Reversing insecticide resistance with allelic-drive in Drosophila melanogaster

Nature Communications | 12 January 2022

A recurring target-site mutation identified in various pests and disease vectors alters the voltage gated sodium channel (vgsc) gene (often referred to as knockdown resistance or kdr) to confer resistance to commonly used insecticides, pyrethroids and DDT. The ubiquity of kdr mutations poses a major global threat to the continued use of insecticides as a means for vector control. In this study, we generate common kdr mutations in isogenic laboratory Drosophila strains using CRISPR/Cas9 editing.

ORAI1 limits SARS-CoV-2 infection by regulating tonic type I IFN signaling

The Journal of Immunology | 24 November 2021

ORAI1 and stromal interaction molecule 1 (STIM1) are the critical mediators of store-operated Ca2+ entry by acting as the pore subunit and an endoplasmic reticulum–resident signaling molecule, respectively. In addition to Ca2+ signaling, STIM1 is also involved in regulation of the type I IFN (IFN-I) response. To examine their potential role in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, we generated ORAI1 and STIM1 knockout human HEK293–angiotensin-converting enzyme 2 cells and checked their responses.

Neurological pathophysiology of SARS-CoV-2 and pandemic potential RNA viruses: A comparative analysis

FEBS Letters | 10 November 2021

SARS-CoV-2 has infected hundreds of millions of people with over four million dead, resulting in one of the worst global pandemics in recent history. Neurological symptoms associated with COVID-19 include anosmia, ageusia, headaches, confusion, delirium and strokes. These may manifest due to viral entry into the central nervous system (CNS) through the blood-brain barrier (BBB) by means of ill-defined mechanisms. Here we summarize the abilities of SARS-CoV-2 and other neurotropic RNA viruses, including Zika virus and Nipah virus, to cross the BBB into the CNS, highlight the role of magnetic resonance imaging (MRI) in assessing presence and severity of brain structural changes in COVID-19 patients. 

Suppressing mosquito populations with precision guided sterile males

Nature Communications | 10 September 2021

The mosquito Aedes aegypti is the principal vector for arboviruses including dengue/yellow fever, chikungunya, and Zika virus, infecting hundreds of millions of people annually. Unfortunately, traditional control methodologies are insufficient, so innovative control methods are needed. To complement existing measures, here we develop a molecular genetic control system termed precision-guided sterile insect technique (pgSIT) in Aedes aegypti.

Ecology and evolution of avian malaria: Implications of land use changes and climate change on disease dynamics

Journal of the Indian Institute of Science | June 3, 2021

Malaria is the deadliest of all mosquito-borne diseases. Thousands of malaria parasite species exploit squamate reptiles, birds, and mammals as vertebrate hosts as well as dipteran vectors. Among these, avian malaria and related parasites have revealed an extensive genetic diversity as well as phenotypic diversity with varying virulence, host range, distribution−offering an amenable experimental system which has played a key role in understanding the ecology and evolution of human malaria parasites.

Plasmodium Chitinases: Revisiting a target of transmission‐blockade against malaria

Protein Science | May 2, 2021

Malaria is a life‐threatening disease caused by one of the five species of Plasmodium, among which Plasmodium falciparum cause the deadliest form of the disease. Plasmodium species are dependent on a vertebrate host and a blood‐sucking insect vector to complete their life cycle. Plasmodium chitinases belonging to the GH18 family are secreted inside the mosquito midgut, during the ookinete stage of the parasite. Chitinases mediate the penetration of parasite through the peritrophic membrane, facilitating access to the gut epithelial layer. In this review, we describe Plasmodium chitinases with special emphasis on chitinases from P. falciparum and P. vivax, the representative examples of the short and long forms of this protein…

Parasite and vector of the month – Anopheles stephensi

Trends in Parasitology | April 14, 2021

Anopheles stephensi originated in Southeast Asia and the Arabian Peninsula. It has recently emerged as an efficient and invasive urban malaria vector. There are three known forms, ‘type’, ‘intermediate’, and ‘mysorensis’, of which the type and intermediate forms are efficient vectors in both rural and urban environments…

