... for correspondence † Current address: Division of Biology, California Institute of Technology, Pasadena, CA 91125, USA 24 07 1992 © 1992 by Company of Biologists 1992 sea urchin dorsoventral axis NiCl 2 nickel Lytechinus variegatus mesenchyme skeleton Elaboration...

... of polar bodies and the formation of the egg pronucleus. We find that oocyte maturation takes approximately 9 hours in the species used here (Lytechinus variegatus), from the earliest indication of maturation (germinal vesicle movement) to formation of a distinct pronucleus. We then observed...

...Roberta R. Franks; Barbara R. Hough-Evans; Roy J. Britten; Eric H. Davidson A method is described for microinjection of cloned DNA into the zygote nucleus of Lytechinus variegatus . Eggs of this species are unusually transparent, facilitating visual monitoring of the injection process. The initial...