Exploring the Potential of the Microbiome as a Marker of the Geographic Origin of Fresh Seafood.

Geographic food fraud - misrepresenting the geographic origin of a food item, is very difficult to detect, and therefore this type of fraud tends to go undetected. This potentially negatively impacts the health of Canadians and economic success of our seafood industry. Surveillance studies have shown that up to a significant portion of commercially sold seafood items in Canada are mislabeled or otherwise misrepresented in some way.

Identification of three histone methyltransferases in Drosophila: dG9a is a suppressor of PEV and is required for gene silencing.

Organization of chromatin structure and regulation of gene transcription are contingent on histone tail modifications. Regions of the genome packaged with nucleosomes that contain methyl histone H3 at lysine 9 (Me K9H3) strongly correlate with regions that are silenced for transcription. To date Su(var)3-9 is the only K9H3 specific enzyme characterized in Drosophila melanogaster.

Bonus, a Drosophila TIF1 homolog, is a chromatin-associated protein that acts as a modifier of position-effect variegation.

Bonus, a Drosophila TIF1 homolog, is a nuclear receptor cofactor required for viability, molting, and numerous morphological events. Here we establish a role for Bonus in the modulation of chromatin structure. We show that weak loss-of-function alleles of bonus have a more deleterious effect on males than on females.

A role for the Drosophila SU(VAR)3-9 protein in chromatin organization at the histone gene cluster and in suppression of position-effect variegation.

Mutations in the gene for Su(var)3-9 are dominant suppressors of position-effect variegation (PEV). We show that SU(VAR)3-9 is a chromatin-associated protein and identify the large multicopy histone gene cluster (HIS-C) as one of its target loci. The organization of nucleosomes over the entire HIS-C region is altered in Su(var)3-9 mutants and there is a concomitant increase in expression of the histone genes.

HMG-D and histone H1 interplay during chromatin assembly and early embryogenesis.

HMG-D is an abundant chromosomal protein associated with condensed chromatin during the first nuclear cleavage cycles of the developing Drosophila embryo. We previously suggested that HMG-D might substitute for the linker histone H1 in the preblastoderm embryo and that this substitution might result in the characteristic less compacted chromatin. We have now studied the association of HMG-D with chromatin using a cell-free system for chromatin reconstitution derived from Drosophila embryos.