Current opinion in insect science最新文献

Odors serve as important cues for many behaviors in mosquitoes, including host-seeking, foraging, and oviposition. They are detected by olfactory receptor neurons present on the sensory organs, whose axons take this signal to the antennal lobe, the first olfactory processing center in the insect brain. We review the organization and the functioning of the antennal lobe in mosquitoes, focusing on two populations of interneurons present there: the local neurons (LNs) and the projection neurons (PNs). LNs enable information processing in the antennal lobe by providing lateral inhibition and excitation. PNs carry the processed output to downstream neurons in the lateral horn and the mushroom body. We compare the ideas of labeled lines and combinatorial codes, and argue that the PN population encodes odors combinatorially. Throughout this review, we discuss the observations from Aedes, Anopheles, and Culex mosquitoes in the context of previous findings from Drosophila and other insects.

Currently, a wealth of genomic data is now accessible for numerous insect natural enemies, serving as valuable resources that deepen our understanding of the genetic basis of biocontrol traits in these organisms. We summarize the current state of genome sequencing and highlight candidate genes related to biocontrol traits that hold promise for genetic improvement. We also review the recent population genomic studies in biological control and the discovery of potential insecticidal genes in parasitoid wasps. Collectively, current genomic works have shown the powerful ability to identify candidate genes responsible for desirable traits or promising effectors. However, further functional study is necessary to gain a mechanistic understanding of these genes, and future efforts are also needed to develop suitable approaches to translate genomic insights into field applications.

Female germline stem cells (fGSCs) are essential for generating mature oocytes. In general, self-renewal and differentiation of fGSCs into germ cells are regulated by niche signals from neighboring niche cells. In addition, fGSCs and their niche cells are greatly influenced by physiological and environmental factors, especially nutritional status. To clarify molecular mechanisms involved in regulating fGSC proliferation and maintenance, the fruit fly Drosophila melanogaster has served as an excellent genetic model organism. In recent years, along with sophisticated genetic tools for D. melanogaster, large-scale transcriptome, proteome, and metabolome analyses have provided new insights into D. melanogaster fGSC biology. These large-scale analyses have identified new markers and regulators for D. melanogaster fGSCs, including Netrin-A, Helical factor, eggplant, Gr43a, and genes controlling the polyol pathway, some of which are involved in nutrient-responsive control of fGSC behavior.

Insects exhibit remarkable adaptability to a wide range of environmental stressors, including temperature fluctuations, pathogens, and changes in diet. This adaptability is often driven by epigenetic processes, which regulate gene expression without altering the underlying DNA sequence. This review provides a comprehensive overview of these epigenetic processes in insect adaptation, highlighting their impact on development, behaviour, and stress resilience. Understanding these mechanisms is essential for pest management and conservation efforts, offering insights into the rapid adaptive capacity of insects. By examining recent studies on epigenetics in insects, we aim to elucidate the molecular underpinnings of their adaptation and suggest future research directions in this evolving field.

Like other eukaryotes, insect genomes contain a large portion of repetitive sequences, particularly transposable elements (TEs) and satellite DNAs (satDNAs). This review highlights key studies on repetitive DNAs and examines their structural, functional, and evolutionary impact in insect genomes. Repetitive sequences promote genetic diversification through mutations and large-scale rearrangements, playing a crucial role in shaping genomic architecture, aiding organismal adaptation and driving speciation. We also explore the influence of repeats in genome size variation and species incompatibilities, along with their contribution to adaptive phenotypes and gene regulation. Studying repetitive DNA in insects not only provides insights into basic genomic features but also offers valuable information for conservation strategies, pest control, and advancements in genetics, ecology, and evolutionary biology.

Sexually dimorphic behaviors are fundamental to the biology of many species, including fruit flies and humans. These behaviors are regulated primarily by sex-specific neural circuits or the sex-specific modulation of shared neuronal substrates. In fruit flies, GABAergic neurotransmission plays a critical role in governing sexually dimorphic behaviors such as courtship, copulation, and aggression. This review explores the intricate roles of GABAergic neurons in these behaviors, and focuses on how sex-specific differences in GABAergic circuits contribute to their modulation and execution. By examining these mechanisms in Drosophila, we reveal broader implications for understanding sexual dimorphism in more complex organisms.

Insects represent the most diverse group of animals in the world. While the olfactory systems of different species share general principles of organization, they also exhibit a wide range of structural and functional diversity. Scientists have gained tremendous insight into olfactory neural development and function, notably in Drosophila, but also in other insect species (see reviews in [1-3]). In the last few years, new evidence has steadily mounted, e.g. the stoichiometry of odorant receptor and co-receptor (OR-Orco) complex. This review aims to highlight the recent progress on four aspects: (1) the structure and function of the OR-Orco complex, (2) chemosensory gene co-expression, (3) diverse neural developmental processes, and (4) the role of genes and neurons in olfactory development and olfactory-mediated behavior.