Biology subjects

Goyal, N.

Publications and source records attributed to Goyal, N..

13 recordsLinked to original sources

bioRxiv2026

Disparities in avian genomic resources highlight gaps across the Global South

Avian genomes have proliferated rapidly in recent years while expanding our knowledge of genomic evolution. However, evaluating bird sampling across the tree of life and across their distributions is necessary to assess their contributions to global bird diversity and diversification patterns. We evaluated all available avian genome assemblies across geography, taxonomy, conservation status, and time. The 1,712 species with at least one genome assembly represent only ~15% of recognized avian diversity. Although all orders were represented, 24 bird families (all restricted to the Global South) lacked any genome assembly, and only ~37% (N= 2,397) of recognized genera had genomic representation. Nearly 78% of the most evolutionarily distinct and globally endangered (EDGE) lineages lacked a genome. Genomic resources are concentrated in temperate regions of the Global North, whereas species-rich tropical regions in Africa, South America, and Southeast Asia remain severely underrepresented relative to their diversity. Even after accounting for conservation status, evolutionary distinctiveness, and ecology, Global South species had roughly fourfold lower odds of having a genome than Global North species. Notably, the post-2021 surge in genome sequencing has counter-intuitively widened this gap. Together, our results highlight persistent gaps in genomic resources across the Global South and the need to collectively address these global knowledge gaps via collaborative efforts.

genomics↗

bioRxiv2026

Mimicin, an antimicrobial protein encoded by mimivirus

Antimicrobial peptides (AMPs) are innate defense molecules found in all domains of life. Giant viruses of amoeba are known to thrive among complex microbial relationships within its hosts cells, hinting at the existence of virus-derived antimicrobial strategies. Here we show that viruses belonging to the Mimiviridae and Marseilleviridae families contain a higher density of in silico predicted AMPs per genome size than other viruses of amoeba. The investigation of potential AMPs led to the description of Mimicin, a taxonomically restricted 74 amino acid long protein coded by few mimiviruses. Mimicin contains three smaller predicted AMP sequences within it and has a broad in vitro antimicrobial activity against different bacteria, a yeast and two non-enveloped phages. In contrast, it has no activity against a marseillevirus, a mimivirus or human cell lines. When tested against bacterial endosymbionts co-cultured with Acanthamoeba terricola, Mimicin and its SIM-31 portion were able to control the attenuated Protochlamydia amoebophila but not the highly virulent Parachlamydia acanthamoebae. Based on deposited transcriptomic data, Mimicin is coded by an early gene more active during the beginning of the infection process. No structure could be predicted using Alphafold, while additional structural analysis indicate that Mimicin could be a highly disordered protein. In conclusion, we describe evidence of a biologically relevant antimicrobial activity derived from a giant virus. Mimicin highlights the relevance of AMPs from giant viruses for microbial ecology and opens the way for investigating their biotechnological and clinical potential.

microbiology↗

bioRxiv2026

Real Science Is Harder Than Benchmarks: Evaluating Advanced AI Frameworks on Published Studies. II. Antibody Properties, Lipid-RNA Interactions

Artificial Intelligence (AI) frameworks for automating scientific research have shown strong performance on benchmarks, but their utility for real-world industrial research remains insufficiently characterized. Extending the analysis presented in the first paper of this series, we evaluated the same five advanced AI research frameworks (Kosmos, K-Dense, ToolUniverse, BioAgents from bio.xyz, and the AI Scientist-v2 from Sakana AI) on two more projects of high practical importance for biopharmaceutical development: predicting antibody developability properties with the use of pretrained protein language model embeddings, and modeling non-covalent lipid-RNA interactions in lipid nanoparticles with all-atom molecular dynamics (MD) simulations. The AI frameworks again showed genuine strengths, including unprompted identification of subtle methodological issues, successful use of pretrained protein embeddings, and consistent reporting of p-values and confidence intervals often absent from the original papers. However, no framework approached the scope of the original studies, and severe failures and hallucinations were observed. Our results confirm and extend the conclusion of the first paper that real published research from pharmaceutical companies that we tried to reproduce proved to be considerably harder for current AI frameworks than standard benchmarks suggest.