Antagonistic roles for Ataxin-2 structured and disordered domains in RNP condensation

eLife | March 10, 2021

Ataxin-2 (Atx2) is a translational control molecule mutated in spinocerebellar ataxia type II and amyotrophic lateral sclerosis. While intrinsically disordered domains (IDRs) of Atx2 facilitate mRNP condensation into granules, how IDRs work with structured domains to enable positive and negative regulation of target mRNAs remains unclear. Using the Targets of RNA-Binding Proteins Identified by Editing technology, we identified an extensive data set of Atx2-target mRNAs in the Drosophila brain and S2 cells…

Hidden genomic features of an invasive malaria vector, Anopheles stephensi, revealed by a chromosome-level genome assembly

BMC Biology | February 10, 2021

The mosquito Anopheles stephensi is a vector of urban malaria in Asia that recently invaded Africa. Studying the genetic basis of vectorial capacity and engineering genetic interventions are both impeded by limitations of a vector’s genome assembly. The existing assemblies of An. stephensi are draft-quality and contain thousands of sequence gaps, potentially missing genetic elements important for its biology and evolution.

The effect of habitat quality on the blood parasite assemblage in understorey avian insectivores in the Eastern Himalaya, India

Ibis | January 18, 2021

The anthropogenic alteration of natural habitats can modify interactions between various biotic and abiotic factors. The prevalence of avian blood parasites in free‐living host species in the tropics has shown contrasting patterns in altered landscapes. Here, we investigate these potential associations between understorey insectivorous bird species of the Eastern Himalayas and avian haemosporidians in primary and selectively logged forests. 

A near-chromosome level genome assembly of Anopheles stephensi

Frontiers in Genetics | November 16, 2020

Malaria remains a major healthcare risk to growing economies like India, and a chromosome-level reference genome of Anopheles stephensi is critical for successful vector management and understanding of vector evolution using comparative genomics. We report chromosome-level assemblies of an Indian strain, STE2, and a Pakistani strain SDA-500 by combining draft genomes of the two strains using a homology-based iterative approach. 

Efficient population modification gene-drive rescue system in the malaria mosquito Anopheles stephensi

Nature Communications | November 03, 2020

Cas9/gRNA-mediated gene-drive systems have advanced development of genetic technologies for controlling vector-borne pathogen transmission. These technologies include population suppression approaches, genetic analogs of insecticidal techniques that reduce the number of insect vectors, and population modification (replacement/alteration) approaches, which interfere with competence to transmit pathogens. Here, we develop a recoded gene-drive rescue system for population modification of the malaria vector, Anopheles stephensi

Genetic drift and bottleneck do not influence diversity in Toll‐like receptor genes at a small spatial scale in a Himalayan passerine

Ecology and Evolution | October 15, 2020

Genetic diversity is important for long‐term viability of a population. Low genetic diversity reduces persistence and survival of populations and increases susceptibility to diseases. Comparisons of the neutral markers with functional loci such as immune genes [Toll‐like receptors; TLR] can provide useful insights into evolutionary potential of a species and how the diversity of pathogens and selection pressures on their hosts are directly linked to their environment.

Heinrich Reichert

The Company of Biologists Ltd

Heinrich Reichert, Professor Emeritus at the University of Basel,
Switzerland, passed away on the 13th of June 2019 after a prolonged
illness. Heinrich described himself as ‘a hedonist when it came to
science’ because he said it gave him great pleasure. It was this quality
that made working with Heinrich thrilling and deeply fulfilling.[…]

Neurotransmitter identity: A question of lineage

elifesciences | May 7, 2019

The nervous system develops from a small number of neural stems cells that generate all the different types of neurons found in an organism. First, a process of spatial patterning imparts unique molecular identities to individual neural stem cells, making them distinct from one another […]

Efficient allelic drive in Drosophila

Nature Communications | April 09, 2019

Gene-drive systems developed in several organisms result in super-Mendelian inheritance of transgenic insertions. Here, we generalize this “active genetic” approach to preferentially transmit allelic variants (allelic-drive) resulting from only a single or a few nucleotide alterations.[…]