funding

This work was supported by a grant from the National Science Foundation (nsf.gov) MCB 0950957 to Karen E. Kirk. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.