Fig. 1: RNAi and overexpression screening identifies myokines that regulate myofiber size in Drosophila body wall skeletal muscles. | Nature Communications

Fig. 1: RNAi and overexpression screening identifies myokines that regulate myofiber size in Drosophila body wall skeletal muscles.

From: The myokine Fibcd1 is an endogenous determinant of myofiber size and mitigates cancer-induced myofiber atrophy

Fig. 1

a Starting from 788 predicted secreted factors encoded by the Drosophila genome, 274 with human homology were selected based on a DIOPT homology score of ≥2. Of these, 111 secreted factors with substantial skeletal muscle expression (FPKM ≥ 4) were further chosen for screening with the UAS/Gal4 system and 508 transgenic stocks. b Transgenic RNAi or overexpression was driven in body wall skeletal muscle with Mef2-Gal4 and muscle phenotypes were identified first based on overall larval body size and secondarily with dissections and analysis of the size of a stereotypical set of skeletal muscles, ventral longitudinal VL3 and VL4 muscles, each consisting of a single myofiber. c Screen results (see Supplementary Data 1 for a full report): 31 interventions induced myofiber atrophy (6.1%), 12 led to myofiber hypertrophy (2.4%), whereas 465 led to no phenotype (91.5%). d Representative images of RNAi interventions that induce myofiber atrophy, compared to negative control RNAi. e Quantitation of the myofiber area, width, and length indicates a significant decrease; mean values ± SD and the precise n(VL3 + VL4 muscles from independent larvae) are reported in the figure; P < 0.001. Statistical analysis was done by using two-way ANOVA with Dunnett’s multiple comparison test. f Representative images of muscle size phenotypes induced by myokine overexpression, compared to a negative control (+; no transgene) and to positive controls (foxo and Insulin Receptor overexpression). g Quantitation of the myofiber area, width, and length indicates the significant induction of myofiber atrophy and hypertrophy by overexpression of the myokines indicated; mean values ± SD; the n(VL3 + VL4 muscles from independent larvae) is reported in the figure; P < 0.001. Statistical analysis was done by using two-way ANOVA with Dunnett’s multiple comparison test. Source data and complete statistical analyses are provided in the Source Data file.

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