bioinformatics↗

bioRxiv2025

Distinct, asynchronous processes underlie cultural and genetic variation in a bird species with a complex song repertoire

Dialects in birdsongs represent population clusters and cultural diversity. Cultural and genetic variation in animals, however, do not always evolve along the same trajectory. Few studies have tested this in a wild songbird with a continuous learning strategy. Songbirds (oscine Passeriformes) with a continual learning window exhibit great song diversity and may show cultural differentiation that outpaces genetic divergence. We investigate cultural and genetic variation in a tropical endemic songbird in a topographically and climatically complex sky-island landscape of the Western Ghats of India. We combine fine-scale acoustic, behavioural, and genetic data: from 90 individuals (10,816 songs), analysed using frequency-temporal parameters and a linguistic method for syntax; a playback experiment with 136 trials to compare behavioural responses to local and non-local songs; and blood samples from 242 individuals (10,638 SNPs) to infer genetic population structure. We find no difference in songs across locations and individuals in the time-frequency domain, but only in syntax. One-third of notes, the smallest vocal units, are widely shared across all individuals in their distribution. Longer note combinations result in greater individual differences within populations, but only form small differences between populations. Geographic distance strongly predicts genetic but not song syntactic differences, and playback experiments show equal responses to local and non-local songs. Thus, strong individual signatures but weak local-level dialects are generated by a shared note repertoire and associated combinatorial syntax. We highlight that cultural transmission may operate at fine social scales, decoupled from genetic structure, which is strongly driven by isolation-by-distance. Significance statementWhether learned behaviours exhibit patterns similar to those of inherited genes remains a long-standing question in evolutionary biology. Birdsong has a strong cultural component paralleling human language, yet most knowledge comes from birds with a narrow learning window. Open-ended learners, who acquire new songs throughout life like humans, are poorly documented in the wild. We studied such a songbird restricted to the tropical cloud montane forests of southern India. Songs appear acoustically similar across populations but differ in how basic units are ordered (syntax), while individuals are more distinct from each other in longer note combinations than populations are. Genetic similarity decreased with geographic distance. Culturally learned traits can thus evolve independently of genetic structure, showing how learning decouples behaviour from geography-driven genetic ancestry.

evolutionary biology↗

bioRxiv2025

Using phylogenetic relationships to assess conservation priorities for birds in India

In the midst of the ongoing biodiversity crisis, setting conservation priorities has moved beyond the conventional approaches. The need to incorporate phylogeny-based metrics that capture evolutionary rarity with extinction risk for prioritization of global conservation efforts has been widely recognized. Such metrics are even more important in megadiverse countries of the Global South, where conservation spending is limited despite high conservation value. Here, we reassess global avian threatened evolutionary history with an updated phylogeny, using the EDGE metric. The EDGE metric or score combines evolutionary distinctiveness of a species with its extinction risk. We focus on India to identify species and regions that represent high avian EDGE scores. We find that the Bengal Florican (Houbaropsis bengalensis) had the highest median EDGE score of 18.83 MY (millions of years). To identify spatial conservation priorities, we mapped avian EDGE scores at a 10 km x 10 km scale. Northeastern India is exceptional in its richness of evolutionary unique and threatened species. We also scored IBAs and PAs, finding that IBA, as well as PA, with the maximum EDGE score, was Intaki or Ntangki National Park in Nagaland, accumulating [~]250 MY of threatened evolutionary history in India. Habitats of the top 5% of EDGE species in India are currently not adequately protected. Our study offers a preliminary basis for a quantitatively informed and phylogeny-driven conservation prioritization approach for researchers, practitioners, and policymakers to safeguard threatened evolutionary history of birds in India.

