Rhabditis sp. SB347 male, female and hermaphrodite attraction to ascr#1 and ascr#9

Data from figure S1. To quantify the degree of attraction of worms to conditioned medium produced by different sexes, we used chemotaxis assays. Conditioned medium (henceforth referred to as ‘supernatant’) was generated by placing 5-10 worms in 100 µL of M9 buffer for 12 h at room temperature. The supernatant was stored in 10 µL aliquots at -20 °C until required. The assay was performed either on a microscope slide with a layer of 1.5% agar placed on top of an empty plate, or on a 6 cm NGM plate. 3 µL of supernatant was added on one side of the slide and 3 cm apart from the control drop that just contained M9. 15 young-adults were placed on the midline between the spots. After 30 min, worms were scored on the basis of their location. To calculate the CI, the number of worms attracted to the test spot were subtracted by the number of worms in the control spot, and divided by the total number of males assayed. A CI of one indicates that all worms are attracted to the chemical in the test spot, whereas a CI close to zero indicates no attraction.

本数据源自补充图S1。为量化线虫对不同性别个体所产生的条件培养基的趋化程度，本研究采用趋化性实验（chemotaxis assays）。条件培养基（以下简称"上清液"）的制备方法为：将5~10条线虫置于100 μL M9缓冲液中，于室温孵育12小时。随后将上清液以10 μL的分装量保存于-20 ℃冰箱，直至实验所需时取用。实验可在两种载体上开展：一种是在空培养皿上铺有1.5%琼脂（agar）层的显微镜载玻片，另一种是直径6 cm的NGM培养板。在载玻片的一侧滴加3 μL上清液，与仅含M9缓冲液的对照液滴相距3 cm。将15条青年成虫置于两个液滴之间的中线上。30分钟后，根据线虫所处位置进行计数评分。为计算趋化指数（Chemotaxis Index, CI），用被吸引至检测液滴的线虫数量减去对照液滴中的线虫数量，再除以本次实验所检测的雄性线虫总数量。当CI为1时，代表所有线虫均被检测液滴中的化学物质吸引；而当CI接近0时，则表明线虫无明显趋化倾向。