Remodeling chromatin remodeling.

For most genes in diploid organisms both alleles are transcribed in each cell. However, for a small class of genes only one of the alleles is preferentially transcribed in each cell, a phenomenon broadly known as monoallelic expression. Monoallelic expression is thought to be linked to a differential state of the chromatin structure for the two different alleles, which will lead to the specific allele expression or not. Our question is to understand how the two alleles can be differentially transcribed. Here we propose monoallelic expression to be a stochastic process and will present a stochastic differential model to account for the chromatin state and discuss its implications and limitations.

"Size Estimates of the alpha/beta TCR Repertoire of Naive Mouse Splenocytes."

Journal Club.

"The Germinal Center Reaction Memory or Plasma B cells: "Who" takes the decision?."

Not Supplied.

"A model for Homologus Recombination: speciation, sex and cancer."

A species may be defined as a population of organisms capable of sharing their gene pool through mating and genetic recombination. The inability to undergo genetic recombination with each other isolates related species independently of geographic isolation. The structural basis of the barrier to genetic recombination on the molecular level is the difference in their DNA sequences. I will present a mathematical relationship between recombination frequency and genomic sequence divergence (between recombining DNA strains). The implications of this relationship are then discussed according to speciation phenomena, sexual events and cancer.