Abhishek A0bhishek

Dr. Abhishek A0bhishek

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Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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31 January 2018 in Scientific Reports
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SSSean Schoville
Sean Schoville
YCYolanda H. Chen
Yolanda H. Chen
MAMartin N. Andersson
Martin N. Andersson
JBJoshua B. Benoit
Joshua B. Benoit
ABAnita Bhandari
Anita Bhandari
SRStephen Richards
Stephen Richards
The Colorado potato beetle is one of the most challenging agricultural pests to manage. It has shown a spectacular ability to adapt to a variety of solanaceaeous plants and variable climates during its global invasion, and, notably, to rapidly evolve insecticide resistance. To examine evidence of rapid evolutionary change, and to understand the genetic basis of herbivory and insecticide resistance, we tested for structural and functional genomic changes relative to other arthropod species using genome sequencing, transcriptomics, and community annotation. Two factors that might facilitate rapid evolutionary change include transposable elements, which comprise at least 17% of the genome and are rapidly evolving compared to other Coleoptera, and high levels of nucleotide diversity in rapidly growing pest populations. Adaptations to plant feeding are evident in gene expansions and differential expression of digestive enzymes in gut tissues, as well as expansions of gustatory receptors for bitter tasting. Surprisingly, the suite of genes involved in insecticide resistance is similar to other beetles. Finally, duplications in the RNAi pathway might explain whyLeptinotarsa decemlineatahas high sensitivity to dsRNA. TheL.decemlineatagenome provides opportunities to investigate a broad range of phenotypes and to develop sustainable methods to control this widely successful pest.

31 May 2024 in Medcomm
Verified
Journal Article
Open access
TDTikam Chand Dakal
Tikam Chand Dakal
BDBhanupriya Dhabhai
Bhanupriya Dhabhai
APAnuja Pant
Anuja Pant
KMKareena Moar
Kareena Moar
KCKanika Chaudhary
Kanika Chaudhary
Amit SharmaAmit Sharma
Amit Sharma
Cancer, being the most formidable ailment, has had a profound impact on the human health. The disease is primarily associated with genetic mutations that impact oncogenes and tumor suppressor genes (TSGs). Recently, growing evidence have shown that X‐linked TSGs have specific role in cancer progression and metastasis as well. Interestingly, our genome harbors around substantial portion of genes that function as tumor suppressors, and the X chromosome alone harbors a considerable number of TSGs. The scenario becomes even more compelling as X‐linked TSGs are adaptive to key epigenetic processes such as X chromosome inactivation. Therefore, delineating the new paradigm related to X‐linked TSGs, for instance, their crosstalk with autosome and involvement in cancer initiation, progression, and metastasis becomes utmost importance. Considering this, herein, we present a comprehensive discussion of X‐linked TSG dysregulation in various cancers as a consequence of genetic variations and epigenetic alterations. In addition, the dynamic role of X‐linked TSGs in sex chromosome–autosome crosstalk in cancer genome remodeling is being explored thoroughly. Besides, the functional roles of ncRNAs, role of X‐linked TSG in immunomodulation and in gender‐based cancer disparities has also been highlighted. Overall, the focal idea of the present article is to recapitulate the findings on X‐linked TSG regulation in the cancer landscape and to redefine their role toward improving cancer treatment strategies.

