blastula

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blas·tu·la

 (blăs′chə-lə)
n. pl. blas·tu·las or blas·tu·lae (-lē′)
An early embryonic form produced by cleavage of a fertilized ovum and consisting of a spherical layer of cells surrounding a fluid-filled cavity. Also called blastosphere.

[New Latin : from Greek blastos, bud + Latin -ula, feminine diminutive suff.]

blas′tu·lar adj.
blas′tu·la′tion (-lā′shən) n.

blastula

(ˈblæstjʊlə)
n, pl -las or -lae (-liː)
(Biology) an early form of an animal embryo that develops from a morula, consisting of a sphere of cells with a central cavity. Also called: blastosphere
[C19: New Latin; see blasto-]
ˈblastular adj

blas•tu•la

(ˈblæs tʃə lə)

n., pl. -las, -lae (-ˌli)
the early developmental stage of an animal, following the morula stage and consisting of a single spherical layer of cells enclosing a hollow, central cavity. Compare blastocyst.
[1885–90; < Greek blast(ós) bud, sprout + New Latin -ula -ule]
blas′tu•lar, adj.
blas`tu•la′tion (-ˈleɪ ʃən) n.

blas·tu·la

(blăs′chə-lə)
Plural blastulas or blastulae (blăs′chə-lē′)
An embryo at the stage immediately following the division of the fertilized egg cell, consisting of a ball-shaped layer of cells around a fluid-filled cavity. Compare gastrula.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.blastula - early stage of an embryo produced by cleavage of an ovumblastula - early stage of an embryo produced by cleavage of an ovum; a liquid-filled sphere whose wall is composed of a single layer of cells; during this stage (about eight days after fertilization) implantation in the wall of the uterus occurs
conceptus, fertilized egg, embryo - an animal organism in the early stages of growth and differentiation that in higher forms merge into fetal stages but in lower forms terminate in commencement of larval life
blastocele, blastocoel, blastocoele, cleavage cavity, segmentation cavity - the fluid-filled cavity inside a blastula
blastocyst, blastodermic vessicle - the blastula of a placental mammal in which some differentiation of cells has occurred
trophoblast - the membrane that forms the wall of the blastocyst in early development; aids implantation in the uterine wall; "after implantation of the blastocyst in the uterine wall the trophoblast divides into two layers, the chorion and the placenta"
Translations

blas·tu·la

n. blástula, etapa primitiva del óvulo.
References in periodicals archive ?
Blastulae were present from 9-14 h postfertilization, and gastrulae measuring 114.
Embryos released from females (following internal fertilization) were photographed, and videos were taken to document developmental stages from blastulae to free-swimming planulae (following methods in Lewis et al.
1995) Expression cloning of Siamois, Xenopus homeobox gene expressed in dorsal-vegetal cells of blastulae and able to induce a complete secondary axis.
The dipsomaniacs that returned late into the night from their pubs and made their customary urinovomitive halt in the sheltering murk of Sergeant Levarda sometimes found themselves with their noses against the window beyond which kaleidoscopic shapes were twisting and spinning and wobbling, rhodochrosite crystals that liqueified into throbbing exotic flowers sprouting lanceolate protuberances, quills that multiplied like a porcupine's, swords that blunted into milestones, into Gaelic cairns, then they rounded into seeds, swelled into colored drupes, into ink-blue blastulae, then into indigo morulae, so that in the end it all coalesced into one single large zygote of fluorescent plasma, hovering in the dark as if in a black hole.
Far from being as simple as the discussion of whether or not zygotes or blastulae are "persons" or have souls, the ethical issues regarding stem-cell research comprise a significantly more complicated milieu that includes the very foundation of scientific enquiry.
Fat was also extracted from blastulae and neonates, and lean dry mass was measured.
All other echinoids with nonfeeding larvae also form wrinkled blastulae (Raff 1987); blastulae in most species with obligate-feeding larvae are smooth.
Embryos become ciliated by 24 h, at which point the blastulae begin to rotate within their chorions (Fig.
2[degrees]C, the fertilized eggs rapidly reached the 2- and 4-cell stages at 10 and 44 min ACTT, respectively, became motile blastulae at 10 h ACTT, and developed further into early gastrulae (Fig.
Development was monitored through examination of random samples of 20 specimens collected from each culture, and the number of blastulae, gastrulae, and brachiolariae was assessed.
Ciliated, swimming blastulae with a small blastocoel were formed about 16 h after fertilization (Fig.
5 h Eight-cell embryos 9 h 16-cell embryos 23 h Unhatched blastulae; wrinkled with a clear blastocoel and irregular blastoderm 47 h * Hatched blastulae; apical tuft visible 73 h Initiation of gastrulation 4 days Mid-stage gastrulae; archenteron about 1/2 way into blastocoel 7 days Gastrulae that are compressed; first spicules visible with cross-polarized light 8 days Prisms 14 days Two-arm plutei with open mouths 33 days Four and six-arm plutei 48 days Formation of lobes begins 79 days Juvenile rudiments with podial buds and pedicellariae 120 days Metamorphosis; juvenile spine count ranges from 5 to 23 * Blastulae were unhatched at 23 and 33 h.