Biology subjects

Jiang, N.-J.

Publications and source records attributed to Jiang, N.-J..

3 recordsLinked to original sources

bioRxiv2025

Nematode infections induce distinct chemical signatures and provoke aggression in ants

Maintaining group integrity by excluding outsiders and pathogens is a fundamental requirement and challenge of social living. In social insects, these defences rely heavily on chemical communication, with cuticular hydrocarbons (CHCs) mediating both nestmate recognition and infection-related social responses. In ants, CHCs are stored and homogenised in the pharyngeal gland, contributing to the formation of a shared colony odour that enables nestmate recognition. We investigated the behavioural and chemical responses of the clonal raider ant Ooceraea biroi to infections by the nematode Diploscapter sp., which specifically infects the pharyngeal gland. Using behavioural and chemical analyses, we show that: 1) infected ants elicit increased aggression from uninfected nestmates and non-nestmates, consistent with a social immune defence that limits parasite entry in colonies, 2) aggression is likely driven by infection-specific changes in CHC profiles, and 3) infections do not compromise nestmate recognition, which acts through distinct CHCs. Thus, while many parasitic nematodes can evade host immune recognition, Diploscapter fails to evade the social recognition system of its host. The efficient detection and exclusion of infected individuals likely reduce parasite introduction and transmission both within and between colonies.

animal behavior and cognition↗

bioRxiv2024

Temperature-mediated dynamics: unraveling the impact of temperature on cuticular hydrocarbon profiles, mating behavior, and life history traits in three Drosophila species

In a world grappling with climate change, understanding the enduring impact of changes in temperature on insect adult traits is crucial. Here, we explored the intricate dynamics of exposure to different temperatures in three Drosophila species: Drosophila ezoana originating in Arctic regions, D. novamexicana in arid, hot environments, and in the cosmopolitan species D. virilis. Rearing these flies at 15, 20, 25, and 30{degrees}C revealed striking variations in their cuticular hydrocarbon (CHC) profiles, known to mediate mate recognition and prevent water loss in insects. The cold-adapted D. ezoana consistently exhibited reduced CHC levels with increasing temperatures, while the warm-adapted D. novamexicana and the cosmopolitan D. virilis displayed more nuanced responses. Additionally, we observed a significant influence of rearing temperature on the mating behavior of these flies, where those reared at the extreme tempreatures, 15 and 30{degrees}C, exhibiting reduced mating success. Consequently, this led to a decrease in the production of adult offspring. Also these adult offspring underwent notable alterations in life history traits, reaching adulthood more rapidly at 25 and 30{degrees}C but with lower weight and reduced longevity. Furthermore, among these offspring, those produced by the cold-adapted D. ezoana were more vulnerable to desiccation and starvation compared to those from the warm-adapted D. novamexicana and the cosmopolitan D. virilis. In summary, our research underscores the intricate interplay between temperature, ecological adaptation and various life history traits in Drosophila species from distinct agro-ecological regions. The observed variations in CHC profiles, mating behavior, fertility and responses to environmental stressors collectively provide valuable insights into how environmental conditions shape the biology and ecology of insects.

ecology↗

bioRxiv2018

Dedicated acetic acid preference coded by broad spectrum ionotropic receptors in a moth species

Acetic acid as one of the food related odorant cues attracts many insect species. In the moth Mythimna separata, the olfaction of acid was coded via multiple pathways including 3 sensilla types on the antennae and 3 glomeruli in the antennal lobes. Among, suitable dosages of acetic acid exclusively activated DC3 glomerulus that receives integrated projections across sensilla types, which drives attractiveness and feeding attempts of the moth. This circuit encodes broad spectrum ionotropic receptors 8a, 75q1 and 75q2 which were sufficient to confer acid responsiveness in Xenopus oocytes. Ir75q2 was expressed in vivo with Ir75q1 and it enhanced sensitivity of the receptor functional group toward acids. Furthermore, Ir75q1 and Ir75q2 are both necessary for the moth to conduct acetic acid induced reactions of sensilla, DC3 glomerulus as well as attractiveness. Together, it reveals that an indispensable tetramer IR-based unit is employed to fulfill acetic acid specialized preference under suitable dosages through balancing of transcription and peripheral coding. Understanding of the Ir75q1/2 olfactory pathway provides insights into investigations on acid sensory process in insects.\n\nAuthor SummaryThe preference to acids are common in various organisms, and it may involve both olfactory and gustatory reception. In particular, airborne acidity volatiles can be sensed through antennae of insects and later assessed to help locating foraging, mating, and egg laying sites. However, these stimulatory processes can only be delivered by suitable dosages of acids, as we all know that, high acidity could be fatal in most circumstances. To date, avoidance to acids has been well explained in insects, but attractiveness and its basis remain uncharted. In the brain of oriental armyworm Mythimna separata, we have located 3 olfactory pathways which may play roles in acetic acid reception. Fortunately, when acetic acid was applied at attractive dosages, it only activated 1 dedicated pathway among the three. Later we found that this attractiveness pathway employed two ionotropic receptor genes namely Ir75q1 and Ir75q2, to successfully deliver this trait. Both genes were necessary for the moth to conduct acetic acid preference, but their roles are different. Ir75q1 recognized the acetic acid ligand and Ir75q2 later amplify the sensitivity. By comparing with evidences from electrophysiology and brain imaging tests, we found that the expression bias of either of the two genes has caused the separation of the pathways. It has been revealed in this moth that a smart decision system for olfactory reception exists, and this system may extrapolate to other insect species, as Ir75q1 and Ir75q2 are commonly expressed in many insect families.

neuroscience↗