18 June 2013 in BMC Genomics
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MVMichele Vidotto
Michele Vidotto
AGAlessandro Grapputo
Alessandro Grapputo
EBElisa Boscari
Elisa Boscari
FBFederica Barbisan
Federica Barbisan
ACAlessandro Coppe
Alessandro Coppe
Leonardo CongiuLeonardo Congiu
Leonardo Congiu
Sturgeons are a group of Condrostean fish with very high evolutionary, economical and conservation interest. The eggs of these living fossils represent one of the most high prized foods of animal origin. The intense fishing pressure on wild stocks to harvest caviar has caused in the last decades a dramatic decline of their distribution and abundance leading the International Union for Conservation of Nature to list them as the more endangered group of species. As a direct consequence, world-wide efforts have been made to develop sturgeon aquaculture programmes for caviar production. In this context, the characterization of the genes involved in sex determination could provide relevant information for the selective farming of the more profitable females. The 454 sequencing of two cDNA libraries from the gonads and brain of one male and one female full-sib A. naccarii, yielded 182,066 and 167,776 reads respectively, which, after strict quality control, were iterative assembled into more than 55,000 high quality ESTs. The average per-base coverage reached by assembling the two libraries was 4X. The multi-step annotation process resulted in 16% successfully annotated sequences with GO terms. We screened the transcriptome for 32 sex-related genes and highlighted 7 genes that are potentially specifically expressed, 5 in male and 2 in females, at the first life stage at which sex is histologically identifiable. In addition we identified 21,791 putative EST-linked SNPs and 5,295 SSRs. This study represents the first large massive release of sturgeon transcriptome information that we organized into the public database AnaccariiBase, which is freely available at http://compgen.bio.unipd.it/anaccariibase/ . This transcriptomic data represents an important source of information for further studies on sturgeon species. The hundreds of putative EST-linked molecular makers discovered in this study will be invaluable for sturgeon reintroduction and breeding programs.

19 September 2013 in PLOS Genetics
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STStefanie Traeger
Stefanie Traeger
FAFlorian Altegoer
Florian Altegoer
MFMichael Freitag
Michael Freitag
TGToni Gabaldon
Toni Gabaldon
FKFrank Kempken
Frank Kempken
MNMinou Nowrousian
Minou Nowrousian
Fungi are a large group of eukaryotes found in nearly all ecosystems. More than 250 fungal genomes have already been sequenced, greatly improving our understanding of fungal evolution, physiology, and development. However, for the Pezizomycetes, an early-diverging lineage of filamentous ascomycetes, there is so far only one genome available, namely that of the black truffle, Tuber melanosporum, a mycorrhizal species with unusual subterranean fruiting bodies. To help close the sequence gap among basal filamentous ascomycetes, and to allow conclusions about the evolution of fungal development, we sequenced the genome and assayed transcriptomes during development of Pyronema confluens, a saprobic Pezizomycete with a typical apothecium as fruiting body. With a size of 50 Mb and ∼13,400 protein-coding genes, the genome is more characteristic of higher filamentous ascomycetes than the large, repeat-rich truffle genome; however, some typical features are different in the P. confluens lineage, e.g. the genomic environment of the mating type genes that is conserved in higher filamentous ascomycetes, but only partly conserved in P. confluens. On the other hand, P. confluens has a full complement of fungal photoreceptors, and expression studies indicate that light perception might be similar to distantly related ascomycetes and, thus, represent a basic feature of filamentous ascomycetes. Analysis of spliced RNA-seq sequence reads allowed the detection of natural antisense transcripts for 281 genes. The P. confluens genome contains an unusually high number of predicted orphan genes, many of which are upregulated during sexual development, consistent with the idea of rapid evolution of sex-associated genes. Comparative transcriptomics identified the transcription factor gene pro44 that is upregulated during development in P. confluens and the Sordariomycete Sordaria macrospora. The P. confluens pro44 gene (PCON_06721) was used to complement the S. macrospora pro44 deletion mutant, showing functional conservation of this developmental regulator. Fungi are a morphologically and physiologically diverse group of organisms with huge impacts on nearly all ecosystems. In recent years, genomes of many fungal species have been sequenced and have greatly improved our understanding of fungal biology. Ascomycetes are the largest fungal group with the highest number of sequenced genomes; however, for the Pezizales, an early-diverging lineage of filamentous ascomycetes, only one genome has been sequence to date, namely that of the black truffle. While truffles are among the most valuable edible fungi, they have a specialized life style as plant symbionts producing belowground fruiting bodies; thus it is difficult to draw conclusions about basal ascomycetes from one truffle genome alone. Therefore, we have sequenced the genome and several transcriptomes of the basal ascomycete Pyronema confluens, which has a saprobic life style typical of many ascomycetes. Comparisons with other fungal genomes showed that P. confluens has two conserved mating type genes, but that the genomic environment of the mating type genes is different from that of higher ascomycetes. We also found that a high number of orphan genes, i.e. genes without homologs in other fungi, are upregulated during sexual development. This is consistent with rapid evolution of sex-associated genes.

