The context-specific, complex issue of ‘vaccine hesitancy’ is explicated in terms of delay or ref... more The context-specific, complex issue of ‘vaccine hesitancy’ is explicated in terms of delay or refusal of vaccination despite the availability of vaccine services. Although eleven million beneficiaries were administered the COVID-19 vaccine in India from 16th January 2021 till 20th February 2021, however, proportionately a low turnout has been registered in various parts of the country, possibly attributable to hesitance/apprehension towards the current vaccination. In this backdrop, we report the response (collected between Feb 1, 2021 and Feb 15, 2021) of 358 voluntary respondents who participated in an online questionnaire-based pan-India survey, executed to assess their knowledge and acceptance towards the current COVID-19 vaccination program in its first phase. The survey questionnaire consisted of demographic characteristics of the respondents and queries pertaining to knowledge (7 items) and acceptance (3 items). The overall correct rate and the average knowledge score of the ...
Reactive oxygen species (ROS) generation within a cell is a natural process of specific subcellul... more Reactive oxygen species (ROS) generation within a cell is a natural process of specific subcellular components involved in redox reactions. Within a plant cell, chloroplasts are one of the major sources of ROS generation. Plastid‐generated ROS molecules include singlet oxygen (1O2), superoxide radical (O2–), hydroxyl radical (OH•) and hydrogen peroxide (H2O2), which are produced mainly during photochemical reactions of photosynthesis and chlorophyll biosynthetic process. Under normal growth and developmental, generated ROS molecules act as a secondary messenger controlling several metabolic reactions; however, perturbed environmental conditions lead to multi‐fold amplification of cellular ROS that eventually kill the target cell. To maintain homeostasis between production and scavenging of ROS, the cell has instituted several enzymatic and non‐enzymatic antioxidant machineries to maintain ROS at a physiological level. Among chloroplastic ROS molecules, excess generation of singlet o...
Miro (mitochondrial Rho GTPases), a mitochondrial outer membrane protein, facilitates mitochondri... more Miro (mitochondrial Rho GTPases), a mitochondrial outer membrane protein, facilitates mitochondrial axonal transport along the microtubules to facilitate neuronal function. It plays an important role in regulating mitochondrial dynamics (fusion and fission) and cellular energy generation. Thus, Miro might be associated with the key pathologies of several neurodegenerative diseases (NDs) including Alzheimer's disease (AD). In the present manuscript, we have demonstrated the possible genetic interaction between Miro and AD-related genes such as Tau, Aβ42 and Appl in Drosophila melanogaster. Ectopic expression of Tau, Aβ42 and Appl induced a rough eye phenotype, defects in phototaxis and climbing activity, and shortened lifespan in the flies. In our study, we have observed that overexpression of Miro improves the rough eye phenotype, behavioral activities (climbing and phototaxis) and ATP level in AD model flies. Further, the improvement examined in AD-related phenotypes was correl...
The use of transposons to create mutants has been the cornerstone ofDrosophilagenetics in the pas... more The use of transposons to create mutants has been the cornerstone ofDrosophilagenetics in the past few decades. Transpositions often create second-site mutations, devoid of transposon insertion and thereby affect subsequent phenotype analyses. In aP-element mutagenesis screen, a second site mutant was discovered on chromosome 3 wherein the homozygous mutant individuals show the classic hallmarks of mutations in tumor suppressor genes including brain tumour and lethality, hence the mutant line was initially named aslethal (3) tumorous brain[l(3)tb]. Classical genetic approaches relying on meiotic recombination and subsequent complementation with chromosomal deletions and gene mutations mapped the mutation to CG6169, the mRNA decapping protein 2 (DCP2), on the left arm of the third chromosome (3L), and thus the mutation was renamed asDCP2l(3)tb. Fine mapping of the mutation further identified the presence of aGypsy-LTR like sequence in the 5’UTR coding region ofDCP2, alongwith expansi...
