pallavi chauhan

Inducible defences allow prey to increase survival chances when predators are present while avoiding unnecessary costs in their absence. Many studies report considerable inter-individual variation in inducible defence expression, yet what underlies this variation is poorly understood. A classic vertebrate example of a predator-induced morphological defence is the increased body depth in crucian carp (Carassius carassius), which reduces the risk of predation from gape-size limited predators. Here, we report that among-individual variation in morphological defence expression can be linked to sex. We documented sexual dimorphism in lakes in which crucian carp coexisted with predators, where females showed shallower relative body depths than males, but not in a predator-free lake. When exposing crucian carp from a population without predators to perceived predation risk in a laboratory environment (presence/absence of pike, Esox lucius), we found that males expressed significantly great...

The outcome of hybridization is of major interest in evolutionary and conservation biology. Here, we investigate (i) the genomic signal of the hybridization dynamics, (ii) the strength of reproductive barriers preventing copulation in heterospecific and hybrid crosses, and (iii) the population dynamics (stability of species proportions) of the two damselfly species Ischnura elegans and I. graellsii in two differently aged Spanish hybrid regions. RAD sequencing in these hybrid regions and in allopatric populations was used to generate 5,702 SNPs to quantify population diversity and population differentiation, and a subset of 381 species-specific SNPs to analyze individual ancestry and the proportion of individuals in different hybrid classes. Our individual ancestry results showed the presence of F1 and F2 hybrids, in line with on-going hybridization and bidirectional backcrossing in both hybrid regions, with almost complete absence of genetically pure I. elegans and I. graellsii. Di...

Many ectothermic species are currently expanding their distributions polewards due to anthropogenic global warming. Molecular genetic mechanisms facilitating range expansion under these conditions are largely unknown, but understanding these could help mitigate expanding pests and disease vectors, or help explain why some species fail to track changing climates. Here, using RNA-seq data, we examine genome-wide changes in gene expression under heat and cold stress in the range-expanding damselfly Ischnura elegans in northern Europe. We find that both the number of genes involved and levels of gene expression under heat stress have become attenuated during the expansion, consistent with a previously-reported release from selection on heat tolerances as species move polewards. Genes upregulated under cold stress differed between core and edge populations, corroborating previously-reported rapid adaptation to cooler climates at the expansion front. Expression of sixty-nine genes exhibit...

Figure S1. Volcano plots showing the expression difference of transcripts between males and females, and between males and each female morph (based on log2 fold change- and p-values listed in Additional file 1: Sheet 4â 7). Figure S2. Carotenoid pigmentation pathway. Figure S3. Juvenile hormone biosynthesis pathway. Figure S4. Sex determination pathway. (DOCX 265 kb)

Sheet 1. RNA sequence data trimming statistic. Sheet 2: Summary of initial and final de novo assembly. Sheet 3: 20 most abundant protein domain. Sheet 4–7: List of all transcripts with results from the differential expression analysis between all females and males (sheet 4), androchrome females and males (sheet 5), infuscans females and males (sheet 6), and infuscans-obsoleta females and males (sheet 7). Sheet 8–11: List of the most differentially expressed transcripts (DETs) between all females and males (sheet 8), androchrome females and males (sheet 9), infuscans females and males (sheet 10), and infuscans-obsoleta females and males (sheet 11). Sheet 12: List of enriched GO terms in DETs (based on the DETs listed in sheet 8–11). Sheet 13: Kegg pathways identified in DETs (based on the DETs listed in sheet 8). Sheet 14: List of different types of TRPs identified in the assembled transcriptome. Sheet 15: List of olfactory genes identified in the assembled transcriptome. Sheet 16: G...