23 January 2014 in PLOS ONE
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AAAbhishek A0bhishek
Abhishek A0bhishek
Leonardo CongiuLeonardo Congiu
Leonardo Congiu
LLLeena Lindström
Leena Lindström
SPSaija Piiroinen
Saija Piiroinen
MVMichele Vidotto
Michele Vidotto
AGAlessandro Grapputo
Alessandro Grapputo
The Colorado potato beetle (Leptinotarsa decemlineata) is a major pest and a serious threat to potato cultivation throughout the northern hemisphere. Despite its high importance for invasion biology, phenology and pest management, little is known about L. decemlineata from a genomic perspective. We subjected European L. decemlineata adult and larval transcriptome samples to 454-FLX massively-parallel DNA sequencing to characterize a basal set of genes from this species. We created a combined assembly of the adult and larval datasets including the publicly available midgut larval Roche 454 reads and provided basic annotation. We were particularly interested in diapause-specific genes and genes involved in pesticide and Bacillus thuringiensis (Bt) resistance. Using 454-FLX pyrosequencing, we obtained a total of 898,048 reads which, together with the publicly available 804,056 midgut larval reads, were assembled into 121,912 contigs. We established a repository of genes of interest, with 101 out of the 108 diapause-specific genes described in Drosophila montana; and 621 contigs involved in insecticide resistance, including 221 CYP450, 45 GSTs, 13 catalases, 15 superoxide dismutases, 22 glutathione peroxidases, 194 esterases, 3 ADAM metalloproteases, 10 cadherins and 98 calmodulins. We found 460 putative miRNAs and we predicted a significant number of single nucleotide polymorphisms (29,205) and microsatellite loci (17,284). This report of the assembly and annotation of the transcriptome of L. decemlineata offers new insights into diapause-associated and insecticide-resistance-associated genes in this species and provides a foundation for comparative studies with other species of insects. The data will also open new avenues for researchers using L. decemlineata as a model species, and for pest management research. Our results provide the basis for performing future gene expression and functional analysis in L. decemlineata and improve our understanding of the biology of this invasive species at the molecular level.

21 September 2024 in Medcomm
Verified
Journal Article
Open access
TDTikam Chand Dakal
Tikam Chand Dakal
RBRavi Bhushan
Ravi Bhushan
CXCaiming Xu
Caiming Xu
BGBhana Ram Gadi
Bhana Ram Gadi
SCSwaranjit Singh Cameotra
Swaranjit Singh Cameotra
Amit SharmaAmit Sharma
Amit Sharma
Cancer stem cells (CSCs) are widely acknowledged as the drivers of tumor initiation, epithelial‐mesenchymal transition (EMT) progression, and metastasis. Originating from both hematologic and solid malignancies, CSCs exhibit quiescence, pluripotency, and self‐renewal akin to normal stem cells, thus orchestrating tumor heterogeneity and growth. Through a dynamic interplay with the tumor microenvironment (TME) and intricate signaling cascades, CSCs undergo transitions from differentiated cancer cells, culminating in therapy resistance and disease recurrence. This review undertakes an in‐depth analysis of the multifaceted mechanisms underlying cancer stemness and CSC‐mediated resistance to therapy. Intrinsic factors encompassing the TME, hypoxic conditions, and oxidative stress, alongside extrinsic processes such as drug efflux mechanisms, collectively contribute to therapeutic resistance. An exploration into key signaling pathways, including JAK/STAT, WNT, NOTCH, and HEDGEHOG, sheds light on their pivotal roles in sustaining CSCs phenotypes. Insights gleaned from preclinical and clinical studies hold promise in refining drug discovery efforts and optimizing therapeutic interventions, especially chimeric antigen receptor (CAR)‐T cell therapy, cytokine‐induced killer (CIK) cell therapy, natural killer (NK) cell‐mediated CSC‐targeting and others. Ultimately use of cell sorting and single cell sequencing approaches for elucidating the fundamental characteristics and resistance mechanisms inherent in CSCs will enhance our comprehension of CSC and intratumor heterogeneity, which ultimately would inform about tailored and personalized interventions.