Biology subjects

Mishra, G.

Publications and source records attributed to Mishra, G..

At least 19 recordsLinked to original sources

bioRxiv2026

Relatedness and last male sperm precedence in Cheilomenes sexmaculata: Implications for inbreeding avoidance

Avoidance to mate with relatives is a common evolutionary strategy, as it helps maintain genetic diversity and overall fitness within populations. Females often prefer unrelated males to mitigate the risks associated with inbreeding, such as the expression of deleterious recessive alleles. This preference can involve various post-copulatory mechanisms through which females bias paternity towards males with potentially better genes. The phenomenon of last male sperm precedence, where the last male to mate with a female tends to sire the majority of offspring, is well-documented in ladybird beetles. However, how relatedness affects this phenomenon remains unclear. This study aims to investigate whether paternity share is altered when the last male to mate with a female is related to her. By conducting double mating experiments with two different morphs (typical and intermediate) as phenotypic markers, we seek to determine if relatedness disrupts last male sperm precedence. It was hypothesised that females of Cheilomenes sexmaculata will prefer unrelated males over related ones, irrespective of mating order, potentially breaking down the last male sperm precedence. This preference for unrelated males was reflected in our results with unrelated males exhibiting enhanced reproductive success. Females were more fecund and exhibited higher egg viability with unrelated males. Greater paternity share was observed for unrelated males when the second male was related to the female. This study highlights the dynamic nature of sperm precedence and the role of mate quality in female mate choice, emphasizing the importance of inbreeding avoidance in sexual selection.

zoology↗

bioRxiv2026

Myeloid IRF5 is required for TLR7-driven inflammatory hemophagocyte differentiation and Macrophage Activation Syndrome

In TLR7-driven macrophage activation syndrome (MAS), inflammatory hemophagocytes (iHPCs) differentiate from Ly6CHI monocytes, phagocytose red blood cells and promote disease, including anemia and thrombocytopenia. We demonstrate here that IRF5 is required for iHPC differentiation and MAS in TLR7-overexpressing (TLR7.1) mice. Both constitutive and myeloid-specific Irf5 deletion reduced iHPCs and improved anemia, thrombocytopenia and survival. Furthermore, therapeutic inhibition of IRF5 ameliorated MAS features and reduced splenic and circulating iHPCs. While cell-intrinsic IRF5 expression was required for iHPC differentiation, it was not required for TLR7.1 Ly6CHI monocyte differentiation and monocyte transcriptional programs. We further show that the transcriptome and chromatin landscape changed dramatically as iHPCs differentiated from TLR7.1 Ly6CHI monocytes. Many transcriptional programs gained in iHPCs were enriched in genes associated with IRF5-binding accessible chromatin regions, including those associated with NF-kB signaling, cytokine and chemokine production, and complement activation. Our data suggest that IRF5 collaborates with other transcription factor families, including NF-kB, ETS and AP1 members, to regulate iHPC gene programs. Together, our findings demonstrate that expression of IRF5 in myeloid cells is critical for MAS, for iHPC differentiation, and acts broadly across iHPC-specific gene programs in TLR7-driven inflammation.

immunology↗

bioRxiv2026

Lineage-specific chromatin poising enforced by ETS-IRF composite elements determines the divergent interferon responses of plasmacytoid dendritic cells and epithelial cells