Additional file 1: Table S1. Pairwise genetic distance between strains using MEGA X [91]. Table S2. List of the primers used in this study, and associated details. Table S3. GenBank accession numbers from additional sequences of the mitochondrial COI gene from diverse Ischnura species from different countries. Figure S1. The phylogeny of (A) ftsz gene and (B) wsp gene, separately

ABSTRACTContemporary hybrid zones act as natural laboratories for the investigation of species boundaries and allow to shed light on the little understood roles of sex chromosomes in species divergence. Sex chromosomes are considered to function as a hotspot of genetic divergence between species; indicated by less genomic introgression compared to autosomes during hybridisation. Moreover, they are thought to contribute to Haldane’s rule which states that hybrids of the heterogametic sex are more likely to be inviable or sterile. To test these hypotheses, we used contemporary hybrid zones of Ischnura elegans, a damselfly species that has been expanding its range into the northern and western regions of Spain, leading to chronic hybridization with its sister species Ischnura graellsii. We analysed genome-wide SNPs in the Spanish I. elegans and I. graellsii hybrid zone and found (i) that the X chromosome shows less genomic introgression compared to autosomes and (ii) that males are und...

Sex chromosomes have evolved from the same autosomes multiple times across vertebrates, suggesting that selection for recombination suppression has acted repeatedly and independently on certain genetic backgrounds. Here, we perform comparative genomics of a bird clade (larks and their sister lineage; Alaudidae and Panuridae) where multiple sex chromosome–autosome fusions appear to have formed expanded sex chromosomes. We detected the largest known avian sex chromosome (195.3 Mbp) and show that it originates from fusions between parts of four avian chromosomes: Z, 3, 4A and 5. Within these four chromosomes, we found evidence by using phylogenetic inference of five evolutionary strata where recombination had been suppressed at different time points, and showed that stratum age explained the divergence rate of Z–W gametologs. Next, we analysed chromosome content and found that chromosome 3 was significantly enriched for genes with predicted sex-related functions. Finally, we demonstrate extensive homology to sex chromosomes in other vertebrate lineages: chromosomes Z, 3, 4A and 5 have independently evolved into sex chromosomes in fish (Z), turtles (Z, 5), lizards (Z, 4A), mammals (Z, 4A) and frogs (Z, 3, 4A, 5). Our results provide insights in and support for repeated evolution of sex chromosomes in vertebrates.

Bioinformatics is a continuously evolving field since it came into existence and contributing significantly in all major areas of biological sciences. Advanced sequencing technologies and exponential growth in computational resources have facilitated the high-end bioinformatics application in various research areas such as microbiome research in biological system. Bioinformatics contributed significantly in the development of powerful methods and tools in metagenomics research through direct inspection of targeted and nontargeted DNA in environmental samples. Advances in metagenomics, high-throughput methods, tools, software, pipelines, databases and analysis products for the microbes and microbiome-related studies have shifted the field of microbiology from culturing and microscopy studies to DNA sequencing and bioinformatics analyses. In the last decade, various long-term research projects and studies have flooded the microbiome sequencing data and analyses. Now, microbial communi...

Background Evolutionary processes can cause strong spatial genetic signatures, such as local loss of genetic diversity, or conflicting histories from mitochondrial versus nuclear markers. Investigating these genetic patterns is important, as they may reveal obscured processes and players. The maternally inherited bacterium Wolbachia is among the most widespread symbionts in insects. Wolbachia typically spreads within host species by conferring direct fitness benefits, and/or by manipulating its host reproduction to favour infected over uninfected females. Under sufficient selective advantage, the mitochondrial haplotype associated with the favoured maternally-inherited symbiotic strains will spread (i.e. hitchhike), resulting in low mitochondrial genetic variation across the host species range. Method The common bluetail damselfly (Ischnura elegans: van der Linden, 1820) has recently emerged as a model organism for genetics and genomic signatures of range expansion during climate ch...

The evolution of sex chromosomes, and patterns of sex-biased gene expression and dosage compensation, are poorly known among early winged insects such as odonates. We assembled and annotated the genome of Ischnura elegans (blue-tailed damselfly), which, like other odonates, has a male-hemigametic sex-determining system (X0 males, XX females). By identifying X-linked genes in I. elegans and their orthologs in other insect genomes, we found homologies between the X chromosome in odonates and chromosomes of other orders, including the X chromosome in Coleoptera. Next, we showed balanced expression of X-linked genes between sexes in adult I. elegans, i.e. evidence of dosage compensation. Finally, among the genes in the sex-determining pathway only fruitless was found to be X-linked, while only doublesex showed sex-biased expression. This study reveals partly conserved sex chromosome synteny and independent evolution of dosage compensation among insect orders separated by several hundred million years of evolutionary history.

