Fig. 1.

(A) Holding K. marmoratus embryos in agarose grooves. Glass capillaries (outer diameter 1.2 mm) were cut into small pieces and placed in a 5 cm plastic petri dish. Agarose (1%) was poured into the dish and left to set (i). When solid, the gel was flipped to place the capillaries upward (ii). Capillaries were removed using fine tweezers (iii) molding grooves in the agarose that are of suitable sizes to hold eggs in place (iv). After filling the dish with 14‰ brackish water, eggs were gently inserted in the grooves using blunt foreceps (v). For injection, the animal pole was positioned so that the blastomere faced the injection needle (n). (B) Embedding dechorionated embryos in LMP agarose. Embryos were dechorionated (i and ii) and, using a large mouthed glass pipette, transferred to LMP agarose (at body temperature) (iii), and then immediately transferred to a glass-bottomed culture dish (iv). Before the agarose solidified, positions and angles of the embryos were adjusted by moving them gently with a glass capillary whose tip had been melted to form a smooth round edge.