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Fatakia, S. N.

Publications and source records attributed to Fatakia, S. N..

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Insights to the genetic etiology of a lifestyle-related disease with differential levels of severity using a hierarchy of common genetic variants

Genome evolution in disparate species is synopsized to highlight the role of common genetic variants during their adaptation, and an evolutionary perspective is provided to infer lifestyle-related disease progression in humans. Cardiovascular disease (CVD) is a multi-factorial disease, where maladaptation due to a sedentary lifestyle and faulty diet can influence its prognosis, but the genetic basis for its differential severity remains unknown. As a healthy diet and lifestyle may restrict its prognosis, we hypothesize that a hierarchy of common genetic variants may differentially modulate that severity in a subpopulation. We suggest that the loss-of-function paradigm due to a genetic variant may give rise to a broad spectrum of CVD severity in conjunction with other variants. Here, we have inferred that CAD severity may be a consequence of the plasticity of common variants exclusive among patients with disparate disease severity. Most importantly, we have used a small and outbred subpopulation to demonstrate that common genetic variants can be exploited to trace this unique facet of CAD etiology. Moreover, we corroborate our hypothesis by reporting that a hierarchical plasticity of the LDLR gene, which has been implicated in a differential response to lipid metabolism, is associated with differential CVD severity.\n\nCan we gain insight to the genetic etiology of diseases using a limited number of genomes (few hundred)? Can small data sets lend insights that large data sets may subsequently confirm? Here, I show how common genetic variants, which were identified only from hundreds of individuals, may be used to gain unique insights regarding the disease etiology of a common lifestyle-related disease.

evolutionary biology

Genome-level parameters describe the pan-nuclear fractal nature of eukaryotic interphase chromosomal arrangement

Long-range inter-chromosomal interactions in the interphase nucleus subsume critical genome-level regulatory functions such as transcription and gene expression. To decipher the physical basis of diverse pan-nuclear patterns of chromosomal arrangement that facilitates these processes, we investigate the scaling effects within disparate genomes and compared their total number of genes with chromosome size. First, we derived the pan-nuclear average fractal dimension of inter-chromosomal arrangement in interphase nuclei of different species and corroborated our predictions with independently reported results. Then, we described the different patterns across disparate unicellular and multicellular eukaryotes. We report that, unicellular lower eukaryotes have inter-chromosomal fractal dimension = 1 at the pan-nuclear scales, which is analogous to the multi-polymer crumpled globule model. Multi-fractal dimensions, corresponding to different inter-chromosomal arrangements emerged from multicellular eukaryotes, such that closely related species have relatively similar patterns. Using this theoretical approach, we could distinguish fractal patterns from human acrocentric versus metacentric chromosomes, implying that the multi-fractal nature of inter-chromosomal geometry facilitates viable large-scale chromosomal aberrations, such as Robertsonian translocations. We report that the nature of such an average multi-fractal dimension for nocturnal mammals is very different in diurnal mammals, which suggests a greatly enhanced plasticity in arrangement across different cell types, for example retinal versus dermal fibroblasts. Altogether, our results substantiate that genome-level constraints have also co-evolved with the average pan-nuclear fractal dimension of inter-chromosomal folding during eukaryotic evolution.

evolutionary biology