自上世紀(jì)初以來,，科學(xué)家就已經(jīng)知道很多生物具有探測(cè)環(huán)境濕度的能力。實(shí)際上,，對(duì)很多生物來說,，這種能力是生存的關(guān)鍵。昆蟲身體很小,，這使得它們對(duì)于濕度的變化尤其敏感,，因此昆蟲一直是研究這種感覺能力的最好模型。然而,，盡管科學(xué)家作了很多努力,，但這種感覺的細(xì)胞和分子機(jī)制仍然是一個(gè)謎。現(xiàn)在,，Liu等人提供了關(guān)于這一復(fù)雜感覺體系中所涉及的分子機(jī)制的一些線索,。他們發(fā)現(xiàn),，果蠅的3個(gè)TRP通道參與濕度的探測(cè)：water witch (ww)是探測(cè)潮濕空氣所需要的，而nanchung (nan)和inactive (iav)是探測(cè)干燥空氣所需要的,。他們還發(fā)現(xiàn),，表達(dá)這些通道的神經(jīng)元能夠刺激果蠅觸角上不同的傳感性茸毛。機(jī)械傳感模塊可能是決定果蠅探測(cè)其所碰到的環(huán)境提示能力的生理基礎(chǔ),，而這些環(huán)境提示也許又能使環(huán)境中水分含量的微小變化能被探測(cè)到,。
原始出處:
Nature 450, 294-298 (8 November 2007) | doi:10.1038/nature06223; Received 25 June 2007; Accepted 3 September 2007
Drosophila hygrosensation requires the TRP channels water witch and nanchung
Lei Liu1, Yuhong Li1, Runping Wang1,2, Chong Yin3, Qian Dong1,2, Huey Hing3, Changsoo Kim4 & Michael J. Welsh1,2
Departments of Internal Medicine,
Departments of Physiology and Biophysics, Howard Hughes Medical Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA
Department of Cell and Structure Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju 500-757, Korea
Correspondence to: Michael J. Welsh1,2 Correspondence and requests for materials should be addressed to M.J.W. (Email: [email protected]).
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The ability to detect variations in humidity is critical for many animals. Birds, reptiles and insects all show preferences for specific humidities that influence their mating, reproduction and geographic distribution1, 2. Because of their large surface area to volume ratio, insects are particularly sensitive to humidity, and its detection can influence their survival3, 4, 5, 6, 7. Two types of hygroreceptors exist in insects: one responds to an increase (moist receptor) and the other to a reduction (dry receptor) in humidity4, 6, 8. Although previous data indicated that mechanosensation might contribute to hygrosensation6, 9, the cellular basis of hygrosensation and the genes involved in detecting humidity remain unknown. To understand better the molecular bases of humidity sensing, we investigated several genes encoding channels associated with mechanosensation, thermosensing or water transport. Here we identify two Drosophila melanogaster transient receptor potential channels needed for sensing humidity: CG31284, named by us water witch (wtrw), which is required to detect moist air, and nanchung (nan), which is involved in detecting dry air. Neurons associated with specialized sensory hairs in the third segment of the antenna express these channels, and neurons expressing wtrw and nan project to central nervous system regions associated with mechanosensation. Construction of the hygrosensing system with opposing receptors may allow an organism to very sensitively detect changes in environmental humidity.
