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Biology subjects

Batrakou, D. G.

Publications and source records attributed to Batrakou, D. G..

2 recordsLinked to original sources

Genomic loci mispositioning in Tmem120a knockout mice yields latent lipodystrophy

Little is known about the proteins that direct the highly conserved patterns of spatial genome organisation in fat. Here we report that adipocyte-specific knockout of the gene encoding nuclear envelope protein Tmem120a disrupts fat genome organisation, thus causing a novel lipodystrophy syndrome. Tmem120a deficiency broadly suppresses lipid metabolism pathway gene expression and induces myogenic gene expression by repositioning genes, enhancers and miRNA-encoding loci between the nuclear periphery and interior. Tmem120a-/- mice, particularly females, exhibit a lipodystrophy syndrome similar to human familial partial lipodystrophy FPLD2, with profound insulin resistance and metabolic defects that manifests upon exposure to an obesogenic diet. Interestingly, similar genome organisation defects occurred in cells from FPLD2 patients that harbour nuclear envelope protein laminA mutations. Our data suggest TMEM120A may mediate/instigate novel categories of adipose tissue dysfunction across the adiposity spectrum and provide a new miRNA-based mechanism possibly driving the unexplained muscle hypertrophy in human lipodystrophy.

cell biology↗

Rapid high-resolution measurement of DNA replication timing by droplet digital PCR

Genomes are replicated in a reproducible temporal pattern. Current methods for assaying allele replication timing are time consuming and/or expensive. These include high-throughput sequencing which can be used to measure DNA copy number as a proxy for allele replication timing. Here, we use droplet digital PCR to study DNA replication timing at multiple loci in budding yeast and human cells. We establish that the method has temporal and spatial resolutions comparable to the high-throughput sequencing approaches, while being faster than alternative locus-specific methods. Furthermore, the approach is capable of allele discrimination. We apply this method to determine relative replication timing across timing transition zones in cultured human cells. Finally, multiple samples can be analysed in parallel, allowing us to rapidly screen kinetochore mutants for perturbation to centromere replication timing. Therefore, this approach is well suited to the study of locus-specific replication and the screening of cis- and trans-acting mutants to identify mechanisms that regulate local genome replication timing.

molecular biology↗