Biology subjects

Kwon, H. W.

Publications and source records attributed to Kwon, H. W..

4 recordsLinked to original sources

bioRxiv2023

Different Diets Modulate the Gut Microbiome Compositions and Promote the Health of Apis mellifera.

Honey bee (Apis mellifera) health is crucial for honey bee products, and effective pollination and is closely associated with gut bacteria. Various factors such as reduced habitat, temperature, disease, and diet affect the health of honey bees, by disturbing the homeostasis of the gut microbiota. In this study, high-throughput 16S rRNA gene sequencing was used to analyze the gut microbiota of Apis mellifera subjected to seven different diets. The identified microbiota in the Apis mellifera gut from all the diets consisted of Lactobacillus (62%), followed by Rhizobiaceae (21%), Snodgrassella (4%), and Erwiniaceae (4%) among other 33 genera. Based on diet types, Lactobacillus a lactic acid bacteria (LAB), dominates the microbiota with the highest relative abundance in AIGT+SAC (91%), AIGT+Soytide (88%), and AIGT+Apple juice (69%) diet groups. Bifidobacterium and Commensalibacter appeared as the second most abundant genera in AIGT+SAC and AIGT+Soytide diet groups, respectively. These bacteria are important markers for honey bee health. Considering the importance of these diets in shaping their host microbiome into a healthy status. Individual honey bee health (IHH) was observed to validate the quality and correlation between the microbiota and honey bee health. The results were consistent, indicating that Apis mellifera fed on AIGT+Soytide and AIGT+SAC diet showed the highest health expression level of vitellogenin. The group with 60%Syrup possessing Rhizobiaceae as the dominant taxa showed poor health status. This finding paved the way for establishing a link between gut microbiota and IHH under different diets.

genomics↗

bioRxiv2023

Identification of Essential Temperature-Stressed Genes From Apis mellifera Hypopharyngeal Glands Transcriptomes Under Variable Temperatures

Temperature is one of the essential abiotic factors required for honey bee survival and pollination. It affects honey bee physiology, behavior, and expression of related genes. Also, considered one of the major factors contributing to colony collapse disease (CCD). In this research, RNA-seq analysis was performed using hypopharyngeal glands (HGs) tissue at low (18 {degrees}C), high (25 {degrees}C), and regular (22 {degrees}C) temperatures. Differentially expressed genes (DEGs) were identified after comparing the three groups with one another based on temperature differences using DESeq analysis. 5196 common DEGs (cDEGs) were identified among the groups. They are highly enriched in RNA processing and RNA metabolism process while the KEGG pathway enrichment analysis showed that the cDEGs are enriched in longevity regulating pathway, MAPK signaling pathway-fly, and Glycerophospholipid metabolism. Further, 360 temperature-stressed genes identified are highly enriched in translation, oxidative activity, and ribonucleoprotein complex. The enriched KEGG pathway includes ribosome, oxidative phosphorylation, fatty acid metabolism, and citrate cycle (TCA cycle). All the top ten (10) hub genes among the 360 temperature-stressed genes are found up-regulated. In addition, heat-shock protein 90 (HSP90) known as the stressed response gene, and Gr10, the amino acid response gene were up-regulated and down-regulated respectively in the temperature-stressed group. Low expression of Gr10 under temperature-stress can affect nursing behavior and bee development. Ultimately, these findings will help in identifying honeybee-temperature survival mechanisms under varying temperature effects.

genomics↗

bioRxiv2022

Extensive mosaicism by somatic L1 retrotransposition in normal human cells

Over the course of an individuals lifetime, genomic alterations accumulate in somatic cells. However, the mutational landscape by retrotranspositions of long interspersed nuclear element-1 (L1), a widespread mobile element in the human genome, is poorly understood in normal cells. Here, we explored the whole-genome sequences of 892 single-cell clones established from various tissues collected from 28 individuals. Remarkably, 88% of colorectal epithelial cells acquired somatic L1 retrotranspositions (soL1Rs), carrying [~]3 events per cell on average with substantial intra- and inter-individual variances, which was accelerated at least 10-fold during tumourigenesis. Breakpoints of soL1Rs suggested that a few variant mechanisms can be involved in the L1 retrotransposition processes. Fingerprinting of donor L1s using source-specific unique sequences revealed 34 hot L1s, 44% of which were newly discovered in this study, and many ultra-rare hot L1s in the human population showed higher retrotransposition potential in somatic lineages than common sources. Multi-dimensional analysis of soL1Rs with early embryonic developmental relationships, genome-wide methylation, and gene expression profiles of the clones demonstrated that (1) soL1Rs occur from early embryogenesis at a substantial rate, (2) epigenetic activation of hot L1s is stochastically acquired during the wave of early global epigenomic reprogramming, rather than by the sporadic loss-of-methylation at the late stage, and (3) most L1 transcripts in the cytoplasm do not generate soL1Rs in somatic lineages. In summary, this study provides insights into the retrotransposition dynamics of L1s in the human genome and the resultant somatic mosaicism in normal human cells.

genomics↗

bioRxiv2021

Mutational impact and signature of ionizing radiation

Whole-genome sequencing (WGS) of human tumors and normal cells exposed to various carcinogens has revealed distinct mutational patterns that provide deep insights into the DNA damage and repair processes. Although ionizing radiation (IR) is conventionally known as a strong carcinogen, its genome-wide mutational impacts have not been comprehensively investigated at the single-nucleotide level. Here, we explored the mutational landscape of normal single-cells after exposure to the various levels of IR. On average, 1 Gy of IR exposure generated [~]16 mutational events with a spectrum consisting of predominantly small nucleotide deletions and a few characteristic structural variations. In [~]30% of the post-irradiated cells, complex genomic rearrangements, such as chromoplexy, chromothripsis, and breakage-fusion-bridge cycles, were resulted, indicating the stochastic and chaotic nature of DNA repair in the presence of the massive number of concurrent DNA double-strand breaks. These mutational signatures were confirmed in the genomes of 22 IR-induced secondary malignancies. With high-resolution genomic snapshots of irradiated cells, our findings provide deep insights into how IR-induced DNA damage and subsequent repair processes operate in mammalian cells.

genomics↗