The Baker Lab explores the genetic and molecular regulatory system controlling the location and rate of meiotic recombination, the process that generates new genetic variation in sexually reproducing organisms. In eukaryotes, DNA is wrapped around histones to form nucleosomes, the basic unit of chromatin. Control of chromatin is essential for normal cellular and developmental biology, reproduction, and fundamental to our very understanding of genetics. Because genetic information occurs in chromatin, accessing DNA for gene regulation, replication, recombination, and repair requires precise control of nucleosome remodeling. Aberrations in remodeling and chromatin accessibility can lead to severe developmental disorders, infertility, and cancer.
In a paper in Genes & Development, Assistant Professor Chris Baker led a team that shows two proteins, PRDM9 and HELLS, form a complex that binds to hot spots and opens the site to the DNA breakage and repair needed for recombination. As “pioneer factors” in the process, both proteins are needed for successful meiosis and fertility.
A review in the journal Cell Stem Cells by two JAX scientists reports on the latest efforts to isolate and culture the elusive populations of stem cells that most closely resemble very early (two-cell stage) totipotent cells.