Isobel Ronai

• Doctor of Philosophy
• Life Sciences Research Foundation Postdoctoral Fellow of HHMI at Harvard University

Ticks are a major health threat to humans and other animals, through direct damage, toxicoses, and transmission of pathogens. An estimated half a million people are treated annually in the United States of America for Lyme disease, a disease caused by the bite of a black-legged tick ( Ixodes scapularis Say) infected with the bacterial pathogen Borr...

Ticks are obligate blood-feeding parasites associated with a huge diversity of diseases globally. The hard tick Ixodes ricinus is the key vector of Lyme borreliosis and tick-borne encephalitis in Western Eurasia. Ixodes ticks have large and repetitive genomes that are not yet well characterized. Here we generate two high-quality I . ricinus genome...

A striking characteristic of the molecular techniques of genetics is that they are derived from natural occurring systems. RNA interference, for example, utilizes a mechanism that evolved in eukaryotes to destroy foreign nucleic acid. Other case studies I highlight are restriction enzymes, DNA sequencing, polymerase chain reaction, gene targeting,...

The blacklegged tick, (Ixodes scapularis Say 1821) is a vector of Borrelia burgdorferi sensu stricto (s.s.) Johnson et al. 1984, the causative bacterial agent of Lyme disease, part of a slow-moving epidemic of Lyme borreliosis spreading across the northern hemisphere. Well-known geographic differences in the vectorial capacity of these ticks are as...

The blacklegged tick, Ixodes scapularis, is a vector of Borrelia burgdorferi sensu stricto (s.s.), the causative agent of Lyme disease, part of a slow-moving epidemic of Lyme borreliosis spreading across the northern hemisphere. There are well-known geographic differences in the vectorial capacity of these ticks associated with genetic variation. D...

Insect sociality is a major evolutionary transition based on the suppression of worker reproduction in favor of the reproductive monopoly of the queen. In the honey bee ( Apis mellifera ) model organism, the development of the two female caste phenotypes, queen and worker, is triggered by differences in their larval diets. However, the mechanistic...

In the honey bee (Apis mellifera), queen and worker castes originate from identical genetic templates but develop into different phenotypes. Queens lay up to 2,000 eggs daily whereas workers are sterile in the queen’s presence. Periodically queens stop laying: during swarming, when resources are scarce in winter, and when they are confined to a cag...

The presence of DNA methylation marks within genic intervals, also called gene body methylation, is an evolutionarily‐conserved epigenetic hallmark of animal and plant methylomes. In social insects, gene body methylation is thought to contribute to behavioral plasticity, for example between foragers and nurse workers, by modulating gene expression....

Intragenic DNA methylation, also called gene body methylation, is an evolutionarily- conserved epigenetic mechanism in animals and plants. In social insects, gene body methylation is thought to contribute to behavioral plasticity, for example between foragers and nurse workers, by modulating gene expression. However, recent studies have suggested t...

In the honey bee ( Apis mellifera ), queen and worker castes originate from identical genetic templates but develop into different phenotypes. Queens lay up to 2,000 eggs daily whereas workers are sterile in the queen’s presence. Periodically queens stop laying; during swarming, when resources are scarce in winter and when they are confined to a ca...

Social insects are notable for having two female castes that exhibit extreme differences in their reproductive capacity. The molecular basis of these differences is largely unknown. Vitellogenin (Vg) is a powerful antioxidant and insulin‐signalling regulator used in oocyte development. Here we investigate how Royal Jelly (the major food of honeybee...

This book is a collection of 77 expert opinions arranged in three sections. Section 1 on "Climate" sets the scene, including predictions of future climate change, how climate change affects ecosystems, and how to model projections of the spatial distribution of ticks and tick-borne infections under different climate change scenarios. Section 2 on "...

This book is a collection of 77 expert opinions arranged in three sections. Section 1 on "Climate" sets the scene, including predictions of future climate change, how climate change affects ecosystems, and how to model projections of the spatial distribution of ticks and tick-borne infections under different climate change scenarios. Section 2 on "...

Pheromones are used by many insects to mediate social interactions. In the highly eusocial honeybee (Apis mellifera), queen mandibular pheromone (QMP) is involved in the regulation of the reproductive and other behaviour of workers. The molecular mechanisms by which QMP acts are largely unknown. Here, we investigate how genes responsible for epigen...

