Mutation and selection explain why many eukaryotic centromeric DNA sequences are often A + T rich.

We have used chromosome engineering to replace native centromeric DNA with different test sequences at native centromeres in two different strains of the fission yeast Schizosaccharomyces pombe and have discovered that A + T rich DNA, whether synthetic or of bacterial origin, will function as a centromere in this species. Using genome size as a surrogate for the inverse of effective population size (Ne) we also show that the relative A + T content of centromeric DNA scales with Ne across 43 animal, fungal and yeast (Opisthokonta) species. This suggests that in most of these species the A + T content of the centromeric DNA is determined by a balance between selection and mutation.

Certain haplotypes of the 3'-UTR region of the HLA-G gene are linked to breast cancer.

: Human leukocyte antigen G belongs to the family of non-classical HLA class I genes, its expression considered an important immune escape mechanism of cancer cells. The polymorphisms in the 3'-untranslated region (UTR) region of HLA-G influence the magnitude of the protein by modulating HLA-G mRNA stability. We hypothesised links between any of eight (UTR) single nucleotide polymorphisms (SNPs) and their haplotype of the HLA-G gene with breast cancer.