Biology subjects

Kabiraj, D.

Publications and source records attributed to Kabiraj, D..

3 recordsLinked to original sources

bioRxiv2025

Complex HPV-human DNA structures revealed by large-scale DNA analyses in an HPV-cancer derived cell line

Most human papillomavirus (HPV)-associated cancers harbor viral DNA integrated into the human genome as extrachromosomal circles, intrachromosomal segments, or both. Distinguishing intrachromosomal from identical-sequence extrachromosomal DNA (ecDNA) by sequencing alone is challenging, and the architecture of large-scale HPV-human DNA structures remains incompletely understood. To address this, we applied complementary genomic tools, spanning single-nucleotide to megabase resolution, to the HPV16-positive oropharyngeal cancer-cell line UM-SCC-47. These revealed that an initial integration event formed a 23 kb extrachromosomal heterocatemer circle comprising 7.5 kb of HPV16 DNA and 16 kb of the human TP63 gene. Subsequent genomic rearrangements generated heterocatemer tandem arrays extending to 0.6 megabases, plus additional large-scale rearrangements involving the HPV-TP63 structures, as revealed by long-read DNA sequencing and optical genome mapping. Fluorescent in situ Hybridization (FISH) showed that the heterocatemers were intrachromosomally localized at chromosome 3 at the TP63 locus in 100% of the cells. Long-read RNA sequencing further showed that these intrachromosomal templates produced spliced, polyadenylated transcripts. A subset of cells also harbored HPV16 ecDNA derived from the intrachromosomal HPV-TP63 DNAs. These findings define previously unrecognized higher-order architecture of integrated HPV DNA and highlight the power of FISH for distinguishing intrachromosomal from extrachromosomal DNA structures. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=76 SRC="FIGDIR/small/680684v1_ufig1.gif" ALT="Figure 1"> View larger version (20K): org.highwire.dtl.DTLVardef@f3d584org.highwire.dtl.DTLVardef@470811org.highwire.dtl.DTLVardef@162c88corg.highwire.dtl.DTLVardef@5c80dd_HPS_FORMAT_FIGEXP M_FIG C_FIG

genomics↗

bioRxiv2017

Comparative insights to the transportome of Nosema: a genus of parasitic microsporidians

Nosema, a genus of parasitic microsporidia, causes pebrine disease in arthropods, including economically important silkworms and honeybees. Nosema have gene-poor genomes shaped by loss of the metabolic pathways, as a consequence of continued dependence on host-derived substrates. As an act of counterbalance, they have developed an array of transporter proteins that allow stealing from their hosts. Here, we have identified the core set of twelve transporter families present in Nosema genus, viz. N. apis, N. bombycis, N. ceranae and N. antheraea through in silico pipeline. Transportomes of N. apis, N. bombycis, N. ceranae and N. antheraea have a dominant share of secondary carriers and primary active transporters. The comparatively rich and diverse transportome of N. bombycis indicates the role of transporters in its remarkable capability of host adaptation. The core set of transporter families of Nosema includes ones that have a likely role in osmo-regulation, intra- and extra-cellular pH regulation, energy compensation and self-defence mechanism. This study has also revealed a set of ten species-specific transporter families within the genus. To our knowledge, this is the first ever intra-genus study on microsporidian transporters. Both these datasets constitutes a valuable resource that can aid in development of inhibitor-based Nosema management strategies.

bioinformatics↗

bioRxiv2017

Complete mitochondrial genome of golden silk producer Antheraea assamensis and its comparative analysis with other lepidopteran insects

Muga (Antheraea assamensis) is an economically important silkmoth endemic to North-eastern part of India and is the producer of the strongest known commercial silk. However, there is a scarcity of -omics data for understanding the organism at a molecular level. Our present study decodes the complete mitochondrial genome (mitogenome) of A. assamensis and presents comparative analysis with other lepidopterans. Mitogenome is a 15,272 bp long AT rich (~80.2%) molecule containing 37 genes (13 PCGs, 22 tRNAs, 2 rRNAs) and a 328 bp long control region. The overall mitogenome arrangement was similar to the other lepidopterans. Two PCGs cox1 and cox2 were found to have CGA and GTG as start codons respectively like some lepidopterans. Typical clover-leaf shaped secondary structures of tRNAs were found with a few exceptions such as unstable DHU and T{Psi}C loop in tRNASer1 and tRNATyr; significant number of mismatches (35) spread over 19 tRNAs. The control region contained a six bp deletion atypical of other Antheraea species. Phylogenetic position was consistent with the traditional taxonomic classification of Saturniidae. The complete annotated mitogenome is available in GenBank (Accession No. KU379695). To the best of our knowledge, this is the first report on complete mitogenome of A. assamensis.

evolutionary biology↗