Plasmacytoid dendritic cells (pDCs) produce robust type I interferons (IFN-I) within hours of viral sensing, while epithelial cells at mucosal surfaces mount a delayed response dominated by type III interferons (IFN-III). Both cell types express pattern recognition receptors that activate similar downstream transcription factors, yet they produce distinct subsets of IFNs. The mechanisms underlying these differences have remained unclear. Here, using Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq) in primary human pDCs and intestinal epithelial cells, we show that IFN-I and IFN-III gene loci carry opposing, constitutively established chromatin accessibility landscapes that determine cell-type-specific interferon induction. The IFN-I locus is broadly open in pDCs and constitutively closed in epithelial cells, while the IFN-III locus displays the reciprocal pattern. Motif enrichment analysis of accessible regions at the IFN-I locus in pDCs revealed unexpected and significant enrichment of ETS family binding motifs alongside IRF motifs, which determines the cell-type-specific locus accessibility. The ETS factor PU.1 and IRF8 bind IFN-I promoters, at composite ETS-IRF elements positioned at the Positive Regulatory Domain IV (PRDIV) site of IFNB1 promoter and adjacent to the TATA-proximal IRF motif of IFNA promoters. IFNL gene promoters lack ETS recognition sequences. PU.1-IRF8 composite factor binding extends across intergenic regions of the IFN-I locus, where candidate enhancer elements marked by H3K4me1, H3K27ac, and RNA Pol II occupancy were identified. We propose that this network of ETS-IRF composite-element-anchored enhancers maintains the IFN-I locus in a constitutively poised state in pDCs, licensing the rapid and robust IFN-I response that defines pDCs. In epithelial cells, the absence of PU.1 and IRF8 renders the IFN-I locus epigenetically silent, while the IFN-III locus is constitutively open. Despite this, the delayed IFN-III gene expression in epithelial cells is due to intrinsically weaker promoter activity relative to IFN-I. These findings reveal that the divergent IFN induction of pDCs and epithelial cells is determined by the chromatin architecture prior to infection. Overall, these observations show that lineage-specific ETS-IRF regulatory factors and promoter strength determine the cell-type-specific IFN activation.

immunology↗

bioRxiv2025

The Mitochondrial F-box protein 1 and DJ-1 homolog HSP31 support cellular proteostasis during mitochondrial protein import clogging

Mitochondrial biogenesis requires the import of [~]1,000-1,500 nuclear-encoded proteins across the Translocase of Outer Membrane (TOM) and the Translocase of Inner Membrane (TIM) 22 or 23 complexes. Protein import defects cannot only impair mitochondrial respiration but also cause mitochondrial Precursor Overaccumulation Stress (mPOS) in the cytosol. Recent studies showed that specific mutations in the nuclear-encoded Adenine Nucleotide Translocase 1 (ANT1) cause musculoskeletal and neurological diseases by clogging TOM and TIM22 and inducing mPOS. Here, we found that overexpression of MFB1, encoding the mitochondrial F-box protein 1, suppresses cell growth defect caused by a clogger allele of AAC2, the yeast homolog of Ant1. Disruption of MFB1 synergizes with a clogger allele of aac2 to inhibit cell growth. This is accompanied by increased retention of mitochondrial proteins in the cytosol, suggesting exacerbated defect in mitochondrial protein import. Proximity-dependent biotin identification (BioID) suggested that Mfb1 interacts with several mitochondrial surface proteins including Tom22, a component of the TOM complex. Loss of MFB1 under clogging conditions activates genes encoding cytosolic chaperones including HSP31. Interestingly, disruption of HSP31 creates a synthetic lethality with protein import clogging under respiring conditions. We propose that Mfb1 functions to maintain mitochondrial protein import competency under clogging conditions, whereas Hsp31 plays an important role in protecting the cytosol against mPOS. Mutations in DJ-1, the human homolog of Hsp31, and mitochondria-associated F-box proteins (eg., Fbxo7) are known to cause early-onset Parkinsons disease. Our work may help to better understand how these mutations affect cellular proteostasis and cause neurodegeneration.

genetics↗

bioRxiv2025

Plasmacytoid dendritic cells in the intestine preferentially produce interferon lambda at homeostasis contributing to tonic localized innate immune responses

