Biology subjects

Ready, J.

Publications and source records attributed to Ready, J..

4 recordsLinked to original sources

bioRxiv2025

Hidden Diversity of Threatened Sharks and Rays in the Global Meat Trade

International wildlife trade is a major source of biodiversity loss, yet many species lie hidden within aggregated data that conceals trade impacts. We overcome this problem for the largest vertebrate wildlife trade globally - shark and ray meat - comprising 438 538 mt yr-1 across more than 150 species, 76% of which are Threatened. Revealed trade contains greater quantities of skates (+10%), hammerheads (+8%), and smoothhounds, dogfishes & tope (+5%), and fewer pelagic sharks (-38%) than previously known. Shorttail yellownose skate, smoothound, silky, mako, and blue sharks are the most underreported meat species, due to aggregated landings from China, Argentina, Japan, and Indonesia, demonstrating international trade in shark and ray meat as a diverse, pervasive, and previously hidden source of fishing mortality for many threatened species.

ecology↗

bioRxiv2025

A genome-scale drug discovery pipeline uncovers new therapeutic targets and a unique p97 allosteric binding site in Schistosoma mansoni

Schistosomes are parasitic flatworms that infect more than 200 million people globally. However, there is a shortage of molecular tools that enable the discovery of potential drug targets within schistosomes. Thus, praziquantel has remained the frontline treatment for schistosomiasis despite known liabilities. Here, we have conducted a genome-wide study in S. mansoni using the human druggable genome as a bioinformatic template to identify essential genes within schistosomes bearing similarity to catalogued drug targets. Then, we assessed these candidate targets in silico using a set of unbiased criteria to determine which possess ideal characteristics for a ready-made drug discovery campaign. Following this prioritization, we pursued a parasite p97 ortholog as a bona-fide drug target for the development of therapeutics to treat schistosomiasis. From this effort, we identified a covalent inhibitor series that kills schistosomes through an on-target killing mechanism by disrupting the ubiquitin proteasome system. Fascinatingly, these inhibitors induce a conformational change in the conserved D2 domain P-loop of schistosome p97 upon modification of Cys519. This conformational change reveals an allosteric binding site adjacent to the D2 domain active site reminiscent of the DFG flip in protein kinases. This allosteric binding site can potentially be utilized to generate new classes of species-selective p97 inhibitors. Furthermore, these studies provide a resource for the development of alternative therapeutics for schistosomiasis and a workflow to identify potential drug targets in similar systems with few available molecular tools. Significance StatementSchistosomes cause widespread infections in humans, leading to severe chronic illnesses in endemic regions. There is no vaccine for schistosomiasis, and there has been limited success using the current standard-of-care treatment, praziquantel. Therefore, it is essential to identify drug targets within these parasites. Here, we identify potential drug targets in schistosomes bearing similarity to established human therapeutic targets, evaluate their essentiality for parasite survival, then prioritize them using an unbiased set of criteria to uncover high-value targets for the treatment of schistosomiasis. We investigated one candidate as a proof-of concept, a p97 ortholog, to discover newly characterized inhibitors of the parasite enzyme. This study demonstrates that this workflow can lead to the identification of small molecules that kill schistosomes.

microbiology↗

bioRxiv2025

Müllerian mimicry in Neotropical butterflies: One mimicry ring to bring them all, and in the jungle bind them

