SB347 males attracted to unablated animals (wild type), and ablated animals for precursors of germline (Z2 & Z3), vulva precursor cells (VPC) and precursors of somatic gonad (Z1 & Z4)

Data from figure 3e. 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. The values for the chemotaxis index (CI) were calculated with at least ten replicates for each condition. 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. Gonadal (Z1 – Z4) and vulva precursor cells (P5.p, P6.p and P7.p) of mid- L1 animals (females or hermaphrodites) were ablated using laser microsurgery. For ablation, worms were placed on agar pads on microscopic slides. Worms were recovered after ablation using a drop of M9 buffer and transferred to a normal seeded plate. Two days after recovery, laser ablated adult worms were used to collect supernatant for attraction assays