The healthy intestine maintains homeostasis in part via immune responses to microbiota, which includes basal production of interferon cytokines. Previous work showed that Type III Interferon (IFN-{lambda}) stimulates localized pockets of interferon-stimulated genes (ISGs) in the adult mouse intestinal epithelium at homeostasis that provide preemptive protection from viral pathogens. Here, we demonstrate that a major source of homeostatic IFN-{lambda} production in the intestine is a population of epithelium-associated plasmacytoid dendritic cells (pDC). Depletion of bacterial microbiota in the intestine also reduces pDC abundance, and pDC depletion or bone marrow reconstitution with IFN-{lambda}-deficient pDC results in reduced expression of homeostatic ISGs in the intestinal epithelium. Notably, intestinal pDC preferentially produce IFN-{lambda} over Type I IFNs whereas splenic pDC produce more Type I IFNs. Comparison of intestinal and splenic pDC reveal tissue-specific changes in gene expression and genomic accessibility, including evidence of responses to transforming growth factor beta (TGF-{beta}) in the intestine. Isolated gut pDC produce more IFN-{lambda} than splenic pDC upon stimulation, and pre-treatment of a human pDC cell line with TGF-{beta} results in enhanced production of IFN-{lambda} upon stimulation. This study demonstrates that pDC are an important source of homeostatic IFN-{lambda} in the intestine and defines the role of barrier cytokine TGF-{beta} in regulating IFN types produced by pDC upon stimulation. Reprogramming of recruited pDC by tissue cytokines may have important implications for balancing effective antimicrobial responses with damaging inflammation at barrier tissues. One sentence summaryThis study demonstrates that pDC are an important source of homeostatic IFN-{lambda} in the intestine and defines the role of barrier cytokine TGF-{beta} in regulating IFN types produced by pDC upon stimulation.

immunology↗

bioRxiv2025

CELF2 suppresses endogenous RNA ligands that activate RIG-I-mediated interferon induction

Type I interferons (IFNs) are critical for the control of viral infections, but aberrant IFN expression can result in tissue damage. RIG-I-like receptors (RLRs), such as RIG-I and MDA5, sense viral RNA and signal through the adaptor protein MAVS to induce phosphorylation and nuclear translocation of the transcription factor IRF3, thereby driving IFN production. However, activation of RLRs by endogenous RNA ligands can also induce IFNs, leading to autoinflammation. Identifying factors that suppress endogenous RNA ligands is critical for preventing IFN-induced autoimmunity. In this study, we identify a novel regulator, CELF2, that suppresses endogenous RNAs that otherwise activate the RLR pathway. We uncovered a novel role for the splicing factor CELF2 as a suppressor of immunostimulatory endogenous RNA ligands. Depletion of CELF2 in macrophages led to a spontaneous IFN and IFN-stimulated gene signature, dependent on the RIG-I-MAVS pathway. Furthermore, the transfer of RNA from CELF2-depleted macrophages was sufficient to induce type I IFN expression in naive cells. This RNA was found to be double-stranded as RNase III treatment of RNA derived from CELF2-depleted cells ablated IFN induction in naive cells. Immunoprecipitation of double-stranded RNA from CELF2-depleted macrophages revealed several immunostimulatory RNAs, which contribute to the increased interferon-stimulated gene signature observed in CELF2-depleted macrophages. These data indicate that CELF2 suppresses endogenous RNA ligands, which could otherwise activate RIG-I and induce an IFN signature. Overall, these findings reveal that CELF2 is an important regulator of self-RNA ligands to prevent IFN-induced autoinflammation. One-sentence summaryCELF2 suppresses RIG-I-like receptor ligands that activate interferon.

immunology↗

bioRxiv2024

Automated microinjection for zebrafish xenograft models

Zebrafish xenograft models have been increasingly recognized for their ability to predict patient responses to cancer therapeutics, suggesting their potential as diagnostic tools in clinical settings. However, these models require the precise microinjection of cancer cell suspensions in many small and fragile zebrafish larvae. Manual injections are so challenging that, even after months of training, variability in experimental results persists among researchers. This limits the uptake and deployment of zebrafish xenograft models for clinical use and drug discovery. To address this challenge, we have designed, built, and validated an automated microinjection robot. Combined results of injections into the vasculature, perivitelline space, and hindbrain ventricle demonstrated an average injection success rate of approximately 60%, with a larvae survival rate exceeding 70%, comparable to manual injections using a traditional micromanipulator. Notably, the full automated mode was twice as fast as manual injections. This automation of the microinjection process significantly reduces the need for extensive personnel training while it enhances reproducibility, efficiency, and accuracy, paving the way for more extensive use of zebrafish xenograft models in drug discovery and patient diagnostics.

