The study reveals the pattern and regulation mechanism of fruit fly population aggregation.

Recently, Zhuyan laboratory, Institute of Biophysics, Chinese Academy of Sciences, published an online article entitled "emergence of social cluster by collective pairwise encounterers in drophila" in eLife magazine. It revealed that under laboratory conditions, Drosophila spontaneously gathered to form stable and orderly colonies. This highly dynamic process involves a large number of but short-term inter individual interactions.in nature, many species, from microorganisms to human beings, exhibit amazing clustering phenomenon.it is a very important survival strategy for the same species to gather together to form a close group, which is helpful for foraging, resisting foreign enemies together, enhancing the sensitivity to changes in external environment, and enhancing group decision-making.the emergence of a highly ordered group structure from a disordered individual is an important life process and an important prerequisite for understanding the origin and stability mechanism of animal group behavior.fruit flies are generally considered as non social insects. However, some studies have found that Drosophila can show an aggregation trend without any external stimulation. How does the Drosophila self organize to form a stable colony? How to control the social distance among members of a group? What are the neural loop mechanisms that control this behavior? In recent years, Zhuyan laboratory has carried out a series of studies on the neural and molecular mechanisms of Drosophila socialization.in this study, the team found that clustering behavior depended on a large number of paired, asymmetric, short-term individual encounters, and the touching of the peripheral organs of two flies during the encounter was the key to trigger this behavior.further research found that deprivation of the five main perceptions can lead to abnormal encounters, which makes the whole group unable to form.in addition, it was found that PPK specific mechanical sensing neurons play an important role in the regulation of self-organizing behavior through neuronal inactivation and photogenetic activation.the results of in vivo functional imaging suggested that PPK neurons located at the tip of the legs of Drosophila melanogaster were specifically activated due to physical contact.using computer simulations of long-distance attraction and short-distance repulsion, the team found that this highly regular group structure can be achieved by relying on local individual perception and information exchange.Dr. Jiang Lifen is the first author of the paper, and other co authors include Cheng Yaxin, Gao Shan, Zhong Yincheng, Ma Chengrui and Wang Tianyu.researcher Zhu Yan is the corresponding author of the paper.the research was supported by NSFC, Chinese Academy of Sciences and State Key Laboratory of brain and cognition.figure: Drosophila self-organization aggregation, asymmetric encounter and regulation of PPK neurons.source: Institute of Biophysics, Chinese Academy of Sciences