Figure 3. Gonad migration errors.

a–e) Nomarksi microscopic images of male gonads in midbody region. a) N2 with normal gonad. b) CB4856 (Hw) with reversed gut/gonad asymmetry. c) Wild isolate (JU397) normal gonad with migration error where gonad begins on incorrectly on the left and corrects to grow on the right. d) Wild isolate (JU1172) with reversed gut/gonad orientation and migration error where the gonad begins correctly on the right and then mis-migrates to grow on the left. e) Wild isolate (JU1213) with normal gonad orientation and migration error with multiple midline crossing errors. False color in a–b gut is outlined in yellow and highlighted with pink. The gonad is outlined with white and highlighted with blue. c–e) Gonad is outlined in white; dashed white outline indicates the area of gonad that lies medially to the posterior end of the gonad. f) No significant correlation (n = 93 to 245, Kendall’s correlation τ (39) = 0.01, p = 0.91) between worms with a migration defect and worms with gut-gonad reversal. Wild isolates, black circles; N2, red square; Hw, green triangle. Strains used are listed in Materials and Methods. All images are presented with a ventral view and anterior to left. All experiments were carried out at 20°C.