evolutionary biology↗

bioRxiv2025

Genome assemblies for seven families of birds from the Global South

Tropical regions are biodiversity-rich, yet remain underrepresented in the availability of genomic resources, as is evident in the Western Ghats of India, a biodiversity hotspot with high endemism. Here, we present high-quality, de novo genome assemblies for seven birds, representing seven families distributed in the Western Ghats: Black-naped Monarch (Monarchidae: Hypothymis azurea), Indian Yellow Tit (Paridae: Machlolophus aplonotus), Brown-cheeked Fulvetta (Leiothrichidae: Alcippe poioicephala), Malabar Trogon (Trogonidae: Harpactes fasciatus), Blue-bearded Bee-eater (Meropidae: Nyctyornis athertoni), Malabar Whistling-Thrush (Muscicapidae: Myophonus horsfieldii), Orange-headed Thrush (Turdidae: Geokichla citrina). Using a hybrid Oxford Nanopore long reads - Illumina short reads approach, we assembled genomes with sizes ranging from 1.03 to 1.13 Gbp. All assemblies demonstrated high contiguity and completeness (BUSCO scores >97%, UCEs >4799). Repeat masking identified [~]10% of the genomes as interspersed repeats, and functional annotations yielded an average of 9,619 protein-coding genes per species. Comparative analysis showed our assemblies had significantly higher contiguity than the median of existing avian genomes on NCBI (Wilcoxson test, p = 0.00226). Our genome assemblies fill a key geographic and taxonomic gap in the genomic data and provide a foundational resource for evolutionary and ecological research in the Old-World tropics.

genomics↗

bioRxiv2025

Spatial patterns of diversity in forest birds of peninsular India

Biodiversity is structured via complex interactions among ecological, geological, and climatic processes. Regions with high heterogeneity in climate and topography are known to harbor fine scale patterns in diversity which are often overlooked in global scale analyses. Here, we investigate spatial phylogenetic patterns of forest bird diversity across peninsular India, a region with high topographic and climatic heterogeneity. Using a comprehensive global bird phylogeny, we employ metrics such as Phylogenetic Diversity (PD), Phylogenetic Endemism (PE), and their relative forms (RPD, RPE) to quantify evolutionary history and endemism of forest birds in peninsular India. We examine the roles of contemporary climate, historic climatic stability, and topography in shaping these patterns. Our results reveal a strong gradient in diversity, with the southern Western Ghats acting as a major hotspot for both taxonomic and phylogenetic diversity and endemism. We detect distinct ecological and phylogenetic community structures across the peninsula, likely shaped by regional species pools and biogeographic barriers. Areas with greater topographic complexity, higher precipitation, and greater historic climatic stability were found to support high diversity. Our study provides critical insights for biogeography in this understudied yet highly biodiverse region for forest birds.

ecology↗

bioRxiv2024

State of India's Birds 2023: A framework to leverage semi-structured citizen science for bird conservation

Birds and their habitats are threatened with extinction around the world. Regional assessments of the State of Birds are a vital means to prioritize data-driven conservation action by informing national and global policy. Such evaluations have traditionally relied on data derived from extensive, long-term, systematic surveys that require significant resources, limiting their feasibility to a few regions in the world. In the absence of such structured long-term datasets, semi-structured datasets have recently emerged as a promising alternative in other regions around the world. Semi-structured data are generated and uploaded by birdwatchers to citizen science platforms like eBird. Such data contain inherent biases because birdwatchers are not required to adhere to a fixed protocol. An evaluation of the status of birds from semi-structured data is therefore a difficult task that requires careful curation of data and the use of robust statistical methods to reduce errors and biases. In this paper, we present a methodology that was developed for this purpose, and was applied to produce the comprehensive State of Indias Birds (SoIB) 2023 report. SoIB 2023 assessed the status of 942 bird species in India by evaluating each species based on three metrics: 1) long-term change: change in abundance between the year 2022 and the year-interval pre-2000; 2) current annual trend: mean annual change in abundance from 2015 to 2022; and 3) distribution range size. We found evidence that 204 species have declined in the long term, and 142 species are currently declining. We present and discuss important insights about Indias birds that can guide research and conservation action in the region. We hope that the detailed methodology described here can act as a blueprint to produce State of Birds assessments from semi-structured citizen science datasets and springboard conservation action in many other regions where structured data is lacking but strong communities of birders exist. Open Research StatementThe primary data are already publicly available on eBird (Sullivan et al. 2014), and other data are already published in a GitHub repository (stateofindiasbirds 2024).

