Biology subjects

Kaduskar, B.

Publications and source records attributed to Kaduskar, B..

4 recordsLinked to original sources

bioRxiv2022

Conserved neuropeptidergic regulation of intestinal integrity in invertebrate models of aging

Age-related decline in intestinal barrier function impacts survival across species, but the underlying cell intrinsic and extrinsic factors remain unclear. Here, we demonstrate a role for neuropeptides in regulating aging-associated increases in intestinal leakiness. Adult-specific knockdown of insulin-like peptides daf-28 or ins-7 in C. elegans neurons or dilp3 in D. melanogaster neurons improves intestinal integrity and lifespan of these animals, respectively. Neuropeptide knockdowns activate intestinal DAF-16/FOXO transcription factor that likely increases expression of epithelial barrier components. Furthermore, age-associated changes in neuronal DAF-28 peptide secretion mirrors C. elegans reproductive span and overexpression of this peptide suppresses the improved intestinal health in long-lived germline-less animals. Collectively, we show that intestinal integrity is subject to neuronal regulation, and this neuropeptidergic axis may be modulated by the animals germline.

neuroscience↗

bioRxiv2021

Caspar, an adapter for VAP and TER94, delays the progression of disease by regulating glial inflammation in a Drosophila model of ALS8

Amyotrophic Lateral Sclerosis (ALS) is a fatal, late onset, progressive motor neurodegenerative disorder. We have been studying cellular and molecular mechanisms involved in ALS using a vesicle-associated membrane protein-associated protein B (VAPB/ALS8) Drosophila model, which mimics many systemic aspects of the human disease. Here, we show that the ER resident VAPB interacts with Caspar, an ortholog of human fas associated factor 1 (FAF1). Caspar, in turn, interacts with transitional endoplasmic reticulum ATPase (TER94), a fly ortholog of ALS14 (VCP/p97, Valosin-containing protein), via its UBX domain and poly-ubiqutinated proteins with its UBA domain. Caspar overexpression in the glia extends lifespan and also slows the progression of motor dysfunction in the ALS8 model, a phenomenon that we ascribe to its ability to restrain age-dependant inflammation, modulated by Relish/NF{kappa}B signalling. We hypothesize that Caspar is a key molecule in the pathogenesis of ALS. Caspar connects the plasma membrane (PM) localized immune signalosome to the ER based VAPB degradative machinery, presumably at PM:ER contact sites. The Caspar:TER94:VAPB complex appears to be a strong candidate for regulating both protein homeostasis and NF{kappa}B signalling. These, in turn, regulate glial inflammation and determine progression of disease. Our study projects human FAF1 as an important protein target to alleviate the progression of motor neuron disease.

genetics↗

bioRxiv2020

Hidden features of the malaria vectormosquito, Anopheles stephensi ,revealed by a high-quality referencegenome

BackgroundThe mosquito Anopheles stephensi is a vector of urban malaria in Asia that recently invaded Africa. Studying the genetic basis of vectorial capacity and engineering genetic interventions are both impeded by limitations of a vectors genome assembly. The existing assemblies of An. stephensi are draft-quality and contain thousands of sequence gaps, potentially missing genetic elements important for its biology and evolution. ResultsTo access previously intractable genomic regions, we generated a reference-grade genome assembly and full transcript annotations that achieve a new standard for reference genomes of disease vectors. Here, we report novel species-specific transposable element families and insertions in functional genetic elements, demonstrating the widespread role of TEs in genome evolution and phenotypic variation. We discovered 29 previously hidden members of insecticide resistance genes, uncovering new candidate genetic elements for the widespread insecticide resistance observed in An. stephensi. We identified 2.4 Mb of the Y-chromosome and seven new male-linked gene candidates, representing the most extensive coverage of the Y-chromosome in any mosquito. By tracking full length mRNA for >15 days following blood feeding, we discover distinct roles of previously uncharacterized genes in blood metabolism and female reproduction. The Y-linked heterochromatin landscape reveals extensive accumulation of long-terminal repeat retrotransposons throughout the evolution and degeneration of this chromosome. Finally, we identify a novel Y-linked putative transcription factor that is expressed constitutively through male development and adulthood, suggesting an important role throughout male development. ConclusionCollectively, these results and resources underscore the significance of previously hidden genomic elements in the biology of malaria mosquitoes and will accelerate development of genetic control strategies of malaria transmission.

genomics↗

bioRxiv2018

Drosophila DNA/RNA methyltransferase contributes to robust host defense in ageing animals by regulating sphingolipid metabolism

Drosophila methyltransferase (Mt2) has been implicated in methylation of both DNA and tRNA. In this study, we demonstrate that loss of Mt2 activity leads to an age dependent decline of immune function in the adult fly. A newly eclosed adult has mild immune defects that exacerbate in a fifteen-day old Mt2-/- fly. The age dependent effects appear to be systemic, including disturbances in lipid metabolism, changes in cell shape of hemocytes and significant fold changes in levels of transcripts related to host defense. Lipid imbalance, as measured by quantitative lipidomics, correlates with immune dysfunction with high levels of immunomodulatory lipids, sphingosine-1phosphate (S1P) and ceramides, along with low levels of storage lipids. Activity assays on fly lysates confirm the age dependent increase in S1P and concomitant reduction of S1P lyase activity. We hypothesize that Mt2 functions to regulate genetic loci such as S1P lyase and this regulation is essential for robust host defense as the animal ages. Our study uncovers novel links between age dependent Mt2 function, innate immune response and lipid homeostasis.

immunology↗