What's the difference between embryo and gastrula?

Embryo


Definition:

  • (n.) The first rudiments of an organism, whether animal or plant
  • (n.) The young of an animal in the womb, or more specifically, before its parts are developed and it becomes a fetus (see Fetus).
  • (n.) The germ of the plant, which is inclosed in the seed and which is developed by germination.
  • (a.) Pertaining to an embryo; rudimentary; undeveloped; as, an embryo bud.

Example Sentences:

  • (1) It was found that the skeletal muscle enzyme of the chick embryo is independent of the presence of creatine and consequently is another constitutive enzyme like the creatine kinase of the early embryonic chick heart.
  • (2) Since 1987, it has become possible to obtain immature ova from the living animal and to let them mature, fertilize and develop into embryos capable of transplantation outside the body.
  • (3) In X-irradiated litters, almost invariably, the incidence of anophthalmia was higher in exencephalic than in nonexencephalic embryos and the ratio of these incidences (relative risk) decreased toward 1 with increasing dose.
  • (4) The effects of hormonal promotion of T24-ras oncogene-transfected rat embryo fibroblasts (REF) were compared to cotransformation of these cells with adenovirus E1A and ras.
  • (5) Scatchard analyses of binding data obtained with synaptosomal preparations from 17-day-old embryos revealed two T3 binding sites.
  • (6) In the stage 24 chick embryo, a paced increase in heart rate reduces stroke volume, presumably by rate-dependent decrease in passive filling.
  • (7) From the biochemical markers in follicular fluid, cyclic adenosine monophosphate has a distinct predictive value in regard to pregnancy in in vitro fertilization-embryo transfer cycles.
  • (8) Implantation of the mouse embryo involves the invasion of the secondary trophoblast giant cells of the ectoplacental cone (EPC) into the uterine decidua.
  • (9) They suggest that an endogenous retinoid could contribute to positional information in the early Xenopus embryo.
  • (10) A cytogenetic and anatomopathologic study of an embryo of 24 mm crown-rump length showing pure triploidy (69,XXY) is reported.
  • (11) The in vivo approach consisted of interspecies grafting between quail and chick embryos.
  • (12) Here we report direct measurements of protein kinase C (PKC) activity in uninduced ectoderm, and in neuroectoderm shortly after induction by the involuting mesoderm, in Xenopus laevis embryos.
  • (13) Results obtained from cumulative labeling and pulse-labeling and chase experiments with cells from late gastrulae, yolk plug-stage embryos, and neurulae showed that the 30S RNA is an intermediate in rRNA processing and is derived from 40S pre-rRNA and processed to 28S rRNA.
  • (14) During that time they have repeatedly demonstrated the likely existence of signalling molecules or morphogens that control the pattern of development in the embryo.
  • (15) Ernst Reissner studied the formation of the inner ear initially using the embryos of fowls, then the embryos of mammals, mainly cows and pigs, and to a less extent the embryos of man.
  • (16) The objective of this study was to examine the effects of different culture media used for maturation of bovine oocytes on in vitro embryo development following in vitro fertilization.
  • (17) By 3 d in the chick embryo, the first neurons detected by antibodies to Ng-CAM are located in the ventral neural tube; these precursors of motor neurons emit well-stained fibers to the periphery.
  • (18) None of the factors tested was found to have a statistically significant effect on embryo yield.
  • (19) The embryo stages were assessed visually and some were investigated histologically.
  • (20) Ninety semen specimens were analysed for use in an IVF-embryo transfer (ET) programme.

Gastrula


Definition:

  • (n.) An embryonic form having its origin in the invagination or pushing in of the wall of the planula or blastula (the blastosphere) on one side, thus giving rise to a double-walled sac, with one opening or mouth (the blastopore) which leads into the cavity (the archenteron) lined by the inner wall (the hypoblast). See Illust. under Invagination. In a more general sense, an ideal stage in embryonic development. See Gastraea.
  • (a.) Of or pertaining to a gastrula.

Example Sentences:

  • (1) Results obtained from cumulative labeling and pulse-labeling and chase experiments with cells from late gastrulae, yolk plug-stage embryos, and neurulae showed that the 30S RNA is an intermediate in rRNA processing and is derived from 40S pre-rRNA and processed to 28S rRNA.
  • (2) Cells falling off from ectoderm were observed in normally developing gastrulae of the newt, Cynops pyrrhogaster, in light microscopic examination.
  • (3) Among such genes, particular interest is focused on three genes encoding putative transcription factors that are expressed specifically in the Spemann organizer region of the gastrula.
  • (4) Their synthesis is first detectable in stage IV oocytes and continues throughout early embryogenesis until the late gastrula.
  • (5) 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.
  • (6) RA was applied for one hour at concentrations ranging from 10(-9) to 10(-6) M to embryos at 50% epiboly, the midgastrula stage, and at 10(-7) M to embryos at early and late gastrula stages.
  • (7) In gastrulae, spectrin accumulates near the embryo surface, especially at the forming amnioproctodeal invagination and cephalic furrow.
  • (8) The dynamics of protein synthesis in the loach embryos has been studied by means of autoradiography at the stages of cleavage, blastula and gastrula.
  • (9) GAD activity was undetectable at the early gastrula stage (stage 8a) and was slightly measurable at the early neurula stage (stage 14- onset of the culture).
  • (10) However, we established an enhanced level of [14C]acetate incorporation at the time of extensive gene activation during gastrulation as well as some quantitative differences in the pattern of acetylation during gastrula and organogenesis.
  • (11) RNase protection assays demonstrate that transcripts encoding alpha, gamma, and delta subunits are coordinately expressed at late gastrula and that the amount of each transcript increases in parallel with muscle-specific actin mRNA during the ensuing 12 h. After the onset of muscle activity the level of actin mRNA per somite remains relatively constant, whereas the level of alpha subunit and delta subunit transcripts decrease fourfold per somite and the level of gamma subunit transcript decreases greater than 50-fold per somite.
  • (12) When the supernatant proteins from eggs and gastrulae were subjected to size-exclusion HPLC the neural inducing activity was eluted in different size classes, suggesting a limited proteolysis of a precursor during early embryogenesis.
  • (13) Isolated neuroblasts from gastrula-stage Drosophila embryos divide and differentiate in vitro to produce clonally derived clusters of neurons.
  • (14) In both fish embryos, the COI and COII transcripts declined gradually after fertilization until late-blastula stage and then increased in early gastrula stage.
  • (15) Three of these clones are not represented in the maternal RNA population but are activated at the late gastrula stage; the other three increase from a maternal base.
  • (16) This led to an attempt to discover the molecular character of cell action by means of transfilter induction in early gastrula ectoderm of Xenopus laevis.
  • (17) We have demonstrated that a 'wave' of DNA synthesis occurs in the neurectoderm of Xenopus laevis gastrula.
  • (18) When Xenopus blastula or early gastrula ectoderm is disaggregated and cells are kept dispersed for up to 5 h prior to reaggregation, the resulting spheres will differentiate into large neural structures.
  • (19) Yolky tissue from the vegetal hemisphere of the gastrula or the archenteron floor of the neurula synthesized mainly polydisperse material of high molecular weight rather than discrete glycoproteins.
  • (20) The transgenome replicates intensively during the course of early development (until the blastula--early gastrula stages), but later the replication slows down which results in the elimination of the transgenome from the majority of embryos at more advanced stages.