ecology↗

bioRxiv2024

High-quality genome assembly of the endemic threatened White-bellied Sholakili Sholicola albiventris (Muscicapidae: Blanford, 1868) from the Shola Sky Islands, India.

The White-bellied Sholakili (Sholicola albiventris) is an endemic, elevational restricted species occurring in the Shola Sky Islands of the Western Ghats of India. This unique understory bird, with a complex vocal repertoire, exhibits impacts of gene flow due to anthropogenic habitat fragmentation. Here, we present the first genome assembly for Sholicola albiventris, which was assembled using a combination of Nanopore and Illumina sequences. The final assembly is 1.083 Gbp, consisting of 975 scaffolds with an N50 of 68.64Mbp and L50 of 6. Our genome assemblys completeness is supported by a high number of BUSCOs (99.9%) and a total of 4887 ultraconserved element (UCE) loci retrieved. We also report the complete mitochondrial genome comprising 13 protein-coding genes, 22 tRNAs, and 2 rRNAs. We identified 11.82% of the nuclear genome as repetitive and 36,000 putative genes, with 12017 genes functionally annotated. Our assembly showed a great synteny between Taeniopygia guttata and Gallus gallus chromosome level assemblies. This reference will be pivotal for investigating landscape connectivity, sub-population genetics, local adaptation, and conservation genetics of this high-elevation, range-restricted endemic bird species.

genomics↗

bioRxiv2024

Cyclic di-AMP regulates genome stability and drug resistance in Mycobacterium through RecA-dependent and -independent recombination

In Escherichia coli, RecA plays a central role in the rescue of stalled replication forks, double-strand break (DSB) repair, homologous recombination (HR) and induction of the SOS response. While the RecA-dependent pathway is dominant, alternative HR pathways that function independently of RecA do exist, but relatively little is known about the underlying mechanism. Several studies have documented that a variety of proteins act either as positive or negative regulators of RecA to ensure high-fidelity HR and genomic stability. Along these lines, we previously demonstrated that the second messenger cyclic di-AMP binds to mycobacterial RecA proteins, but not E. coli RecA, and inhibits its DNA strand exchange activity in vitro via the disassembly of RecA nucleoprotein filaments. Herein, we demonstrate that Mycobacterium smegmatis {Delta}disA cells, which lack c-di-AMP, exhibit increased DNA recombination, higher frequency of mutation and gene duplications during RecA-dependent and RecA-independent DSB repair. We also found that c-di-AMP regulates SOS response by inhibiting RecA-mediated self-cleavage of LexA repressor and its absence enhances drug resistance in M. smegmatis {Delta}disA cells. Together, our results uncover a role of c-di-AMP in the maintenance of genomic stability through modulation of DSB repair in M. smegmatis. SignificanceCyclic di-AMP is a second messenger present in bacteria and archaea and is implicated in a variety of functions in the cell, including DNA repair, cell wall metabolism, virulence, and gene expression. We show here that it maintains genome stability in Mycobacterium by regulating RecA-dependent and -independent DNA recombination pathways. It also regulates SOS response by inhibiting the self-cleavage of LexA by mycobacterial RecA. Absence of c-di-AMP leads to higher drug resistance in Mycobacterium.