cancer biology↗

bioRxiv2024

The polyadenosine RNA binding protein Nab2 regulates alternative splicing and intron retention during Drosophila melanogaster brain development

The regulation of cell-specific gene expression patterns requires the coordinated actions of hundreds of proteins, including transcription factors, processing enzymes, and many RNA binding proteins (RBPs). RBPs often become associated with an mRNA immediately after its production and can coordinate processing and quality control steps. Since RBPs can regulate multiple post-transcriptional processing steps, mutations within RBP-encoding genes often lead to pleiotropic effects that alter the physiology of multiple cell types. Thus, identifying how an RBP functions during RNA processing can provide a better understanding of both tissue physiology and mechanisms of disease. In the current study, we investigated how the Drosophila RNA binding protein Nab2, an evolutionary conserved ortholog of human ZC3H14, coordinates mRNA splicing and polyadenylation. ZC3H14 loss in human patients has previously been linked to alterations in nervous system function and disease. Both fly Nab2 and vertebrate ZC3H14 bind to polyadenosine RNA and have been implicated in the control of poly(A) tail length. Here we show that Nab2 loss from developing fly brain tissue also causes widespread changes in alternative splicing and intron retention. Retained introns in Nab2 null larval brains are most often first introns, are surrounded by adenosine-rich sequences, and are often associated with extended poly(A) tails, suggesting that Nab2 coordinates the splicing and polyadenylation of target transcripts. Alterations in splicing patterns ultimately lead to changes in protein abundance in Nab2 null developing brains. Overall, these studies highlight the importance of Nab2 and ZC3H14 in the post-transcriptional regulation of gene expression and provide critical insight into how this family of RBPs coordinates RNA processing during brain development.

genetics↗

bioRxiv2024

Carbon nanoparticle exposure strengthens water-relation parameters by stimulating abscisic acid pathway and aquaporins genes in rice

Mechanism of action and molecular basis of positive growth effects including yield increase due to carbon nanoparticle (CNP) treatment in rice plants is dissected here. CNP at 500 -750 {micro}g/mL were found to be the optimum dosages showing best seedling growth. CNP treatment resulted increase in stomata size, gaseous exchange and water use efficiency along with decrease in stomata frequency, relative humidity, internal CO2 concentration. CNP treatment exerted cold tolerance in seedlings and water stress tolerance in reproductive stage. CNP-coupled with water uptake was found to be endocytosis mediated, although CNP uptake was not affected by endocytosis inhibitor application in roots. Genomic analysis resulted major involvement of ABA pathway and stomata size and frequency genes in Arabidopsis and rice. Elevated endogenous ABA in rice seedlings and flag leaves along with increased expression of ABA biosynthetic genes in Arabidopsis and rice AtNCED3, AtNCED6, OsNCED1 confirmed increased ABA synthesis. Negative regulators of ABA pathway, OsSNRK2 down-regulation and up-regulation of stomagen (OsEPFL9) reconfirmed ABAs involvement. CNP treatment resulted water stress tolerance by maintaining lower stomatal conductance, transpiration rate and higher relative water content. Increased ABA (OsSNRK1, OsSNRK2) and aquaporin (OsPIP2-5) genes expressions could explain the better water stress tolerance in rice plants treated with CNP. Altogether, due to thermomorphogenesis, down-regulation of Phytochrome B resulted altered the ABA pathway and stomatal distribution with size. These changes resulted improved water relation parameters and WUE showing improvement in yield. Detailed mechanism of action of CNP in abiotic stress tolerance can be exploited in in nano-agriculture.

