MaleMusFIG 23: Spicule retractor muscle attachment sites.

A. Epifluorescent image from transgenic animals expressing the egl-15 ::GFP reporter gene (FGF receptor), lateral, right medial plane. (Strain source: C. Branda and M. Stern.)
B. Epifluorescent image from transgenic animals expressing the hlh-8 ::GFP reporter gene (transcription factor), dorsal view. (Strain source: B.D. Harfe, M. Krause and A. Fire.)