Biology subjects

Hashmi, Y.

Publications and source records attributed to Hashmi, Y..

5 recordsLinked to original sources

bioRxiv2026

A nuclear targeting approach enables efficient transgenesis in the milkweed bug Oncopeltus fasciatus

Insects show extreme diversity and have long intrigued biologists. Recent technological advancements, such as gene editing and transgenesis, should in principle enable the use of almost any insect species for biological research. However, in practice, species-specific challenges remain and conditions must be optimized carefully. Here, using the milkweed bug Oncopeltus fasciatus, we first generate a useful eye- and body-color mutant strain by using CRISPR/Cas9-mediated genome editing. Then we use this strain to develop an efficient piggyBac-mediated transgenesis system using a nuclear targeting approach. We show that incorporating 1x and 3x nuclear localization signals (NLS) into piggyBac mRNA substantially enhances overall transformation efficiency in O. fasciatus. Taking advantage of both the useful mutant strain and the efficient transgenesis system, we successfully integrated multiple expression cassettes ranging from 1.8 to 7.2 kb, including attP strains for phiC31-mediated site-specific integration and histone-labelled strains for live fluorescence imaging. We further provide evidence that the Q system, a binary expression system, is functional in this species, paving the way for future sophisticated genetic manipulations including functional assays for cis-regulatory elements. Together, our results not only expand the genetic toolkit of O. fasciatus as a comparative model insect, but also provide a practical framework for developing efficient transgenesis in other non-traditional model organisms.

developmental biology↗

bioRxiv2026

Husbandry and Maintenance of Carausius morosus Laboratory Populations

Carausius morosus, the Indian stick insect, is a slender twig-like insect endemic to India. Though widely introduced through captivity around the world and commonly used in laboratories or kept as a household pet, standardized animal husbandry laboratory protocols are lacking. Here we report detailed laboratory culture conditions for C. morosus. We maintain stocks at 23 {degrees}C, 70% relative humidity, and a 12:12 hour light-dark photoperiod. This culture has been successfully sustained under these conditions for over two years, with standardized protocols in place for dietary and cage setup conditions. We also report methods for egg and hatchling care to support ongoing experiments with C. morosus. These standardized methods improve reproducibility and accessibility, enabling the broader use of C. morosus as a laboratory model system for developmental, behavioral, and physiological studies. SummaryThis paper outlines detailed protocols for maintaining a Carausius morosus laboratory colony, including key procedures for animal husbandry, egg and hatchling care, and an overview of the species lifespan and biological characteristics.

developmental biology↗

bioRxiv2025

A family of lethal exotoxins defined by cell entry via the Attractin receptor

Although bacterial genomes encode numerous potential toxins, it is unclear how evolution drives the specificity of these important virulence factors. Using an insect CRISPR screen, we identified the transmembrane protein Attractin (ATRN) as the receptor for Nigritoxin (Ntx), a Vibrio toxin that causes seasonal shrimp pandemics. We found that Ntxs effector "warhead" inhibits translation via a previously uncharacterized mechanism. Moreover, we show that two related toxins require ATRN for entry but possess unrelated effector domains. One has a Rho-GTPase AMPylation function and the other an actin-targeting/proteolysis function. Our findings reveal the mechanism of Ntx entry and toxicity and show that the ATRN-targeting domain can deliver disparate effector domains, strongly indicating that this class of exotoxins can evolve as modular proteins using a common entry domain.

microbiology↗

bioRxiv2025

Multi-omic mapping of Drosophila protein secretomes reveals tissue-specific origins and inter-organ trafficking

Secreted proteins regulate many aspects of animal biology and are attractive targets for biomarkers and therapeutics. However, comprehensively identifying the "secretome", along with their tissues of origin, remains extremely challenging. To address this, we employed multiple omics methods to define a tissue-secretome map of 535 blood plasma proteins derived from specific cell-types and organs in Drosophila melanogaster. This map was enabled by methodological improvements including a collection of transgenic flies to label endogenous secreted proteins in 10 major tissue types, large-scale blood isolation, whole animal snRNA-seq, and a collection of 40 knock-in strains. Using this map, we discover surprising findings about circulating proteins: most originate from specific tissues including unusual sources (e.g. glia), many are uncharacterized, and some are shed ectodomains of transmembrane proteins. In addition, in vivo experiments revealed circulating proteins with remarkably tissue-specific expression, as well as proteins that are deposited in a different tissue from where they are synthesized, suggesting potential inter-organ functions. Our secretome map will serve as a resource to investigate blood protein function, discover novel tissue-tissue communication signals, and mine for homologues of human biomarkers.

genomics↗

bioRxiv2020

Regulation of blood cell transdifferentiation by oxygen sensing neurons in Drosophila

Transdifferentiation generates specialized cell types independent of stem or progenitor cells. Despite the unique process, it remains poorly understood how transdifferentiation is regulated in vivo. Here we reveal a mechanism of environmental control of blood cell transdifferentiation in a Drosophila model of hematopoiesis. Functional lineage tracing provides evidence for transdifferentiation from macrophage-like plasmatocytes to crystal cells that execute melanization. Interestingly, this transdifferentiation is promoted by neuronal activity of a specific subset of sensory neurons, in the caudal sensory cones of the larva. Crystal cells develop from plasmatocyte clusters surrounding the sensory cones, triggered by environmental conditions: oxygen sensing, and the atypical guanylyl cyclase Gyc88E specifically expressed in the sensory cone neurons, drive plasmatocyte-to-crystal cell transdifferentiation. Our findings reveal an unexpected functional and molecular link of environment-monitoring sensory neurons that govern blood cell transdifferentiation in vivo, suggesting similar principles in vertebrate systems where environmental sensors and blood cell populations coincide. HighlightsO_LIFunctional lineage tracing reveals in vivo transdifferentiation in a Drosophila model of hematopoiesis C_LIO_LIActive sensory neurons of the caudal sensory cones promote blood cell transdifferentiation in the Drosophila larva C_LIO_LIEnvironmental oxygen sensing and atypical guanylyl cyclase activity in sensory cone neurons drive blood cell transdifferentiation C_LI

developmental biology↗