U.S. Department of Health and Human Services

Genetics and Biochemistry Branch

Rafael Daniel Camerini-Otero, M.D., Ph.D., Chief


Genetics and Biochemistry Section

Rafael Daniel Camerini-Otero, M.D., Ph.D.

The Genetics and Biochemistry Section studies the biochemistry, molecular, and cell biology of meiotic (homologous) recombination in mice and humans. Our focus is on understanding the biology of genetic recombination and to devise new strategies to manipulate complex genomes in vitro and, in the future, in vivo. Specific projects include biophysical and structural studies of proteins, protein domains and DNA-protein complexes involved, gene rearrangements in eukaryotes and, most recently, mouse and human meiosis and evolutionary genomics. Current interests include the study of Spo11, the protein responsible for the hundreds of developmentally programmed breaks in meiosis, what determines where these breaks are made and where crossovers are located, how homologous chromosomes find each other and how meiosis has shaped the sex chromosomes.

Genome Dynamics Section

Peggy Hsieh, Ph.D.

The Genome Dynamics Section focuses on a highly conserved DNA repair pathway, DNA mismatch repair. Mismatch repair targets base pair mismatches that arise through DNA replication errors, homologous recombination, and DNA damage. Inactivation of mismatch repair results in a large increase in the rate of spontaneous mutation and is associated with both sporadic and hereditary cancers. The Hsieh group utilizes biochemical, structural, and cell biological approaches to study mechanistic questions concerning mismatch excision repair and the cellular response to DNA damage.

Protein Biogenesis Section

Harris D. Bernstein, Ph.D.

The Protein Biogenesis Section studies protein secretion in both pathogenic and non-pathogenic bacteria. The Bernstein group continues to pursue a long-term interest in the universal Sec pathway and has recently been focusing on the mechanism by which the expression of secA, a key component of the Sec pathway, is controlled at the translational level. It has also been studying the secretion of virulence factors by the widespread but poorly understood autotransporter ("type V") pathway that is found in pathogenic Gram-negative bacteria.