Mutants provide an excellent platform for the discovery and characterization of gene functions. T... more Mutants provide an excellent platform for the discovery and characterization of gene functions. The present communication is a pioneering treatise on a hitherto undescribed function of the gene coding for the mRNA decapping protein 2 (DCP2) inDrosophila melanogaster. DCP2, the gene coding for the mRNA decapping enzyme, has been studied in various model organisms in the light of maintenance of transcript abundance and stability but has never been implicated in tumourigenesis. Herein, we describe the mapping and characterization of a novel tumour suppressor allele ofDCP2(CG6169), which we named aslethal(3)tumorous brain[l(3)tb]. The homozygous mutant individuals show prolonged larval life, develop larval brain tumors and are lethal in the larval/pupal stages. The tumour is characterized by the presence of increased number of superficial neuroblasts, abnormal chromosomal condensation and causes overgrowth in the wing and the eye-antennal discs of the homozygous mutant larvae, all of wh...
In the present study, we demonstrate that molecular chaperone Hsp70 and Hsc70 is essential for no... more In the present study, we demonstrate that molecular chaperone Hsp70 and Hsc70 is essential for normal organization and development of ommatidial cells in Drosophila melanogaster eye. An exogenously expressed dominant negative mutant of Hsp70 (K71E) and Hsc70.4 (K71S and D206S) in an eye-specific manner resulted in eye degeneration that includes loss of eye pigment, disorganized ommatidia, abnormality in bristle cell arrangement and reduction in the eye size. The developmental organization of ommatidial cells (cone, photoreceptor, pigment, and bristle cell complex) was disturbed in Hsp70 and Hsc70 mutants. Acridine orange (AO) and caspase 3 staining showed an increased cell death in Hsp70 and Hsc70 mutant eyes. Genetic interaction study of Hsp70 and Hsc70 mutants with candidate genes of JNK signaling pathway and immunocytochemistry study using phospho-JNK antibody suggested that mutation in Hsp70 and Hsc70 results in ectopic activation of JNK signaling in fly eye. Further, anti-PH3 s...
Spirulina (Arthrospira platensis) is a cyanobacterium (blue-green alga) consumed by humans and ot... more Spirulina (Arthrospira platensis) is a cyanobacterium (blue-green alga) consumed by humans and other animals because of its nutritional values and pharmacological properties. Apart from high protein contents, it also contains high levels of antioxidant and anti-inflammatory compounds, such as carotenoids, β-carotene, phycocyanin, and phycocyanobilin, indicating its possible pharmaco-therapeutic utility. In the present study using DJ-1β(Δ93) flies, a Parkinson's disease model in Drosophila, we have demonstrated the therapeutic effect of spirulina and its active component C-phycocyanin (C-PC) in the improvement of lifespan and locomotor behavior. Our findings indicate that dietary supplementation of spirulina significantly improves the lifespan and locomotor activity of paraquat-fed DJ-1β(Δ93) flies. Furthermore, supplementation of spirulina and C-PC individually and independently reduced the cellular stress marked by deregulating the expression of heat shock protein 70 and Jun-N-...
Industrialization and indiscriminate use of agrochemicals have increased the human health risk. R... more Industrialization and indiscriminate use of agrochemicals have increased the human health risk. Recent epidemiological studies raised a concern for male reproduction given their observations of reduced sperm counts and altered semen quality. Interestingly, environmental factors that include various metals, pesticides and their metabolites have been causally linked to such adversities by their presence in the semen at levels that correlate to infertility. The epidemiological observations were further supported by studies in animal models involving various chemicals. Therefore, in this review, we focused on male reproductive toxicity and the adverse effects of different environmental chemicals on male reproduction. However, it is beyond the scope of this review to provide a detailed appraisal of all of the environmental chemicals that have been associated with reproductive toxicity in animals. Here, we provided the evidence for reproductive adversities of some commonly encountered chemicals (pesticides/metals) in the environment. In view of the recent thrust for an alternate to animal models in research, we subsequently discussed the contributions of Drosophila melanogaster as an alternate animal model for quick screening of toxicants for their reproductive toxicity potential. Finally, we emphasized the genetic and molecular tools offered by Drosophila for understanding the mechanisms underlying the male reproductive toxicity.
