marmoratus embryos (cleavage to early blastula
stage) to various concentrations of hygromycin B.
20-26) The high resistance at blastula
stage to physico chemical stress, enhanced in free living embryos by protective barriers like the vitelline membrane and jelly coats, provide support for the argument that its reflects very aggressive environmental conditions during the evolution of early multicellular organisms.
82) In accordance with the method, a piece of vector plasmid DNA was injected into either a fertilized mouse oocyte or one of the cells of an early embryonic stage, preferably prior to the eight-cell blastula
In the frog Xenopus, embryonic genes first become active when the embryo is a blastula
(a hollow sphere with a single layer of cells) about eight hours after fertilization.
Progeny ploidy at the blastula
stage was determined by chromosome counts and FCM analysis, and ploidy of later stages was determined by FCM.
This assay exposes to embryos from the small cell blastula
stage to a free living larvae to chemicals and mixtures to determine potential developmental toxicity.
For biochemical analyses, we used the material from 22 ripe females at the following stages: unfertilized eggs; embryos at 2-4 blastomeres (2 hr postfertilization), 16 blastomeres (3 hr), early blastula
The 9 stages of development (oviposition, first division of cleavage, 4-cell stage, 8-cell stage, morula, blastula
, gastrula, motion of larvae by velar rudiment, and early veliger stage) proposed by Chia and Koss (1978) and Buckland-Nicks et al.
This procedure exposed early blastula
embryos to a free living tadpole to the pyrethrin.
19) Gilbert notes how important placement is in the formation and further differentiation of the blastula
(Deuelopmental Biology 181-88); see n.
In the fruit fly, the blastula
is actually considered one large cell, even though it contains more than one nucleus.
Make no mistake: there is room for another historio-graphic-biography, for the Joyce industry has mitotically multiplied, morula upon blastula
into so many industrious schisms that it is often impossible to see the true wood of the family tree for the Clongowes Wood.
Acclimation of the sea cucumber Apostichopus japonicus to decreased salinity at the blastula
and gastrula stages: its effect on the desalination resistance of larvae at subsequent stages of development.
At small cell blastula
stage we placed the embryos into test solutions (renewed every 24 hrs).
Moreover, taking into account that intercellular adhesiveness exists in protists and occurs in amphibian embryos early in the blastula
stage (Herkovits 1978), the earliest multicellular life forms appear to be an ancient achievement in the anoxic Earth.