(n.) One of the segments first formed by the division of the ovum.
Example Sentences:
(1) Mouse embryos at the two-cell stage were separated into two individual blastomeres, and one blastomere was karyotyped at the second cleavage.
(2) Cleaved embryos with 'ideal' blastomere numbers (2, 4 or 8) showed a considerably higher metaphase frequency than others.
(3) Among the most conspicuous features found were the presence of very distinct desmosome-like structures between blastomeres, and the cytoplasmic cell organelles distribution in three areas referred as: a sub-cortical, a middle and a perinuclear bands.
(4) The procedure involves bisection of single-cell eggs in a medium containing cytochalasin; fusion of egg halves with single blastomeres, induced using Sendai virus or an electrofusion apparatus; and embedding in agar, followed by culture of the reconstituted embryos in the ligated oviducts of ewes in dioestrus.
(5) Lineage tracing techniques demonstrated that those cells in the ICM of early blastocysts which did possess filaments were almost exclusively the progeny of polar 16-cell blastomeres, suggesting that these filaments were directly inherited from outside cells at the 16- to 32-cell transition.
(6) Although the posterior-vegetal blastomeres (B4.1 pair) of the 8-cell embryo have long been believed to be the sole precursors of larval muscle, recent studies using horseradish peroxidase to mark cell lineages have shown that small numbers of muscle cells originate from the anterior-vegetal (A4.1) and posterior-animal (b4.2) blastomeres of this stage.
(7) Day 6 embryos were bisected and the resulting demiembryos were stained with Hoechst 33342 and cell counts were made by counting intact blastomere nuclei.
(8) Embryos developed at a normal rate after destruction of some blastomeres.
(9) The precise temporal and spatial coincidence of the patterns of polarization and the division cycles further suggests that a mechanistic link is maintained among cell division, blastomere polarization, and probably also a heritable component of the animal-vegetal axis.
(10) Each blastomere populated all three primary germ layers.
(11) The effect of destruction of some blastomeres on subsequent cleavage in vitro was investigated in the marsupial Antechinus stuartii.
(12) We conclude that, in general, analysing blastomeres is subject to less mis-diagnosis than polar body analysis, except in the case of dominant diseases which are caused by genes which lie extremely close to the centromere.
(13) The dexiotropic rotations of blastomeres were also observed during the division of the trypsinized zygotes with the tripolar mitotic apparatus.
(14) Primordial germ cells (PGCs), which formed in 78% of cases when the presumptive ventral half to the embryo was cultured, occurred in only 48% of cases when the two ventral vegetal blastomeres were cultured alone.
(15) Nematodes have been considered the chief paradigm for determinate and cell-autonomous development, but recent experiments on the early development of Caenorhabditis elegans suggest that most blastomeres of this nematode are, in fact, determined by interactions.
(16) A fluoresceinated lineage tracer was injected into individual blastomeres of eight-cell sea urchin (Strongylocentrotus purpuratus) embryos, and the location of the progeny of each blastomere was determined in the fully developed pluteus.
(17) Although blastocysts were well expanded, distinct signs of injury to the blastomeres were present, proceeding from loss of complete blastomeres to structural changes such as large lamellar structures, dilation of smooth endoplasmic reticulum and Golgi complexes, and clumping of mitochondria.
(18) The activity of HPRT, but not of APRT, was readily detectable in single 4-cell and 8-cell blastomeres.
(19) 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.
(20) To distinguish between these possibilities, we compared the fates of individual frog blastomeres between Li-treated embryos and normal embryos using lineage tracers.
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.