Sex chromosomes have evolved from the same autosomes multiple times across vertebrates, suggesting that selection for recombination suppression has acted repeatedly and independently on certain genetic backgrounds. Here, we perform comparative genomics of a bird clade (larks and their sister lineage; Alaudidae and Panuridae) where multiple autosome–sex chromosome fusions appear to have formed expanded sex chromosomes. We detected the largest known avian sex chromosome (195.3 Mbp) and show that it originates from fusions between parts of four avian chromosomes: Z, 3, 4A and 5. Within these four chromosomes, we found evidence of five evolutionary strata where recombination had been suppressed at different time points, and show that stratum age explained the divergence rate of Z–W gametologs. Next, we analysed chromosome content and found that chromosome 3 was significantly enriched for genes with predicted sex-related functions. Finally, we demonstrate extensive homology to sex chromo...

Non-recombining sex chromosomes (Y and W) accumulate deleterious mutations and degenerate. This poses a problem for the heterogametic sex (XY males; ZW females) because a single functional gene copy often implies less gene expression and a potential imbalance of crucial expression networks. Mammals counteract this by dosage compensation, resulting in equal sex chromosome expression in males and females, whereas birds show incomplete dosage compensation with significantly lower expression in females (ZW). Here, we study the evolution of Z and W sequence divergence and sex-specific gene expression in the common whitethroat (Sylvia communis), a species within the Sylvioidea clade where a neo-sex chromosome has been formed by a fusion between an autosome and the ancestral sex chromosome. In line with data from other birds, females had lower expression than males at the majority of sex-linked genes. Results from the neo-sex chromosome region showed that W gametologs have diverged functio...

ABSTRACTSex chromosomes have evolved from the same autosomes multiple times across vertebrates, suggesting that certain genomic regions are predisposed towards sex-linkage. However, to test this hypothesis detailed studies of independently originated sex-linked regions and their gene content are needed. Here we address this problem through comparative genomics of birds where multiple chromosomes appear to have formed neo-sex chromosomes: larks (Alaudidae; Sylvioidea). We detected the largest known avian sex chromosome (195.3 Mbp) and show that it originates from fusions between (parts of) four avian chromosomes (Z, 3, 4A and 5). We found evidence of five evolutionary strata where recombination has been suppressed at different time points, and that these time points correlate with the level of Z–W gametolog differentiation. We show that there is extensive homology to sex chromosomes in other vertebrate lineages: three of the fused chromosomes (Z, 4A, 5) have independently evolved int...

The human population is still facing appalling conditions due to several outbreaks of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) virus. The absence of specific drugs, appropriate vaccines for mutants, and knowledge of potential therapeutic agents makes this situation more difficult. Several 1, 2, 4-triazolo [1, 5-a] pyrimidine (TP)-derivative compounds were comprehensively studied for antiviral activities against RNA polymerase of HIV, HCV, and influenza viruses, and showed immense pharmacological interest. Therefore, TP-derivative compounds can be repurposed against the RNA-dependent RNA polymerase (RdRp) protein of SARS-CoV-2. In this study, a meta-analysis was performed to ensure the genomic variability and stability of the SARS-CoV-2 RdRp protein. The molecular docking of natural and synthetic TP compounds to RdRp and molecular dynamic (MD) simulations were performed to analyse the dynamic behaviour of TP compounds at the active site of the RdRp protein. TP com...

The nucleotide binding site leucine-rich repeats (NBSLRRs) belong to one of the largest known families of disease resistance genes that encode resistance proteins (R-protein) against the pathogens of plants. Various defence mechanisms have explained the regulation of plant immunity, but still, we have limited understanding about plant defence against different pathogens. Identification of R-proteins and proteins having R-protein-like features across the genome, transcriptome and proteome would be highly useful to develop the global understanding of plant defence mechanisms, but it is laborious and time-consuming task. Therefore, we have developed a support vector machine-based high-throughput pipeline called NBSPred to differentiate NBSLRR and NBSLRR-like protein from Non-NBSLRR proteins from genome, transcriptome and protein sequences. The pipeline was tested and validated with input sequences from three dicot and two monocot plants including Arabidopsis thaliana, Boechera stricta, Brachypodium distachyon Solanum lycopersicum and Zea mays. The NBSPred pipeline is available at http://soilecology.biol.lu.se/nbs/. Supplementary data are available at Bioinformatics online. sandeep.kushwaha@biol.lu.se.

