Oxygen sensation and social feeding mediated by a C. elegans guanylate cyclase homologue

Specialized oxygen-sensing cells in the nervous system generate rapid behavioural responses to oxygen. We show here that the nematode Caenorhabditis elegans exhibits a strong behavioural preference for 5-12% oxygen, avoiding higher and lower oxygen levels. 3',5'-cyclic guanosine monophosphate (cGMP) is a common second messenger in sensory transduction and is implicated in oxygen sensation. Avoidance of high oxygen levels by C. elegans requires the sensory cGMP-gated channel tax-2/tax-4 and a specific soluble guanylate cyclase homologue, gcy-35. The GCY-35 haem domain binds molecular oxygen, unlike the haem domains of classical nitric-oxide-regulated guanylate cyclases. GCY-35 and TAX-4 mediate oxygen sensation in four sensory neurons that control a naturally polymorphic social feeding behaviour in C. elegans. Social feeding and related behaviours occur only when oxygen exceeds C. elegans' preferred level, and require gcy-35 activity. Our results suggest that GCY-35 is regulated by molecular oxygen, and that social feeding can be a behavioural strategy for responding to hyperoxic environments.     

《科学美国人》对诺贝尔奖获得者保罗·纳斯的专访研究细胞的组成是未来最激动人心的领域

20 0 0年 6月 ,《科学美国人》杂志记者卢里亚·卡罗瓦 (ＲｕｌｉａＫａｒｏｗ)在纽约冷泉港国家实验室采访了前来参加第 95届ＣＳＨ会议的英国科学家、 2 0 0 1年度诺贝尔生理学或医学奖获得者保罗·纳斯 (ＰａｕｌＭ .Ｎｕｒｓｅ) ;由于纳斯 2 0世纪 70年代在“细胞周期关键调节因子”方面的卓越工作揭示了细胞启动生长和分裂的机制 ,当时被认为是诺贝尔奖的理想候选人。以下是卡罗瓦与纳斯在冷泉港实验室外的草坪上进行的访谈内容。保罗·纳斯生于 1 944年 ,工作于英国皇家癌症研究基金会。 2 0世纪 70年代中期 ,他在裂殖酵母中发现了ｃ…