molecular biology↗

bioRxiv2024

In-silico evaluation of Mirror repeats in some selected genes ofCandida albicans

All cellular processes in a living cell are controlled by its genetic material. DNA in majority of the domains acts as a regulatory molecule by controlling various vital functions. The genetic makeup of DNA or RNA (in viruses) is unique in all the domains. Their uniqueness is determined by the presence of various types of repetitive patterns of bases. These includes inverted repeats, tandem repeats, VNTRs, palindromes etc. Among many repetitive pattern types, Mirror repeats (MR) found to be dispersed throughout the genes or genomes. These sequences are associated with various functional features like their involvement in H-DNA formation, in replication & transcription, nervous system related diseases development etc. The major focus of this investigation is to identify MR sequences from some selected genes of Candida albicans using a bioinformatics based pipeline. The approach refers to as FPCB which utilized some manual steps to extract out MR sequence from any targeted gene or genome. The current study find out that the identified Mirror repeats found to be dispersed throughout the selected genes along with variable length. Among them the maximum & minimum MR sequences were reported in the gene FAS2 (108) & HIS1 (15) respectively. The present study will be helpful to provide a new insight for molecular as well as computational based studies of Candida albicans as well as other related fungal groups.

bioinformatics↗

bioRxiv2021

Molecular diversity and lineage commitment of human interneuron progenitors

Cortical interneurons are indispensable for proper function of neocortical circuits. Changes in interneuron development and function are implicated in human disorders, such as autism spectrum disorder and epilepsy. In order to understand human-specific features of cortical development as well as the origins of neurodevelopmental disorders it is crucial to identify the molecular programs underlying human interneuron development and subtype specification. Recent studies have explored gene expression programs underlying mouse interneuron specification and maturation. We applied single-cell RNA sequencing to samples of second trimester human ganglionic eminence and developing cortex to identify molecularly defined subtypes of human interneuron progenitors and immature interneurons. In addition, we integrated this data from the developing human ganglionic eminences and neocortex with single-nucleus RNA-seq of adult cortical interneurons in order to elucidate dynamic molecular changes associated with commitment of progenitors and immature interneurons to mature interneuron subtypes. By comparing our data with published mouse single-cell genomic data, we discover a number of divergent gene expression programs that distinguish human interneuron progenitors from mouse. Moreover, we find that a number of transcription factors expressed during prenatal development become restricted to adult interneuron subtypes in the human but not the mouse, and these adult interneurons express species- and lineage-specific cell adhesion and synaptic genes. Therefore, our study highlights that despite the similarity of main principles of cortical interneuron development and lineage commitment between mouse and human, human interneuron genesis and subtype specification is guided by species-specific gene programs, contributing to human-specific features of cortical inhibitory interneurons.

neuroscience↗

bioRxiv2020

Computationally replicating the Smith et al. (2015) positive-negative mode linking functional connectivity and subject measures

Understanding brain functionality and predicting human behavior based on functional brain activity is a major goal of neuroscience. Numerous studies have been conducted to investigate the relationship between functional brain activity and attention, subject characteristics, autism, psychiatric disorders, and more. By modeling brain activity data as networks, researchers can leverage the mathematical tools of graph and network theory to probe these relationships. In their landmark study, Smith et al. (2015) analyzed the relationship of young adult connectomes and subject measures, using data from the Human Connectome Project (HCP). Using canonical correlation analysis (CCA), Smith et al. found that there was a single prominent CCA mode which explained a statistically significant percentage of the observed variance in connectomes and subject measures. They also found a strong positive correlation of 0.87 between the primary CCA mode connectome and subject measure weights. In this study, we computationally replicate the findings of the original study in both the HCP 500 and HCP 1200 subject releases. The exact computational replication in the HCP 500 dataset was a success, validating our analysis pipeline for extension studies. The extended replication in the larger HCP 1200 dataset was partially successful and demonstrated a dominant primary mode.

neuroscience↗