Signaling pathways leading to wrinkle formation have demonstrated c-jun to be one of the most prominent target against wrinkle formation. Designing inhibitors for c-jun requires a complete 3D structure. In this report an attempt has been made to model 3D structure of c-jun by comparative homology modeling. Through homology modeling four models were constructed using single and multiple templates. Based on single template approach two models were constructed differing in loop modeling. In multiple templates (segment based approach) approach two models were constructed differing in target-template identity and loop modeling. The models developed were evaluated by PROCHECK, WHAT CHECK and calculated RMSD and RMSF values. Among all Models, model developed using multiple templates having more than 40% sequence identity and loop modeled by fold recognition was found to be the best model for 3D structure of protein c-jun.

Literature shows that various molecular cascades are activated by stress, UV rays and pollutants leading to wrinkle formation of the skin. These cascades start from five types of receptors (EGFR, PDGFR, PAFR, IL1R, TNFRB) and terminate with the production of matrix metalloproteinase's, which degrades collagen leading to wrinkle formation. Signaling pathway leading to wrinkle formation showed that c-jun is involved in these cascades. Therefore, c-jun is the preferential choice for inhibition to reduce the intensity of collagen degradation. Hence, the 3D structure of c-jun was modeled using segment based homology modeling by MODELLER 9v5. Evaluation of the constructed model was done by PROCHECK, WHAT CHECK and through RMSD/RMSF calculations. Ligands for the inhibitory sites were designed using LIGANDSCOUT. The interaction study of ligand and receptor was performed by AUTODOCK. A library of analogues was constructed for three known inhibitory sites. The receptor-analogue study was performed using the software MOLEGRO Virtual Docker. The analogues constructed from the designed novel reference ligands showed good binding with the receptor binding sites. It should be noted that these predicted data should be validated using suitable assays for further consideration.

Skin provides passage for the delivery of drugs. The in vitro and in vivo testing of chemicals for estimation of dermal absorption is very time consuming, costly and has many ethical difficulties related to human and animal testing. The solution to the problem is Quantitative structure-permeability relationships. This method relates dermal penetration properties of a range of chemical compounds to their physicochemical parameters. In the present study, an effort has been made to develop models for the accurate prediction of skin permeability using a large, diverse dataset through the combination of various regression methods coupled with the Genetic Algorithm (GA)/Interval Partial Least-Squares Algorithm (iPLS). The descriptors were calculated using e-DRAGON and ADME Pharma Algorithms-Abrahams descriptors. The original dataset was divided into a training set and a testing set using the Kennard-Stone Algorithm. The selection of descriptors was made by the GA and iPLS. The model applicability domain was determined. The results showed that a three-parameter model built through Partial Least-squares Regression was most accurate with r(2) of 0.936.

In the present scenario, wrinkle formation, prominent sign of skin ageing, is one of the most demanding areas of research. This burgeoning research demand to reduce, delay and restore the effects of skin ageing has led to the study of various signaling pathways leading to wrinkle formation. Wrinkles appear on skin due to influence of intrinsic and extrinsic factors on mitogenic reactions and signal transduction pathways. The aim of the present study is to analyze each protein involved in the signaling pathway leading to dilapidation of collagen and an attempt has been made to compare different signal transduction pathways to identify a common target for skin ageing. In the present work, bioinformatics tools have been used to extract information from already existing experimental data. The statistical techniques are used for further analysis and make useful predictions for skin ageing. Stressors like UV irradiation, osmotic stress and heat shock have been reported to activate epidermal growth factor receptor, interleukin 1 receptor, tumor necrosis factor receptor, platelet-derived growth factor receptor and platelet activation factor receptor signaling pathways, which lead to the production of matrix metalloproteinases, collagen degradation and, consequently, wrinkle formation. When all the five signaling pathways were modeled, the c-jun part of the AP-1 transcription factor was found to be a common intermediate protein involved in all the signaling cascades. Moreover, it shows differential expression in the skin on response to stressors. We proposed c-jun to be the most potent target for drug designing against wrinkle formation.