Understanding the mechanisms underlying species distributions and coexistence is essential to predict and prevent the impacts of global change, particularly in biodiversity hotspots. However, the effects of biotic interactions may be challenging to investigate at large spatial scales. Leveraging well-characterized Mullerian mimetic systems in Neotropical butterflies, we investigated spatial patterns of mutualistic mimetic interactions within and between two tribes of aposematic Nymphalid butterflies: the Heliconiini (Heliconiinae) and the Ithomiini (Danainae). Despite 85 My of independent evolutionary histories, many species share similar warning wing patterns across the Neotropics. In this study we show that both tribes form similar biodiversity hotspots with a high prevalence of rare species and mimetic patterns in the tropical Andes. However, we reveal a higher relative richness of heliconiine butterflies than ithomiines in the Amazon basin contrasting with the Andean concentration of ithomiine diversity. Despite this difference in broadscale diversity patterns, we also document large-scale spatial associations among phenotypically similar species within and between tribes, thereby providing new empirical evidence for Fritz Mullers historical model of mutualistic mimicry at a continental scale. Furthermore, comparative phylogenetic analyses suggest that co-mimetic species within and between tribes have converged towards similar climatic niches as a response to selection favoring co-occurrence. Our findings illustrate the strength of mutualistic interactions in shaping biodiversity patterns at continental scale and in supporting niche convergence even across millions of years of evolution. Critically, it also emphasizes the pervasive vulnerability of mimetic communities, bound by positive interactions, to disassembly induced by climate change. Significance statementMullerian mimicry is a remarkable example of convergent evolution driven by natural selection where coexisting prey species converge in their warning signal advertising their defenses to predators. Heliconiine and ithomiine butterflies found throughout Neotropical rainforests were instrumental in Fritz Mullers historical model, which provided the mechanism for such resemblance. Leveraging decades of fieldwork and museum collections, we show that species with similar color patterns present strikingly similar spatial distributions, regardless of how closely related they are. Such co-occurrence appears reinforced by the evolution of similar climatic requirements among look-alike species. Our findings emphasize the key role of mutualistic interactions in shaping large-scale patterns of biodiversity and supporting convergence in the climatic niches of species spanning across phylogenetically distant clades.

evolutionary biology↗

bioRxiv2023

Sex chromosome - autosome fusions in Heliconius butterflies

Sex chromosomes are evolutionarily labile in many animals and sometimes fuse with autosomes, creating so-called neo-sex chromosomes. Fusions between sex chromosomes and autosomes have been proposed to reduce sexual conflict and to promote adaptation and reproductive isolation among species. Recently, advances in genomics have fuelled the discovery of such fusions across the tree of life. Here, we discovered multiple fusions leading to neo-sex chromosomes in the sara/sapho clade of the classical adaptive radiation of Heliconius butterflies. Heliconius butterflies generally have 21 chromosomes with very high synteny. However, the five species in the sapho subclade show large variation in chromosome number ranging from 21 to 60. We found that the W chromosome is fused with chromosome 4 in all of them. Two sister species pairs showed subsequent fusions between the W and chromosomes 9 or 14, respectively. These sequential fusions between autosomes and sex chromosomes make Heliconius butterflies an ideal system for studying the role of neo-sex chromosomes in adaptive radiations and the degeneration of sex chromosomes over time. Our findings emphasize the capability of WGS technology to detect neo-sex chromosomes even when sex chromosomes are not explicitly assembled. Author SummaryFusions between sex chromosomes and autosomes are thought to have the potential to resolve sexual conflict and enhance local adaptation or reproductive isolation between species. Here, we discovered such fusions in Heliconius butterflies. Heliconius butterflies mostly have a very stable karyotype with 21 chromosomes and high synteny across species. However, the five species in the sapho subclade have up to 60 chromosomes, suggesting that they have undergone many chromosomal fissions. We document that in addition to the fissions, the sapho subclade also showed multiple fusions between the female-specific sex chromosome (W) and autosomes. We found a W-4 fusion shared by all five species and additional W fusions with chromosomes 9 and 14 shared by two species each. Even though in many sapho subclade species the autosomes have undergone fissions, the chromosomes fused with the W represent the full-length autosomes, as seen in other Heliconius species, suggesting that fusing to the W protected them from fissions. Our study reveals the power of short-read sequencing to discover neo-sex chromosomes and showcases Heliconius butterflies as a promising system for studying the causes and consequences of sex chromosome evolution.

evolutionary biology↗