The context-specific, complex issue of ‘vaccine hesitancy’ is explicated in terms of delay or ref... more The context-specific, complex issue of ‘vaccine hesitancy’ is explicated in terms of delay or refusal of vaccination despite the availability of vaccine services. Although eleven million beneficiaries were administered the COVID-19 vaccine in India from 16th January 2021 till 20th February 2021, however, proportionately a low turnout has been registered in various parts of the country, possibly attributable to hesitance/apprehension towards the current vaccination. In this backdrop, we report the response (collected between Feb 1, 2021 and Feb 15, 2021) of 358 voluntary respondents who participated in an online questionnaire-based pan-India survey, executed to assess their knowledge and acceptance towards the current COVID-19 vaccination program in its first phase. The survey questionnaire consisted of demographic characteristics of the respondents and queries pertaining to knowledge (7 items) and acceptance (3 items). The overall correct rate and the average knowledge score of the ...
Reactive oxygen species (ROS) generation within a cell is a natural process of specific subcellul... more Reactive oxygen species (ROS) generation within a cell is a natural process of specific subcellular components involved in redox reactions. Within a plant cell, chloroplasts are one of the major sources of ROS generation. Plastid‐generated ROS molecules include singlet oxygen (1O2), superoxide radical (O2–), hydroxyl radical (OH•) and hydrogen peroxide (H2O2), which are produced mainly during photochemical reactions of photosynthesis and chlorophyll biosynthetic process. Under normal growth and developmental, generated ROS molecules act as a secondary messenger controlling several metabolic reactions; however, perturbed environmental conditions lead to multi‐fold amplification of cellular ROS that eventually kill the target cell. To maintain homeostasis between production and scavenging of ROS, the cell has instituted several enzymatic and non‐enzymatic antioxidant machineries to maintain ROS at a physiological level. Among chloroplastic ROS molecules, excess generation of singlet o...
Miro (mitochondrial Rho GTPases), a mitochondrial outer membrane protein, facilitates mitochondri... more Miro (mitochondrial Rho GTPases), a mitochondrial outer membrane protein, facilitates mitochondrial axonal transport along the microtubules to facilitate neuronal function. It plays an important role in regulating mitochondrial dynamics (fusion and fission) and cellular energy generation. Thus, Miro might be associated with the key pathologies of several neurodegenerative diseases (NDs) including Alzheimer's disease (AD). In the present manuscript, we have demonstrated the possible genetic interaction between Miro and AD-related genes such as Tau, Aβ42 and Appl in Drosophila melanogaster. Ectopic expression of Tau, Aβ42 and Appl induced a rough eye phenotype, defects in phototaxis and climbing activity, and shortened lifespan in the flies. In our study, we have observed that overexpression of Miro improves the rough eye phenotype, behavioral activities (climbing and phototaxis) and ATP level in AD model flies. Further, the improvement examined in AD-related phenotypes was correl...
The use of transposons to create mutants has been the cornerstone ofDrosophilagenetics in the pas... more The use of transposons to create mutants has been the cornerstone ofDrosophilagenetics in the past few decades. Transpositions often create second-site mutations, devoid of transposon insertion and thereby affect subsequent phenotype analyses. In aP-element mutagenesis screen, a second site mutant was discovered on chromosome 3 wherein the homozygous mutant individuals show the classic hallmarks of mutations in tumor suppressor genes including brain tumour and lethality, hence the mutant line was initially named aslethal (3) tumorous brain[l(3)tb]. Classical genetic approaches relying on meiotic recombination and subsequent complementation with chromosomal deletions and gene mutations mapped the mutation to CG6169, the mRNA decapping protein 2 (DCP2), on the left arm of the third chromosome (3L), and thus the mutation was renamed asDCP2l(3)tb. Fine mapping of the mutation further identified the presence of aGypsy-LTR like sequence in the 5’UTR coding region ofDCP2, alongwith expansi...
