PRDM9, a driver of the genetic map

Area of Science:

• Genetics and Genomics
• Molecular Biology
• Evolutionary Biology

Background:

• Homologous recombination during meiosis is crucial for fertility and genome evolution, involving exchanges between maternal and paternal chromosomes.
• In many eukaryotes, meiotic recombination hotspots are accessible chromatin regions, but vertebrates exhibit a distinct pattern specified by PR domain-containing protein 9 (PRDM9).

Purpose of the Study:

• To elucidate the mechanisms by which PRDM9 specifies meiotic recombination hotspots in vertebrates.
• To investigate the evolutionary dynamics of PRDM9 and its impact on genome evolution and reproductive isolation.

Main Methods:

• Analysis of PRDM9's distinct activities: DNA binding, histone methyltransferase activity, and protein interactions.
• Investigating the consequences of PRDM9 activity on its own binding sites and DNA-binding domain evolution.
• Examining PRDM9's role in hybrid sterility and potential reduction of activity in heterozygous contexts.

Main Results:

• PRDM9 specifies meiotic recombination hotspots through its multifaceted activities.
• PRDM9 activity leads to the erosion of its own binding sites, driving rapid evolution of its DNA-binding domain.
• PRDM9 is implicated in hybrid sterility, possibly due to altered activity in heterozygous states.

Conclusions:

• PRDM9 is a key determinant of meiotic recombination patterns in vertebrates, impacting fertility and evolution.
• The self-eroding nature of PRDM9 binding sites contributes to rapid evolutionary adaptation.
• PRDM9's role in hybrid sterility highlights its significance in speciation and reproductive isolation.