Biology subjects

Liao, H.

Publications and source records attributed to Liao, H..

3 recordsLinked to original sources

bioRxiv2018

Large-scale neuroimaging and genetic study reveals genetic architecture of brain white matter microstructure

Microstructural changes of white matter (WM) tracts are known to be associated with various neuropsychiatric disorders/diseases. Heritability of structural changes of WM tracts has been examined using diffusion tensor imaging (DTI) in family-based studies for different age groups. The availability of genetic and DTI data from recent large population-based studies offers opportunity to further improve our understanding of genetic contributions. Here, we analyzed the genetic architecture of WM tracts using DTI and single-nucleotide polymorphism (SNP) data of unrelated individuals in the UK Biobank (n [~] 8000). The DTI parameters were generated using the ENIGMA-DTI pipeline. We found that DTI parameters are substantially heritable on most WM tracts. We observed a highly polygenic or omnigenic architecture of genetic influence across the genome as well as the enrichment of SNPs in active chromatin regions. Our bivariate analyses showed strong genetic correlations for several pairs of WM tracts as well as pairs of DTI parameters. We performed voxel-based analysis to illustrate the pattern of genetic effects on selected parts of the tract-based spatial statistics skeleton. Comparing the estimates from the UK Biobank to those from small population-based studies, we illustrated that sufficiently large sample size is essential for genetic architecture discovery in imaging genetics. We confirmed this finding with a simulation study.

genetics↗

bioRxiv2017

Heritability of regional brain volumes in large-scale neuroimaging and genetic studies

Brain genetics is an active research area. The degree to which genetic variants impact variations in brain structure and function remains largely unknown. We examined the heritability of regional brain volumes (p ~ 100) captured by single-nucleotide polymorphisms (SNPs) in UK Biobank (n ~ 9000). We found that regional brain volumes are highly heritable in this study population. We observed omni-genic impact across the genome as well as enrichment of SNPs in active chromatin regions. Principal components derived from regional volume data are also highly heritable, but the amount of variance in brain volume explained by the component did not seem to be related to its heritability. Heritability estimates vary substantially across large-scale functional networks and brain regions. The variation in heritability across regions was not related to measurement reliability. Heritability estimates exhibit a symmetric pattern across left and right hemispheres and are consistent in females and males. Our main findings in UK Biobank are consistent with those in Alzheimers Disease Neuroimaging Initiative (n ~ 1100), Philadelphia Neurodevelopmental Cohort (n ~ 600), and Pediatric Imaging, Neurocognition, and Genetics (n ~ 500) datasets, with more stable estimates in UK Biobank.

genetics↗

bioRxiv2017

Transcriptome analysis of the quantitative distribution of the Cyrtotrachelus buqueti population in two cities in China

Background: Cyrtotrachelus buqueti is a forest pest that severely damages bamboo shoots. Reducing the population of this insect involves complex mechanisms and is dependent on diverse gene expression influenced by environmental factors.\n\nMethods: In this study, samples from two regions of China, Muchuan in Sichuan Province and Chishui in Guizhou Province, were investigated through RNA-seq to explore the causes and molecular mechanisms underlying the population reduction of this species. Environmental factors, such as temperature, heavy metal content, and pH, may affect the reduced population of C. buqueti in Chishui.\n\nResults: Approximately 44 million high-quality reads were generated, and 94.2% of the data were mapped to the transcriptome. A total of 15,641 out of the 29,406 identified genes were predicted. Moreover, 348 genes were differentially expressed between the two groups of imagoes and included 77 upregulated and 271 downregulated UniGenes. The functional analysis showed that these genes were significantly enriched in ribosome and metabolic pathway categories. The candidate genes, which contributed to C. Buqueti reduction, included 41 genes involved in the ribosome constitution category, five genes in the one-carbon pool pathway by folate category, and five heat shock protein genes.\n\nConclusions: Downregulation of these candidate genes seems to have impaired metabolic processes, such as protein, DNA, RNA, and purine synthesis, as well as carbon and folate metabolism, and finally resulted in the observed reduced population of C. buqueti. Furthermore, temperature, heavy metal content, and pH might influence the population by altering the expressions of genes involved in these metabolic processes.

genomics↗