plant biology↗

bioRxiv2023

Rapid long-distance migration of RPA on single stranded DNA occurs through intersegmental transfer utilizing multivalent interactions

Replication Protein A (RPA) is a single stranded DNA (ssDNA) binding protein that coordinates diverse DNA metabolic processes including DNA replication, repair, and recombination. RPA is a heterotrimeric protein with six functional oligosaccharide/oligonucleotide (OB) domains and flexible linkers. Flexibility enables RPA to adopt multiple configurations and is thought to modulate its function. Here, using single molecule confocal fluorescence microscopy combined with optical tweezers and coarse-grained molecular dynamics simulations, we investigated the diffusional migration of single RPA molecules on ssDNA under tension. The diffusion coefficient D is the highest (20,000 nucleotides2/s) at 3 pN tension and in 100 mM KCl and markedly decreases when tension or salt concentration increases. We attribute the tension effect to intersegmental transfer which is hindered by DNA stretching and the salt effect to an increase in binding site size and interaction energy of RPA-ssDNA. Our integrative study allowed us to estimate the size and frequency of intersegmental transfer events that occur through transient bridging of distant sites on DNA by multiple binding sites on RPA. Interestingly, deletion of RPA trimeric core still allowed significant ssDNA binding although the reduced contact area made RPA 15-fold more mobile. Finally, we characterized the effect of RPA crowding on RPA migration. These findings reveal how the high affinity RPA-ssDNA interactions are remodeled to yield access, a key step in several DNA metabolic processes. SignificanceReplication Protein A (RPA) binds to the exposed single stranded DNA (ssDNA) during DNA metabolism. RPA dynamics are essential to reposition RPA on ssDNA and recruit downstream proteins at the bound site. Here in this work, we perform a detailed biophysical study on dynamics of yeast RPA on ssDNA. We show that RPA can diffuse on ssDNA and is affected by tension and salt. Our observations are best explained by the intersegmental transfer model where RPA can transiently bridge two distant DNA segments for its migration over long distances. We further dissect the contributions of the trimerization core of RPA and other adjacent RPA molecules on RPA migration. This study provides detailed experimental and computational insights into RPA dynamics on ssDNA.

biophysics↗

bioRxiv2023

Do more food choices lead to bad decisions? A case study in predacious ladybird beetle, Propylea dissecta.

Understanding why animals choose one food over another is one of the key questions underlying the fields of behaviour ecology. This study aims to test if ladybird beetles, Propylea dissecta Mulsant (Coleoptera: Coccinellidae) can forage selectively for nutrients in order to redress specific nutritional imbalances to maximise their fitness. The general approach was, first, to manipulate the nutritional status of the predator by rearing them in five separate pre-treatment dietary groups from first instar larvae to newly emerged adult stage. Thereafter, we tested their feeding response to five different types of food, i.e., Aphis craccivora Koch, Aphis nerii Boyer de Fonsclombe, conspecific eggs, heterospecific eggs and mixed pollen grains, equidistantly placed in Petri dish. On the basis of newly emerged adults food choice, they were reared on the same diet for 10 days. Thereafter, adults were paired with their opposite sex (collected from stock culture reared on A. craccivora) and mating and reproductive parameters were recorded. Our results suggested that the variety of food did not affect the preference of ladybird beetle, P. dissecta. They tend to choose their natural diet, i.e., aphid in each dietary regime. We found that previous dietary regime significantly influences the mating and reproductive parameters of both the male and female except for the time to commence mating by the male. Food choices of adult beetles were found to significantly influence the time to commence mating, average fecundity and percent egg viability in males and the mating duration in females.

zoology↗

bioRxiv2023

Limb regeneration is blastema dependent in a ladybird beetle, Cheilomenes Sexmaculata (Fabricius)

