本期封面是一只飞翔的普通吸血蝙蝠(Desmodus rotundus)，拍摄地在墨西哥。这些吸血蝙蝠具有特殊的本领，能检测红外辐射作为定位热血猎物身体的手段。除吸血蝙蝠外，这种“第六感”只存在其它3类脊椎动物，它们是 “远亲关系”的蛇—蝮蛇(pit vipers)、蟒蛇(pythons)和王蛇(boas)。对这3类蛇来说，红外传感器都是一个被称为“颊窝器”的面部结构。在蛇类中，一个非热敏性的离子通道(脊椎动物的TRPA1)是它们的红外探测器。正如本期Nature报告的那样，吸血蝙蝠探索红外线的分子机制稍有不同。在该机制下，RNA剪接导致产生TRPV1热敏通道的变体，它能适应较低的温度。将这一通道的基因序列与其他动物的做比对，在分子水平上支持这一假设：这些蝙蝠在演化上是与马、狗、母牛、鼹鼠和海豚（属于“劳亚兽总目”）属于一类的，而不是解剖学提出的那样——与人类、猴子和啮齿类（属于“灵长总目”）属于一类。
吸血蝙蝠
生物探索推荐英文摘要
Ganglion-specific splicing of TRPV1 underlies infrared sensation in vampire bats
Abstract：Vampire bats (Desmodus rotundus) are obligate blood feeders that have evolved specialized systems to suit their sanguinary lifestyle. Chief among such adaptations is the ability to detect infrared radiation as a means of locating hotspots on warm-blooded prey. Among vertebrates, only vampire bats, boas, pythons and pit vipers are capable of detecting infrared radiation. In each case, infrared signals are detected by trigeminal nerve fibres that innervate specialized pit organs on the animal’s face. Thus, vampire bats and snakes have taken thermosensation to the extreme by developing specialized systems for detecting infrared radiation. As such, these creatures provide a window into the molecular and genetic mechanisms underlying evolutionary tuning of thermoreceptors in a species-specific or cell-type-specific manner. Previously, we have shown that snakes co-opt a non-heat-sensitive channel, vertebrate TRPA1 (transient receptor potential cation channel A1), to produce an infrared detector6. Here we show that vampire bats tune a channel that is already heat-sensitive, TRPV1, by lowering its thermal activation threshold to about 30 °C. This is achieved through alternative splicing of TRPV1 transcripts to produce a channel with a truncated carboxy-terminal cytoplasmic domain. These splicing events occur exclusively in trigeminal ganglia, and not in dorsal root ganglia, thereby maintaining a role for TRPV1 as a detector of noxious heat in somatic afferents. This reflects a unique organization of the bat Trpv1 gene that we show to be characteristic of Laurasiatheria mammals (cows, dogs and moles), supporting a close phylogenetic relationship with bats. These findings reveal a novel molecular mechanism for physiological tuning of thermosensory nerve fibres.
