Tim Thomas-Project

Tim Thomas-Project


Super Content: 
Dr Tim Thomas and Dr Anne Voss standing in lab with notebook

The discovery of a ‘switch’ that modifies a gene known to be essential for normal heart development could explain variations in the severity of birth defects in children with DiGeorge syndrome.

Chromatin-mediated mechanisms and retinoic acid coordinately regulate body segment identity

We showed that embryos deficient in the histone acetyltransferase MOZ (Myst3/Kat6a) show histone H3 lysine 9 (H3K9) hypoacetylation, corresponding H3K9 hypermethylation, and reduced transcription at Hox gene loci.

Consistent with an observed caudal shift in Hox gene expression, segment identity is shifted anteriorly, such that MOZ-deficient models show a profound homeotic transformation of the axial skeleton and the nervous system. Intriguingly, histone acetylation defects are relatively specific to H3K9 at Hox loci, as neither Hox H3K14 acetylation nor bulk H3K9 acetylation levels throughout the genome are strongly affected; H4K16 acetylation actually increases in the absence of MOZ. H3K9 hypoacetylation, Hox gene repression, and the homeotic transformation caused by lack of MOZ are all reversed by treatment with retinoic acid.

In conclusion, MOZ regulates H3K9 acetylation at Hox gene loci and that retinoic acid can act independently of MOZ to establish specific Hox gene expression boundaries.

Project leaders: Anne Voss, Tim Thomas