Holometabolous insects undergoes metamorphosis which involves an intercalated pupal stage between larva and adult. The body plan of the adult is established during pupal stage and larval systems are de-differentiated and reorganized in insects undergoing complete metamorphosis. In ladybird beetles, limbs amputated in larval stages are regenerated in adults. This occurs during pupation. Given that changes in pupa are akin to embryogenesis, does the lost limbs are redeveloped as a part of metamorphosis or has some pre-patterning initiated prior pupation? To study this we hypothesised that limb regeneration in a holometabolous ladybird beetles, Cheilomenes sexmaculata is the result of the recapitulation of the embryonic gene programs in the pupa. To test this, we exposed third larval stages of C. sexmaculata to amputation and prior to amputation the tissues on the amputated site was scraped off every 24hrs. It was found that limb regeneration does not occur in the treatment where scrapping was done. Assuming that these epidermal cells correspond to blastema, for limb regeneration in ladybird beetles blastema is essential and does not occur in its absence.

developmental biology↗

bioRxiv2023

Heterospecific physical interference modulates the reproductive attributes of a ladybird beetle

Propylea dissecta and Cheilomenes sexmaculata (Coleoptera: Coccinellidae), are similar sized, co-ocurring aphidophagous insects that share common resources. We conducted the current study to observe the phenomenon of reproductive interference and effect of presence of heterospecific adults (C. sexmaculata) on the reproductive output of P. dissecta. For this, we used two reciprocal mating combinations of heterospecifics. The first heterospecific combination used P. dissecta males with C. sexmaculata females and the second heterospecific mating combination used P. dissecta females with C. sexmaculata males. To further examine the effect of C. sexmaculata male on P. dissecta female, we used mixed mating treatments (C. sexmaculata male with conspecific pair of P. dissecta). Our results suggested that (1) in the first heterospecific mating combination, mating did not commence between P. dissecta male C. sexmaculata female, while in the second heterospecific mating combination, mating was recorded between P. dissecta female and C. sexmaculata male, (2) C. sexmaculata male interferes the conspecific mating in P. dissecta through multiple mating attempts which resulted in reduced fitness and reproductive success of P. dissecta. Overall, we illustrated the negative effects of reproductive interference caused by C. sexmaculata on the reproductive output (fecundity and egg viability) of P. dissecta.

zoology↗

bioRxiv2022

Effect of victim relatedness on cannibalistic behaviour of ladybird beetle, Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae)

Cannibalism is taxonomically widespread and has a large impact on the individuals fitness and population dynamics. Thus, identifying how the rates of cannibalism are affected by different ecological cues is crucial for predicting species evolution and population dynamics. In current experiment, we investigated how victim relatedness affects the cannibalistic tendencies of different life stages of ladybird, Menochilus sexmaculatus, which is highly cannibalistic. We provided larval instars and newly emerged adults of M. sexmaculatus with a choice of sibling, half-sibling and non-sibling conspecific eggs as victim of cannibalism. First victim cannibalised and latency to cannibalise were observed along with total number of victims cannibalised after 24 hours. First preference of victim did not differ with life stages of the cannibals though the number of victims cannibalized did increase with advancement in stage. Percentage of total eggs cannibalised also varied significantly with life stage and victim relatedness. First and second instars tend to cannibalise more percentage of siblings and non-sibling eggs while third instars cannibalised more percentage of non-sibling eggs; fourth instars and adults on the other hand cannibalised highest percentage of eggs irrespective of their relatedness. Insignificant effect of victim relatedness was observed on latency to cannibalise eggs, though it varied significantly with the cannibals life stage. Shortest latency to cannibalise was recorded for first instars and longest for adults and second instars. In conclusion, kin recognition and its avoidance is stage-specific, with fourth instar and newly emerged adults being less discriminatory as compared to early stages owing to increased evolutionary survival pressure.

zoology↗

bioRxiv2021

Real Time Face Recognition with limited training data: Feature Transfer Learning integrating CNN and Sparse Approximation

