(n.) That stage in the development of the ovum in which the outer cells of the morula become more defined and form the blastoderm.
Example Sentences:
(1) The activity was maximum at the 16-32-cell stage and then decreased to a minimum at the mesenchyme blastula stage.
(2) In Lytechinus pictus, the protein cannot be detected in eggs or in embryos until the mesenchyme blastula stage.
(3) In the present study, ectodermal explants from Xenopus blastulae were shown to have high affinity binding sites for 125I-aFGF (Kd = 1.4 X 10(-10) M).
(4) In blastula nuclei, over half of the RNA synthesis is effected by polymerase II (inhibited by alpha-amanitin), the proportion remaining roughly constant with increasing ionic strength.
(5) The embryos incubated in vitro at the from blastula stage are characterized by the sharp activation of protein synthesis and the vegetal-animal gradient of protein synthesis, as well as in the control embryos; such embryos gastrulate and proceed to primary differentiation.
(6) Scanning electronmicroscopy examination showed that the morphology of NCH blastula cells, which were obtained from the combination of Tilapia nucleus and goldfish cytoplasm, manifested obviously abnormal features and the cells were arrested at different stages of cell disintegration.
(7) Measurements of absolute transcript abundance show that collagen mRNA is present in blastula primary mesenchyme cells at 600-700 copies per cell and at about fourfold lower amounts in other mesenchyme cells.
(8) beta-Catenin, recognized by an anti-arm antibody, is also present in the fertilized egg and in blastula-stage embryos.
(9) The tandemly repeated genes were expressed at a higher rate in blastula than in gastrula stage relative to the single-copy gene, when the two genes were injected into sea urchin zygotes.
(10) As a result, there is a loss of the 'compacted' epithelial surface of the blastula, an inability to close a wounded surface and defective gastrulation.
(11) This aggregation is prevented by Fab fragments obtained by immunization with purified membranes from blastula embryos.
(12) In S. purpuratus, the Hbox1 gene product probably is not involved in initial specification of cell fate, as this message does not achieve a significant fraction of its peak abundance until almost hatching blastula stage, well after the time aboral ectoderm cells have initiated a tissue-specific program of gene expression.
(13) First, using eggs at the blastula stage, the proper concentration of cadmium to which the eggs should be exposed was estimated.
(14) Actinomycin D is excluded from unfertilized eggs and developing embryos of the sea urchin Arbacia punctulata until the blastula hatches.
(15) We are investigating the mechanism by which animal cells of an amphibian blastula are induced to differentiate as muscle after contact with blastula vegetal cells.
(16) By the early blastula stage, most of the maternal tubulin sequences were associated with polysomes.
(17) The dynamics of protein synthesis in the loach embryos has been studied by means of autoradiography at the stages of cleavage, blastula and gastrula.
(18) The same material added to dissociated blastula cells, or to embryos at the blastula stage, stimulates skeleton formation and pigment cell differentiation.
(19) New embryonic rRNA transcripts are first detectable at the very early blastula stage.
(20) The nucleus-like structure was partitioned into blastomeres during cleavage through a process of nuclear fission, and was maintained in a group of extraordinarily large blastomeres until the blastula stage.
Morula
Definition:
(n.) The sphere or globular mass of cells (blastomeres), formed by the clevage of the ovum or egg in the first stages of its development; -- called also mulberry mass, segmentation sphere, and blastosphere. See Segmentation.
Example Sentences:
(1) Laminin was already present on the cell surface at the 2-cell stage, while nidogen was first detectable on compacted 8- to 16-cell stage morulae.
(2) Embryos bisected at blastocyst stages had a higher survival rate in vitro than those bisected at the morula stage.
(3) Rabbit morulae and blastocysts were cultured in conventional culture media [Ham's F10 or BSM II supplemented with bovine serum albumin (BSA) or serum] or in Ham's medium supplemented with synchronous or asynchronous uterine flushings, mostly for 2 days, and afterwards investigated by light and electron microscopy and by autoradiography.
(4) Compaction of the morula is a prerequisite for subsequent differentiation of the mouse embryo.
(5) The development stage of the embryo was determined after examination in toto at 24 h or by counting the morula nuclei at 60 h on histological sections.
(6) Day 6 sheep morulae were cultured in vitro for 48 hours in a bicarbonate-buffered salt solution supplemented with various concentrations of ovine serum or of these components or protein fractions of serum.
(7) Neither stain induced spontaneous activation in mouse oocytes, nor did they impair the in vitro development and implantation of mouse zygotes, two-cell embryos, stressed morulae or blastocysts.
(8) Ham's F-10 medium supplemented with hFCS is routinely checked for its ability to support mouse two-cell embryo development to morulae and blastocysts.
(9) After 6 months storage, the embryos (12, all at the compact morula stage), were thawed in a water bath at 39 degrees C for 30 minutes.
(10) All three treatments decompacted mid-morula-stage embryos within one hour.
(11) It has been reported that these tripronuclear oocytes can develop to grossly normal-appearing morulae and that chromosomally, these embryos could be triploid, diploid, or severely depleted.
(12) Late morulae to blastocysts (n = 80) were collected nonsurgically from naturally mated, estrous-synchronized, superovulated crossbred beef cows.
(13) Pronuclear stages were predominant at 42 to 48 hours and 3 to 8-cell stages at 72 to 96 hours; morulae (containing up to 95 cells) entered the uterus at seven days.
(14) The in vitro development of frozen thawed 4- and 8-cell embryos (23% and 21% respectively) was found to be significantly lower than that of frozen thawed morulae (89%).
(15) In morphological studies, insulin increased the number of blastocysts and decreased the number of morulae by 10% after 54 h culture from 2-cell embryos with EC50s of about 0.95 pM.
(16) Preimplantation stage (16-celled and morula) rabbit embryos were successfully frozen to -196 degrees C. The cooling rate (from a room temperature to 0 degrees C), the presence of the mucin layer surrounding embryos, the ice-seeding treatment and the thawing procedure were examined to determine their effects on the survival of the frozen embryos of Japanese white, New Zealand white and Dutch-Belted rabbits.
(17) Passage through this block (pb1-ratio) was determined by the ratio of compacted morula stages on day 4 of incubation.
(18) A culture system using cells from the uterine tube supported the development of one 1-cell embryo to the morula stage.
(19) Recipients receiving morulae and blastocysts that had incorporated an average of 384 d.p.m.
(20) The process whereby the morula becomes a fluid-filled cyst is called 'cavitation', which can be regarded as the first functional expression of the trophectoderm phenotype.