A Novel Expression Domain of extradenticle Underlies the Evolutionary Developmental Origin of the Chelicerate Patella.

Neofunctionalization of duplicated gene copies is thought to be an important process underlying the origin of evolutionary novelty and provides an elegant mechanism for the origin of new phenotypic traits. One putative case where a new gene copy has been linked to a novel morphological trait is the origin of the arachnid patella, a taxonomically restricted leg segment. In spiders, the origin of this segment has been linked to the origin of the paralog dachshund-2, suggesting that a new gene facilitated the expression of a new trait.

Validation of heat-inducible HSP70 and tick-specific 3xP3 promoters in ISE6 cells.

is an important vector of many pathogens, including the causative agent of Lyme disease. The gene function studies in and other ticks are hampered by the lack of genetic tools, including an inducible promoter for temporal control over transgene-encoding protein or double-stranded RNA. We characterized an intergenic sequence upstream of a heat shock protein 70 (HSP70) gene that can drive luciferase and mCherry expression in the cell line ISE6 (IsHSP70).

Gene editing in agricultural, health, and veterinary pest arthropods: recent advances.

Pest arthropods cause significant crop damage or are vectors of pathogens for both plants and animals. The current standard of pest management prevents against crop losses and protects human and animal health, but shortcomings exist, such as insecticide resistance and environmental damage to nontarget organisms. New management methods are therefore needed.

A novel expression domain of underlies the evolutionary developmental origin of the chelicerate patella.

Neofunctionalization of duplicated gene copies is thought to be an important process underlying the origin of evolutionary novelty and provides an elegant mechanism for the origin of new phenotypic traits. One putative case where a new gene copy has been linked to a novel morphological trait is the origin of the arachnid patella, a taxonomically restricted leg segment. In spiders, the origin of this segment has been linked to the origin of the paralog , suggesting that a new gene facilitated the expression of a new trait.

Arthropod promoters for genetic control of disease vectors.

Vector-borne diseases (VBDs) impose devastating effects on human health and a heavy financial burden. Malaria, Lyme disease, and dengue fever are just a few examples of VBDs that cause severe illnesses. The current strategies to control VBDs consist mainly of environmental modification and chemical use, and to a small extent, genetic approaches.

Validation of a heat-inducible HSP70 promoter and developing a tick-specific 3xP3 promoter sequence in ISE6 cells.

is an important vector of many pathogens, including the causative agent of Lyme disease, tick-borne encephalitis, and anaplasmosis. The study of gene function in and other ticks has been hampered by the lack of genetic tools, such as an inducible promoter to permit temporal control over transgenes encoding protein or double-stranded RNA expression. Studies of vector-pathogen relationships would also benefit from the capability to activate anti-pathogen genes at different times during pathogen infection and dissemination.

The highly improved genome of with X and Y pseudochromosomes.

, the black-legged tick, is the principal vector of the Lyme disease spirochete, , and is responsible for most of the ∼470,000 estimated Lyme disease cases annually in the USA. can transmit six additional pathogens of human health significance. Because of its medical importance, was the first tick genome to be sequenced and annotated.

Trypsin, the Major Proteolytic Enzyme for Blood Digestion in the Mosquito Midgut.

When a female mosquito takes a blood meal, proteolytic activity surges in the midgut. Trypsin-like serine proteases are the major endoproteolytic enzyme induced by feeding in mosquitoes. The mosquito midgut lacks trypsin activity before the blood meal, but in most anautogenous mosquitoes, trypsin activity increases continuously up to 30 h after feeding and subsequently returns to baseline levels by 60 h.

Analyzing Blood Digestion: Estimation of Active Trypsin Levels in the Mosquito Midgut.

The α-benzoyl-dl-arginine 4-nitroanilide hydrochloride (BApNA) assay is widely used to quantify trypsin in mosquito midguts and is highly sensitive. BApNA is a chromogenic substrate for proteolytic enzymes such as trypsin and amidase. Hydrolysis of BApNA at the bond between the arginine and the p-nitroaniline moieties releases the chromophore p-nitroaniline, which is detected by colorimetric analysis.

Embryo Injection Technique for Gene Editing in the Black-Legged Tick, Ixodes scapularis.

Ticks can transmit various viral, bacterial, and protozoan pathogens and are therefore considered vectors of medical and veterinary importance. Despite the growing burden of tick-borne diseases, research on ticks has lagged behind insect disease vectors due to challenges in applying genetic transformation tools for functional studies to the unique biology of ticks. Genetic interventions have been gaining attention to reduce mosquito-borne diseases.

Cas9-mediated gene editing in the black-legged tick, , by embryo injection and ReMOT Control.

Despite their capacity to acquire and pass on an array of debilitating pathogens, research on ticks has lagged behind other arthropod vectors, such as mosquitoes, largely because of challenges in applying available genetic and molecular tools. CRISPR-Cas9 is transforming non-model organism research; however, successful gene editing has not yet been reported in ticks. Technical challenges for injecting tick embryos to attempt gene editing have further slowed research progress.