It is highly challenging to obtain high performance with limited and unconstrained data in real time face recognition applications. Sparse Approximation is a fast and computationally efficient method for the above application as it requires no training time as compared to deep learning methods. It eliminates the training time by assuming that the test image can be approximated by the sum of individual contributions of the training images from different classes and the class with maximum contribution is closest to the test image. The efficiency of the Sparse Approximation method can be further increased by providing high quality features as input for classification. Hence, we propose to integrate pre-trained CNN architecture to extract the highly discriminative features from the image dataset for Sparse classification. The proposed approach provides better performance even for one training image per class in complex environment as compared to the existing methods. Highlight of the present approach is the results obtained for LFW dataset with one and thirteen training images per class are 84.86% and 96.14% respectively, whereas the existing deep learning methods use a large amount of training data to achieve comparable results.

neuroscience↗

bioRxiv2020

Limb regeneration modulates reproductive attributes in ladybirds: A case study in Propylea dissecta and Coccinella septempunctata

Regeneration is the capability to regrow or repair the lost or injured body parts. In holometabolous insects, the adult development undergoes through larval and pupal stages. Literature revealed that the limb regeneration has various impact on different life traits of organisms. In the present study, we investigated limb regeneration of two different sized ladybirds affect their life attributes. Fourth instar larvae of small ladybird Propylea dissecta and the large ladybird Coccinella septempunctata were taken from the laboratory stock and were given an ablation treatment, viz. forelegs of larvae were amputated at the base of the coxa. Amputated larvae were observed until the adult emergence. Emerged adults were grouped in different categories on the basis limb regeneration i.e. regenerated adults (incomplete regenerated in case of P. dissecta), unregenerated, and normal (control) adults. These adults were kept in different mating treatments. The unregenerated adults of both the ladybirds took more time to commence mating with shorter copulation duration and reduced fecundity and percent egg viability. Thus, it can be concluded that regeneration ability modulates the life attributes of the ladybirds irrespective of their body size.

zoology↗

bioRxiv2020

Mating system modulates mate selection in aphidophagous ladybird beetle, Menochilus sexmaculatus

ABSTRACTMate competition and selection of mates is strongly influenced by the organism’s mating system. Monogamous matings provide more benefits as compared to polygamous matings. However, it has been proven that in polygamous systems, females gain benefits from the males, therefore indulging in multiple mating, leading males to access maximum females. In zigzag ladybird, Menochilus sexmaculatus, mate choice has been studied on several pre-and postcopulatory factors. However, mate choice as a function of mating system is still remains untouched. In the present study, we hypothesised that the mating system modulates mate selection of beetles. Adults were held in different mating systems and then males and females were tested in mate choice trials. Polygynous males were more preferred over monogynous males. However, males preferred monandrous females over polyandrous females. In a second experiment, we also included relatedness as additional factor. In female mate choice trials, females preferred unrelated monogynous males which were earlier rejected over related polygynous and in male mate choice trials, males preferred unrelated polyandrous females over related monandrous females. The results were not confined only to mate choice but significant effect was also observed on time to commence mating, copulation duration, fecundity and percent egg viability.View Full Text

zoology↗

bioRxiv2020

Effect of egg cannibalism on mating preferences and reproductive fitness of Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae)

Cannibalism has been reported in a large proportion of coccinellids in fields as well as in laboratories but studies involving mate preferences and potential benefits of cannibalism on reproduction in Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae)have yet not been done. Thus, we assessed the effect of conspecific egg cannibalism on mate preferences and reproductive outputs including offspring development. Higher mate preferences were recorded for non-cannibal mates (fed on A. craccivora) than cannibal ones (fed on conspecific eggs). Mating parameters significantly influenced by cannibalism. Time to commence mating lasted less for homogeneous diet pairs than heterogeneous diet pairs. Longer copulation duration and higher fecundity were recorded when one of the individuals in mating pair or both was a non-cannibal. Egg viability did not differed significantly in all reciprocal crosses. Total developmental durations of offspring were similar for all mating pairs.

animal behavior and cognition↗