Reduced Crossover Interference and Increased ZMM-Independent Recombination in the Absence of Tel1/ATM

Area of Science:

• Molecular Biology
• Genetics
• Cell Biology

Background:

• Meiotic recombination repairs DNA double-strand breaks (DSBs) into crossovers (COs) or noncrossovers (NCOs).
• Proper CO number and distribution are essential for accurate chromosome segregation and viable gamete formation.
• In budding yeast, most COs depend on ZMM proteins, forming foci at committed sites.

Purpose of the Study:

• To investigate the role of the DNA-damage-response kinase Tel1/ATM in regulating meiotic recombination pathways.
• To understand how Tel1 influences CO formation, interference, and DSB distribution.

Main Methods:

• Whole-genome mapping of recombination products in budding yeast.
• Analysis of recombination in wild-type, tel1Δ, zip3Δ, and tel1Δ zip3Δ mutant strains.
• Quantification and interference analysis of ZMM protein foci (Zip3).

Main Results:

• Lack of Tel1 leads to increased recombination and reduced CO interference.
• Tel1 absence results in a significant proportion of COs occurring through a non-ZMM-dependent pathway.
• Tel1, Sgs1, Zip3, or Msh4 absence alters DSB distribution, indicating Tel1's role in DSB interference.

Conclusions:

• Tel1/ATM kinase limits ZMM-independent meiotic recombination.
• A non-ZMM pathway contributes to CO formation in the absence of Tel1, leading to poor CO interference.
• Tel1 plays a crucial role in DSB interference and regulating DSB distribution during meiosis.