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Recombination Mechanisms
and the Maintenance of Genome Stability

   15th - 19th May | 2006 | Seillac | France

About the Conference:

The aim of this conference is to discuss all aspects of recombination in prokaryotes and eukaryotes. The emphasis will be on :

The 3-D structure of a Holliday junction

Robin Holliday first proposed this four-way junction, or crossover, that links recombining chromosomes. Physical and X-ray crystallographic studies have shown that the Holliday junction adopts an antiparallel helical structure in the presence of divalent metal ions. Resolution of the junction by specific endonucleases gives rise to recombinant chromosomes.

(Image courtesy of David Lilley)
Segregation of color and shape ascospore markers in Ascobolus

(A) 2 dark oval /2 dark round /2 white oval /2 white round ascospores : mendelian segregations.

(B) Aberrant 1 dark oval /3 dark round /3 white oval /1 white round ascospores. It reflects the formation of unrepaired symmetric heteroduplex incorporated in the Holliday's model.

(Image courtesy of Alain Nicolas)

The recombination-replication-chromosome segregation connection

Escherichia coli biochemistry and genetics have provided major insights into how recombination processes are linked to DNA replication and chromosome segregation. This understanding has been advanced by new techniques for visualising specific genes in living cells along with methods for analysing replication and recombination events at specific loci. The image shows the segregation pattern of two specific markers (red and green) in the E.coli replication termination region. Two sister chromosomes are stained with DAPI.

(Image courtesy of Xindan Wang, Christophe Possoz and David Sherratt).


Structure of RecBCD

The E. coli RecBCD protein is involved in the initiation of recombination. It is a bipolar DNA helicase that also functions as a nuclease to generate the substrate for the RecA recombinase.

(Image courtesy of Steve Kowalczykowski)