Mutants provide an excellent platform for the discovery and characterization of gene functions. T... more Mutants provide an excellent platform for the discovery and characterization of gene functions. The present communication is a pioneering treatise on a hitherto undescribed function of the gene coding for the mRNA decapping protein 2 (DCP2) inDrosophila melanogaster. DCP2, the gene coding for the mRNA decapping enzyme, has been studied in various model organisms in the light of maintenance of transcript abundance and stability but has never been implicated in tumourigenesis. Herein, we describe the mapping and characterization of a novel tumour suppressor allele ofDCP2(CG6169), which we named aslethal(3)tumorous brain[l(3)tb]. The homozygous mutant individuals show prolonged larval life, develop larval brain tumors and are lethal in the larval/pupal stages. The tumour is characterized by the presence of increased number of superficial neuroblasts, abnormal chromosomal condensation and causes overgrowth in the wing and the eye-antennal discs of the homozygous mutant larvae, all of wh...
In the present study, we demonstrate that molecular chaperone Hsp70 and Hsc70 is essential for no... more In the present study, we demonstrate that molecular chaperone Hsp70 and Hsc70 is essential for normal organization and development of ommatidial cells in Drosophila melanogaster eye. An exogenously expressed dominant negative mutant of Hsp70 (K71E) and Hsc70.4 (K71S and D206S) in an eye-specific manner resulted in eye degeneration that includes loss of eye pigment, disorganized ommatidia, abnormality in bristle cell arrangement and reduction in the eye size. The developmental organization of ommatidial cells (cone, photoreceptor, pigment, and bristle cell complex) was disturbed in Hsp70 and Hsc70 mutants. Acridine orange (AO) and caspase 3 staining showed an increased cell death in Hsp70 and Hsc70 mutant eyes. Genetic interaction study of Hsp70 and Hsc70 mutants with candidate genes of JNK signaling pathway and immunocytochemistry study using phospho-JNK antibody suggested that mutation in Hsp70 and Hsc70 results in ectopic activation of JNK signaling in fly eye. Further, anti-PH3 s...
Spirulina (Arthrospira platensis) is a cyanobacterium (blue-green alga) consumed by humans and ot... more Spirulina (Arthrospira platensis) is a cyanobacterium (blue-green alga) consumed by humans and other animals because of its nutritional values and pharmacological properties. Apart from high protein contents, it also contains high levels of antioxidant and anti-inflammatory compounds, such as carotenoids, β-carotene, phycocyanin, and phycocyanobilin, indicating its possible pharmaco-therapeutic utility. In the present study using DJ-1β(Δ93) flies, a Parkinson's disease model in Drosophila, we have demonstrated the therapeutic effect of spirulina and its active component C-phycocyanin (C-PC) in the improvement of lifespan and locomotor behavior. Our findings indicate that dietary supplementation of spirulina significantly improves the lifespan and locomotor activity of paraquat-fed DJ-1β(Δ93) flies. Furthermore, supplementation of spirulina and C-PC individually and independently reduced the cellular stress marked by deregulating the expression of heat shock protein 70 and Jun-N-...
Industrialization and indiscriminate use of agrochemicals have increased the human health risk. R... more Industrialization and indiscriminate use of agrochemicals have increased the human health risk. Recent epidemiological studies raised a concern for male reproduction given their observations of reduced sperm counts and altered semen quality. Interestingly, environmental factors that include various metals, pesticides and their metabolites have been causally linked to such adversities by their presence in the semen at levels that correlate to infertility. The epidemiological observations were further supported by studies in animal models involving various chemicals. Therefore, in this review, we focused on male reproductive toxicity and the adverse effects of different environmental chemicals on male reproduction. However, it is beyond the scope of this review to provide a detailed appraisal of all of the environmental chemicals that have been associated with reproductive toxicity in animals. Here, we provided the evidence for reproductive adversities of some commonly encountered chemicals (pesticides/metals) in the environment. In view of the recent thrust for an alternate to animal models in research, we subsequently discussed the contributions of Drosophila melanogaster as an alternate animal model for quick screening of toxicants for their reproductive toxicity potential. Finally, we emphasized the genetic and molecular tools offered by Drosophila for understanding the mechanisms underlying the male reproductive toxicity.
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Papers by Anand Krishna Tiwari