[Changes in the dorsoventral polarity in frog eggs (Rana temporaria) under the influence of Ca2+ injections. The conditions for effecting a response].
The effect of local injections of Ca2+ solutions into Rana temporaria eggs during the period from fertilization to 1st cleavage division was studied. In most cases, microinjection of 2-5 nl of 1-20 mM Ca2+ solution into subcortical cytoplasm determined formation of the grey crescent (and the dorsal blastopore lip) at the site of injection. Injection of 0.1 mM Ca2+ or Ca(2+)-free solutions had no effect on the formation of the dorso-ventral axis. The effect of Ca2+ is more pronounced when the injection is made into vegetal part of the egg, close to the boundary between pigmented and non-pigmented zones, than into animal-equatorial part. Injections made during the 0.10-0.15 period of the first cell cycle produced greater effect than those made during the 0.40-0.45 period of the same cycle.
Bozhkova
V P
VP
Voronov
D A
DA
D000818:Animals; D002118:Calcium / Q000502:physiology*; D002970:Cleavage Stage, Ovum / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D008845:Microinjections / Q000379:methods; D010063:Ovum / Q000187:drug effects*; D011896:Rana temporaria; D013997:Time Factors; D015053:Zygote / Q000187:drug effects
D002118:Calcium
Izmenenie dorso-ventral'noĭ poliarnosti v iaĭtsakh liagushki (Rana temporaria) pod vliianiem in''ektsiĭ Ca2+. Usloviia éffektivnosti otveta.