How does microbiota research impact our understanding of biological individuality? We summarize the interdisciplinary summer school on “Microbiota, symbiosis and individuality: conceptual and philosophical issues” (July 2019), which was supported by a European Research Council starting grant project “Immunity, DEvelopment, and the Microbiota” (IDEM...

The article below is a position statement published by the Entomological Society of America (ESA). Position statements are editorial pieces which represent the opinion of the society leadership at the time of their publishing. The development of ESA position statements is an input-driven process where the Society seeks to represent the viewpoints...

Social insects are characterised by a reproductive division of labour between queens and workers. However, in the majority of social insect species the workers are only facultatively sterile. The Australian stingless bee Tetragonula carbonaria is noteworthy as workers never lay eggs. Here we describe the reproductive anatomy of Tcarbonaria workers,...

Social insect reproduction is characterised by a division of labour. Typically, the queen is the sole reproductive female in the colony and the female workers are non-reproductive. However, in the majority of social insect species the workers are only facultatively sterile and remain capable of laying eggs under some conditions, such as when the qu...

The Asian longhorned tick (Haemaphysalis longicornis) was reported for the first time in the U.S.A. in 2017 and has now spread across 12 states. The potential of this invasive tick vector to transmit pathogens will be determined through its association to hosts, such as the white‐footed mouse (Peromyscus leucopus), which is the primary reservoir fo...

Pheromones are used by many insects to mediate social interactions. In the highly eusocial honey bee (Apis mellifera) queen mandibular pheromone is involved in the regulation of reproduction and the rate of ageing of workers. The molecular mechanisms by which queen mandibular pheromone acts remain largely unknown. Here we investigate how genes resp...

The Asian longhorned tick (Haemaphysalis longicornis) was reported for the first time in the United States of America in 2017 and has now spread across 12 states. The potential of this invasive tick vector to transmit pathogens will be determined through its association to native hosts, such as the white-footed mouse (Peromyscus leucopus) which is...

Social insects have two or more female castes that exhibit extreme differences in their reproductive capacity. The molecular basis of these differences is largely unknown. In honeybees the egg yolk protein vitellogenin (Vg), has acquired regulatory functions that go beyond reproduction, including the regulation of aging and task polyethism. Vg is s...

The majority of biomedical and biological research relies on a few molecular biology techniques. Here we show that eight key molecular biology techniques would not exist without basic biological research. We also find that the scientific reward system does not sufficiently value basic biological research into molecular mechanisms.

Hymenoptera are haplodiploid: females arise from fertilized, diploid eggs, while males arise from unfertilized, haploid eggs. The cytogenetic mechanisms underlying haplodiploidy enable remarkable phenomena including female cloning, male cloning and gynandromorphy (sex mosaics). We collected 11 newly emerged putative gynandromorph honeybees from a s...

Haplodiploid insects reproduce both sexually and asexually; haploid males arise from unfertilized eggs, while diploid females arise from fertilized eggs. Some species can also produce female offspring by thelytokous parthenogenesis. For example, queenless workers of the Cape honey bee, Apis mellifera capensis, of South Africa can produce diploid fe...

In the social insects, ovary state (the presence or absence of mature oocytes) and ovary size (the number of ovarioles) are often used as proxies for the reproductive capacity of an individual worker. Ovary size is assumed to be fixed post-eclosion whereas ovary state is demonstrably plastic post-eclosion. Here, we show that in fact ovary size decl...

In social insect colonies the presence of a queen, secreting her pheromones, is a key environmental cue for regulating the reproductive state of workers. However, until recently the proximate molecular mechanisms underlying facultative worker sterility were unidentified. Studies into worker oogenesis in the honey bee (Apis mellifera) have indicated...

Extreme reproductive skew towards particular females is a defining feature of the eusocial Hymenoptera and workers are completely sterile in at least 13 genera. The evolution of worker sterility is problematic because an individual that has decreased fertility has reduced direct fitness. Here we review the major theories that seek to explain the ev...

Worker sterility is a defining characteristic of eusociality. The existence of the sterile worker caste remains a fundamental question for evolutionary biology as it requires the existence of genes that reduce personal reproduction. Currently, little is known about the proximate mechanisms underpinning worker sterility. Studies into a mutant “anarc...

Reproductive division of labour characterises eusociality. Currently little is known about the mechanisms that underlie the 'sterility' of the worker caste, but queen pheromone plays a major role in regulating the reproductive state. Here we investigate oogenesis in the young adult honey bee worker ovary in the presence of queen pheromone and in it...