Ecology of Ticks and Associated Pathogens in the Western United States.

Lyme disease is the most important vector-borne disease in the United States and is increasing in incidence and geographic range. In the Pacific west, the western black-legged tick, Cooley and Kohls, 1943 is an important vector of the causative agent of Lyme disease, the spirochete, . life cycle is expected to be more than a year long, and all three stages (larva, nymph, and adult) overlap in spring.

RNAi by Soaking Pupae in dsRNA.

RNA-interference (RNAi) is a standard technique for functional genomics in adult mosquitoes. However, RNAi in immature, aquatic mosquito stages has been challenging. Several studies have shown successful larval RNAi, usually in combination with a carrier molecule.

Characterization of Odorant Receptor 8, an Abundant Component of the Mouthpart Chemosensory Transcriptome.

Several mosquito species within the genus are vectors for human malaria, and the spread of this disease is driven by the propensity of certain species to feed preferentially on humans. The study of olfaction in mosquitoes is important to understand dynamics of host-seeking and host-selection; however, the majority of these studies focus on or , both vectors of malaria in Sub-Saharan Africa. Other malaria vectors may recognize different chemical cues from potential hosts; therefore, in this study, we investigated , the south Asian malaria mosquito.

Genetic Manipulation of Ticks: A Paradigm Shift in Tick and Tick-Borne Diseases Research.

Ticks are obligate hematophagous arthropods that are distributed worldwide and are one of the most important vectors of pathogens affecting humans and animals. Despite the growing burden of tick-borne diseases, research on ticks has lagged behind other arthropod vectors, such as mosquitoes. This is largely because of challenges in applying functional genomics and genetic tools to the idiosyncrasies unique to tick biology, particularly techniques for stable genetic transformations.

The sugar substitute erythritol shortens the lifespan of Aedes aegypti potentially by N-linked protein glycosylation.

Adult male and female mosquitoes consume sugar as floral and extrafloral nectar. Earlier work demonstrated that mosquito populations and their vector potential are dependent upon the availability of sugar sources. Thus, a novel method of vector control may involve targeting sugar-feeding mosquitoes.

Blood Digestion by Trypsin-Like Serine Proteases in the Replete Lyme Disease Vector Tick, .

is the major vector of Lyme disease in the Eastern United States. Each active life stage (larva, nymph, and adult) takes a blood meal either for developing and molting to the next stage (larvae and nymphs) or for oviposition (adult females). This protein-rich blood meal is the only food taken by ticks and therefore efficient blood digestion is critical for survival.

Dynamics of Insulin Signaling in the Black-Legged Tick, .

Insulin-like peptides (ILPs) have been identified in several invertebrates, particularly insects, and work on these ILPs has revealed many roles including regulation of energy homeostasis, growth, development, and lifespan to name a few. However, information on arthropod ILPs outside of insects is sparse. Studies of Ixodid tick ILPs are particularly scarce, despite their importance as vectors of infectious agents, most notably Lyme disease.

Insulin-Like Peptide Signaling in Mosquitoes: The Road Behind and the Road Ahead.

Insulin signaling is a conserved pathway in all metazoans. This pathway contributed toward primordial metazoans responding to a greater diversity of environmental signals by modulating nutritional storage, reproduction, and longevity. Most of our knowledge of insulin signaling in insects comes from the vinegar fly, , where it has been extensively studied and shown to control several physiological processes.

Non-model organism research in the changing genomic landscape.

It is estimated that the planet earth is host to approximately ten million species of plants and animals with only approximately 1.5 million documented in the Catalogue of Life. However, our knowledge of biochemical, molecular, genetics, and cellular processes comes from the studies of fewer than a dozen organisms.

Nutritional Quality during Development Alters Insulin-Like Peptides' Expression and Physiology of the Adult Yellow Fever Mosquito, .

Mosquitoes have distinct developmental and adult life history, and the vectorial capacity of females has been shown to be affected by the larval nutritional environment. However, little is known about the effect of developmental nutrition on insulin-signaling and nutrient storage. In this study, we used , the yellow fever mosquito, to determine whether larval nutrition affects insulin gene expression.

Insulin receptor knockdown blocks filarial parasite development and alters egg production in the southern house mosquito, Culex quinquefasciatus.

Lymphatic filariasis, commonly known as elephantiasis, is a painful and profoundly disfiguring disease. Wuchreria bancrofti (Wb) is responsible for >90% of infections and the remainder are caused by Brugia spp. Mosquitoes of the genera Culex (in urban and semi-urban areas), Anopheles (in rural areas of Africa and elsewhere), and Aedes (in Pacific islands) are the major vectors of W.

Rearing Ixodes scapularis, the Black-legged Tick: Feeding Immature Stages on Mice.

Ixodes scapularis, the vector of Lyme disease, is one of the most important disease vectors in the eastern and Midwestern United States. This species is a three host tick that requires a blood meal from a vertebrate host for each development stage, and the adult females require a blood meal for reproduction. Larval ticks attach to their host for 3 - 5 days for feeding and drop off the host when fully engorged.