How nervous system senses and memorizes environmental conditions to regulate behavior is a fundamental question. The nematode Caenorhabditis elegans has unique features that facilitate elucidation of information processing, which mediate sensation and memory. Its nervous system contains only neurons 302, and their wiring pattern is known. In this review, we focused on the molecular and neural circuit mechanisms of a cultivation temperature experience-modulated behavior, thermotaxis of C. elegans. Thermotaxis is a useful model for studying complicated neural function, since simple neural circuit for thermotaxis is described previously. Recent molecular genetics and optogenetic technologies such as neural imaging and optical manipulation of neural activity have revealed molecular and cellular bases of thermotaxis behavior. Importantly, novel concept of neural calculation in the neural circuit between sensory neuron and interneuron has been identified.

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It is well established that honeybees inform their nestmates of the location of flowers they have visited by a unique behavior called a “waggle dance" discovered by Karl von Frisch who received Nobel Prize in 1973. On a vertical comb, the direction of the waggle run relative to gravity indicates the direction to the food source relative to the sun in the field, and the duration of the waggle run indicates the distance to the food source. By doing dance, a bee colony achieves an efficient foraging and a social adaptation to dynamically changing circumstance around a hive. Therefore, this behavior is also good model for communication mechanism and for adaptive behavior at a colony level. From this reason, even after publishing his famous book in 1963, many papers still have been published to show new interpretations of this sophisticated communication system. Here I will review dance behavior, with a great interest in dance information, based on our recent results as well as literatures from mainly behavioral analyses, but also neurophysiology, anatomy, and computer simulation. Finally, I will introduce the latest topics and discoveries that excite engineers as well as biologists.

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For researchers using non-model animal species, we here introduce the method of de novo transcriptome sequencing using Illumina short read data at a low cost. Sequence assembly without a reference genome is called de novo assembly. The absence of genome information has been a large disadvantage for transcriptome sequencing of non-model animals, because it makes transcriptome assembly difficult. The present technical note describes how to prepare the RNA sample, perform a deep RNA sequencing and de novo assembly. For de novo assembly, five assembly programs are compared: ABySS, Velvet, OASES, Trinity and Rnnotator. We also show how to classify the obtained sequences associated with gene ontology (GO) terms at the protein level annotation using BLAST2GO program. We hope this technical note will help the researchers to start a transcriptome analysis and facilitate the future genetic analysis of non-model animal.

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[in Japanese]

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