Association of adipogenic genes with SC-35 domains during porcine adipogenesis.
Spatial organization of the genome within interphase nuclei is non-random. It has been shown that not only whole chromosomes but also individual genes occupy specific nuclear locations and these locations can be changed during different processes like differentiation or disease. Using a porcine in vitro adipogenesis stem cell differentiation system as a model to study nuclear organization, it was demonstrated that nuclear position of selected genes involved in porcine adipogenesis was altered with the up-regulation of gene expression, correlating with these genes becoming more internally located within nuclei, without whole territory relocation. Here, we investigated whether the gene relocation observed during porcine adipogenesis is related to spatial co-association with SC-35 domains. These domains are nuclear speckles enriched in numerous splicing and RNA metabolic factors. Using a DNA immuno-FISH approach we investigated the localisation of three adipogenic genes (PPARG, SREBF1, and FABP4) with SC-35 domains in porcine mesenchymal stem cells and after they were differentiated into adipocytes. We found that the location of these genes relative to SC-35 domains was non-random and correlated with the up-regulation of gene expression. In addition, we observed more frequent clustering of the studied genes located on different chromosomes around the same nuclear speckle in differentiated adipocytes than in mesenchymal stem cells. However, the choice of the domain was more random. This study adds to the evidence that SC-35 domains are hubs of gene activity and gene-domain association may be considered as a common mechanism to enhance gene expression.
Department of Genetics and Animal Breeding, Poznan University of Life Sciences, Wolynska 33, 60-637 Poznan, Poland, izabel@jay.au.poznan.pl
Izabela
I
Szczerbal
Joanna M
JM
Bridger
D017667:Adipocytes / Q000166:cytology; D050156:Adipogenesis / Q000235:genetics*; D000818:Animals; D002467:Cell Nucleus / Q000235:genetics* / Q000378:metabolism*; D050556:Fatty Acid-Binding Proteins / Q000235:genetics; D017404:In Situ Hybridization, Fluorescence; D007399:Interphase; D059630:Mesenchymal Stem Cells / Q000166:cytology; D047495:PPAR gamma / Q000235:genetics; D017434:Protein Structure, Tertiary; D012261:Ribonucleoproteins / Q000235:genetics* / Q000378:metabolism*; D051780:Sterol Regulatory Element Binding Protein 1 / Q000235:genetics; D013552:Swine
D050556:Fatty Acid-Binding Proteins; D047495:PPAR gamma; D012261:Ribonucleoproteins; D051780:Sterol Regulatory Element Binding Protein 1