Selected publications

• Brown Jill M and Buckle Veronica J (2009) FISH; Methods and Applications Humana Press. Methods in Molecular Biology.

• Brown Jill M, Green Joanne, das Neves Ricardo P, Wallace Helen AC, Smith Andrew JH, Hughes Jim, Gray Nicki, Taylor Steve, Wood William G, Higgs Douglas R, Iborra Francisco J, and Buckle Veronica J (2008) Association between active genes occurs at nuclear speckles and is modulated by chromatin environment. J Cell Biol, 182(6):1083-97.

• Hong Dengli, Gupta Rajeev, Ancliff Philip, Atzberger Ann, Brown John, Soneji Shamit, Green Joanne, Colman Sue, Piacibello Wanda, Buckle Veronica, Tsuzuki Shinobu, Greaves Mel, and Enver Tariq (2008) Initiating and cancer-propagating cells in TEL-AML1-associated childhood leukemia. Science, 319(5861):336-9.

• Iborra Francisco J and Buckle Veronica (2008) Wide confocal cytometry: a new approach to study proteomic and structural changes in the cell nucleus during the cell cycle. Histochem Cell Biol, 129(1):45-53.

• De Gobbi Marco, Viprakasit Vip, Hughes Jim R, Fisher Chris, Buckle Veronica J, Ayyub Helena, Gibbons Richard J, Vernimmen Douglas, Yoshinaga Yuko, de Jong Pieter, Cheng Jan-Fang, Rubin Edward M, Wood William G, Bowden Don, and Higgs Douglas R (2006) A regulatory SNP causes a human genetic disease by creating a new transcriptional promoter. Science, 312(5777):1215-7.

The nucleus is a highly ordered structure of chromatin and nuclear substructures, such as nucleoli, PML bodies, Cajal bodies and the splicing factor compartment of nuclear speckles. The genome itself is organised in a non-random fashion, both three-dimensionally and with regard to linear gene distribution, and it has been proposed that this organisation may play a role in the modulation of transcription. Transcription takes place in discrete foci or factories spread throughout the nucleus and it is likely that more than one gene occupies a factory when transcriptionally active. Genes on different chromosomes have been observed in close proximity or association in a percentage of nuclei. Our studies are directed at understanding the relevance of nuclear organisation to gene expression during erythropoiesis. Erythroid cells differentiate over the course of a few days from committed blast-forming cells, through the pronormoblast stage where they are highly proliferative and begin to produce large quantities of haemoglobin, to a condensed pyknotic state when nuclei are finally extruded from the cells. During this process, erythroid-specific genes are switched on and transcribe heavily before they are shut down.

Changes in nuclear activity and organisation during erythroid differentiation

We are characterising the organisation of erythroid genes and the surrounding chromatin during differentiation and looking at how nuclear proteins are distributed and reorganised in relation to active sites of transcription and post-transcriptional processing. We see no evidence that co-transcribed erythroid genes associate at shared transcription foci. It seems that the aggregation of splicing factors into the large nuclear speckles may be bringing active genes, particularly those on decondensed stretches of chromatin, into closer proximity.

(left) Erythroblast nucleus showing positioning of alpha globin (red), beta globin (white), SLC4A1 (green) and ERAF (blue) genes. Erythroid genes associate much more frequently when active and the association occurs at nuclear speckles

(right) Erythroid-specific genes, alpha globin (green) and SLC4A1 (red), sit at common SC35-enriched nuclear speckles (blue) in erythroblast nuclei

We are particularly focussing on the organisation of chromatin around the alpha globin genes on chromosome 16 short arm, looking at what changes in decondensation and structure are necessary for transcription. This is the region associated with alpha-thalassaemia and mental retardation (ATR16) syndrome, where we suspect an underlying structural basis to the aetiology of the chromosomal abnormalities that lead to ATR16 syndrome.

Hybridisation of a 2Mb cosmid contig extending from the telomere of chromosome 16 short arm showing how decondensed this region can be within the nucleus