Fig. 6: Functional experiment of gene ben.
From: Single-cell transcriptomics reveals the brain evolution of web-building spiders
a, The expression level (transcripts per million, TPM) of gene ben across different tissues for Hylyphantes (n = 4 samples for abdomen, 3 for brain, 11 for legs, 3 for silk glands and 3 for venom glands). b, Gene ben showing up-regulated expression in web-building spider (n = 3 samples for Linyphiidae, n = 7 for Theridiidae) brains compared to burrowing spider brains (n = 8 for Heptathelidae and 4 for Atypidae). The log fold change (logFC) and significance between different predation strategies were calculated using two-sided Fisher’s test by EdgeR. Reported P value is FDR-adjusted using the Benjamini–Hochberg method. c, The expression level of ben was significantly reduced after dsRNA injection. Statistical comparisons were performed by Kruskal Wallis test followed by post-hoc Dunn’s correction. The green, yellow and blue bars represent three RNAi experiments. d,e, RNAi experiment to test the effect of ben knockdown on the web-building and prey capture capability. d, We removed all silk/webs in the plastic box after 24 h upon dsRNA injection and observed whether they would build webs in the same position. e, We dropped a fruit fly on the spider’s web after 24 h upon dsRNA injection and allowed the spider to perform its normal prey capture behaviour. After 10 minutes, we removed all the live fruit flies. f, Relative hub-position change of spider re-building web. ben-RNAi spiders (n = 19) showed slightly higher positional change than the control (n = 20). g, Comparison of supporting silken line length (SSt) between ben-RNAi (n = 33) and GFP control (n = 37). h, Comparison of gumfooted lines (GF) number between ben-RNAi (n = 39) and GFP control (n = 38). i, ben-RNAi (n = 5) spiders showed significantly lower capture success rate than the control (n = 5) during five days after RNAi. Box plots (a, b and c) show minimum to maximum (whiskers), 25–75% (box), median (band inside) with all data points. The solid line and dashed lines within each violin plot (f, g and h) indicate median and quartiles, respectively. Bars showed in i are mean ± SD across replicates. Statistical significance in f, g, h and i are reported using a two-tailed approach. Ben-RNAi spiders and control spiders showed in d–i are coloured in green and pink, respectively.
