Biology subjects

Antoshechkin, I. A.

Publications and source records attributed to Antoshechkin, I. A..

3 recordsLinked to original sources

bioRxiv2023

The genomic and cellular basis of biosynthetic innovation in rove beetles

How evolution at the cellular level potentiates change at the macroevolutionary level is a major question in evolutionary biology. With >66,000 described species, rove beetles (Staphylinidae) comprise the largest metazoan family. Their exceptional radiation has been coupled to pervasive biosynthetic innovation whereby numerous lineages bear defensive glands with diverse chemistries. Here, we combine comparative genomic and single-cell transcriptomic data from across the largest rove beetle clade, Aleocharinae. We retrace the functional evolution of two novel secretory cell types that together comprise the tergal gland--a putative catalyst behind Aleocharinaes megadiversity. We identify key genomic contingencies that were critical to the assembly of each cell type and their organ-level partnership in manufacturing the beetles defensive secretion. This process hinged on evolving a mechanism for regulated production of noxious benzoquinones that appears convergent with plant toxin release systems, and synthesis of an effective benzoquinone solvent that weaponized the total secretion. We show that this cooperative biosynthetic system arose at the Jurassic-Cretaceous boundary, and that following its establishment, both cell types underwent [~]150 million years of stasis, their chemistry and core molecular architecture maintained almost clade-wide as Aleocharinae radiated globally into tens of thousands of lineages. Despite this deep conservation, we show that the two cell types have acted as substrates for the emergence of adaptive, biochemical novelties--most dramatically in symbiotic lineages that have infiltrated social insect colonies and produce host behavior-manipulating secretions. Our findings uncover genomic and cell type evolutionary processes underlying the origin, functional conservation and evolvability of a chemical innovation in beetles.

evolutionary biology↗

bioRxiv2022

CRISPR Mediated Transactivation in the Human Disease Vector Aedes aegypti

As a major insect vector of multiple arboviruses, Aedes aegypti poses a significant global health and economic burden. A number of genetic engineering tools have been exploited to understand its biology with the goal of reducing its impact. For example, current tools have focused on knocking-down RNA transcripts, inducing loss-of-function mutations or expressing exogenous DNA. However, methods for transactivating endogenous genes have not been developed. To fill this void, here we developed a CRISPR activation (CRISPRa) system in Ae. aegypti to transactivate target gene expression. Gene expression is activated through pairing a catalytically-inactive ( dead) Cas9 (dCas9) with a highly-active tripartite activator, VP64-p65-Rta (VPR) and synthetic guide RNA (sgRNA) complementary to a user defined target-gene promoter region. As a proof of concept, we demonstrate that engineered Ae. aegypti mosquitoes harboring a binary CRISPRa system can be used to effectively overexpress two developmental genes, even-skipped (eve) and hedgehog (hh), resulting in observable morphological phenotypes. We also used this system to overexpress the positive transcriptional regulator of the Toll immune pathway known as AaRel1, which resulted in a significant suppression of dengue virus serotype 2 (DENV2). This system provides a versatile tool for research pathways not previously possible in Ae. aegypti, such as programmed overexpression of endogenous genes, and may lead to the development of innovative vector control tools.

bioengineering↗

bioRxiv2020

Molecular evolutionary trends and biosynthesis pathways in the Oribatida revealed by the genome of Archegozetes longisetosus

Oribatid mites are a specious order of microarthropods within the subphylum Chelicerata, compromising about 11,000 described species. They are ubiquitously distributed across different microhabitats in all terrestrial ecosystems around the world and were among the first animals colonizing terrestrial habitats as decomposers and scavengers. Despite their species richness and ecological importance genomic resources are lacking for oribatids. Here, we present a 190-Mb genome assembly of the clonal, all-female oribatid mite species Archegozetes longisetosus Aoki, a model species used by numerous laboratories for the past 30 years. Comparative genomic and transcriptional analyses revealed patterns of reduced body segmentation and loss of segmental identity gene abd-A within Acariformes, and unexpected expression of key eye development genes in these eyeless mites across developmental stages. Consistent with their soil dwelling lifestyle, investigation of the sensory genes revealed a species-specific expansion of gustatory receptors, the largest chemoreceptor family in the genome used in olfaction, and evidence of horizontally transferred enzymes used in cell wall degradation of plant and fungal matter, both components of the A. longisetosus diet. Oribatid mites are also noted for their biosynthesis capacities and biochemical diversity. Using biochemical and genomic data, we were able to delineate the backbone biosynthesis of monoterpenes, an important class of compounds found in the major exocrine gland system of Oribatida - the oil glands. Given the mites strength as an experimental model, the new high-quality resources provided here will serve as the foundation for molecular research in Oribatida and will enable a broader understanding of chelicerate evolution.

zoology↗