Biology subjects

Partosh, T.

Publications and source records attributed to Partosh, T..

4 recordsLinked to original sources

bioRxiv2025

An OpIE2-DsRed marker disrupts female blood-feeding and shortens lifespan in the malaria vector Anopheles gambiae.

Anopheles gambiae is one of the principal vectors of human malaria. Over the past two decades, transgenic mosquito strains have been essential tools for studying mosquito biology and developing genetic control strategies such as gene drives. Mosquito transformants are typically identified using fluorescent markers, which are assumed to be phenotypically neutral. While generating CRISPR-based gene drive strains carrying an OpIE2-DsRed marker we unexpectedly found that transgenic females were unable to blood-feed and were consequently sterile, whereas males initially appeared normal and fertile. Given the potential utility of dominant, female-specific sterility for mosquito control, we established additional strains controlling for transgene content and integration site, confirming that the OpIE2-DsRed cassette caused the defect. Behavioral assays showed that females exhibited normal attraction to a membrane feeder but failed to initiate blood-feeding, performing repeated cycles of probing and proboscis grooming in rapid succession before ultimately leaving the feeder unfed. Microscopy showed that both sexes possessed a distally curved proboscis, providing a morphological explanation for the blood-feeding defect of females and the reduced male lifespan. A second promoter variant (OpIE2b), differing in flanking sequences at the IE-2 junction, drove strong marker expression without impairing blood-feeding or longevity. These findings demonstrate that minor differences in promoter architecture can produce major, unexpected phenotypic effects. OpIE2b provides a robust, phenotypically neutral marker for An. gambiae research, while OpIE2a highlights the need for rigorous validation of transgenic components intended for research and applied releases.

genetics↗

bioRxiv2025

CRISPR/Cas9-mediated mutagenesis of the white-eye gene in the tephritid pest Bactrocera zonata

Bactrocera zonata is a highly invasive agricultural pest that causes extensive damage to fruit crops. The Sterile Insect Technique (SIT), a species-specific and environmentally friendly pest control method, depends on the availability of Genetic Sexing Strains (GSSs) to enable efficient mass production of males for sterile release. However, no GSS currently exists for B. zonata limiting SIT applications targeting this important invasive pest. Here, we report two key advancements toward GSS development in this species. First, we present a high-quality, chromosome-level genome assembly from male B. zonata, identifying two scaffolds derived from the Y chromosome, which represent potential targets for future male-specific genetic engineering. Second, we demonstrate the feasibility of CRISPR/Cas9 genome editing in B. zonata by generating stable, homozygous white-eye mutants through targeted disruption of the conserved white-eye gene. This visible, recessive phenotype serves as a proof-of-concept for developing selectable markers in this species. Together, these results provide foundational genomic and genetic tools to support the development of GSSs in B. zonata, advancing the potential for sustainable, genetics-based pest control strategies.

bioengineering↗

bioRxiv2023

CRISPR-Based Genome Editing in Harmonia Axyridis

Harmonia axyridis (Pallas), commonly known as the Asian lady beetle, is a native insect species of Asia that has been intentionally introduced to various regions for biocontrol purposes. However, its widespread presence beyond its original release sites suggests a high degree of invasiveness. Previous studies have employed double-stranded RNA techniques to investigate the functional genomics of this species. In this study, we utilized the CRISPR-Cas9 approach to achieve precise genome editing in H. axyridis. Specifically, we targeted two distinct genes known to exhibit visible phenotypic effects. While the knockout of the laccase2 gene resulted in an early-detectable phenotype but also in lethality, we successfully established a viable and genetically stable mutant colony by disrupting the scarlet gene. Our findings contribute to the expanding knowledge of genetic manipulation in H. axyridis and provide insights into its potential for future research and practical applications for biocontrol and invasive species management.

genomics↗

bioRxiv2022

Rapid and sensitive on-site genetic diagnostics of pest fruit flies using CRISPR-Cas12a

Bactrocera zonata, a major fruit pest species, is gradually spreading west from its native habitat in East Asia. In recent years it has become a major threat to the Mediterranean area, with the potential of invading Europe, the Americas, and Australia. To prevent its spreading, monitoring efforts in plantation sites and border controls are carried out. Despite these efforts, and due to morphological similarities between B. zonata and other pests in relevant developmental stages, the monitoring process is challenging, time-consuming, and requires external assistance from professional labs. CRISPR-Cas12a genetic diagnostics has been rapidly developing in recent years and provides an efficient tool for the genetic identification of pathogens, viruses, and other genetic targets. Here we design a CRISPR-Cas12a detection assay that differentially detects two major pest species, B. zonata and Ceratitis capitata. Our easy-to-use and affordable assay employs a simple DNA extraction technique together with isothermal amplification, and Cas12a-based detection. We demonstrate the specificity and high sensitivity of this method, and its relevance for on-site applications. This method is highly modular, and the presented target design method can be applied to a wide array of pests. Key MassageO_LIDistinguishing different pest fruit flies on-site is crucial for prevention of global spreading but can be difficult C_LIO_LIWe present a genetic identification assay for rapid, on-site detection of pest using CRISPR-Cas12a C_LIO_LIThe method is affordable, quick and easy-to-use, and can be applied in border controls or on-site C_LIO_LIThe design process can be easily tailored for any pest, and can greatly benefit developing countries C_LI

synthetic biology↗