macromere


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macromere

[′mak·rō‚mir]
(embryology)
Any of the large blastomeres composing the vegetative hemisphere of telolecithal morulas and blastulas.
References in periodicals archive ?
Because of the crucial significance of macromere 3D and mesentoblast 4d for the specification of the developmental fate of the embryonic cells, it may be assumed that heterochronic changes in 3D induction may have far reaching morphogenetic consequences.
The 3D macromere serves as the organizer, and its removal at successively later stages during this time interval leads to fewer developmental defects.
During cleavage, gastropod Hb-like expression is uniform and labels both micromere and macromere nuclei (Fig.
For example, patellogastropods (true limpets) and euthyneuran gastropods (pulmonates and opisthobranchs) with equally cleaving eggs depend on regional segregation of morphogenetic determinants to specify the animal-vegetal axis (4), but an inductive interaction between micromeres and one of the macromeres later specifies the dorsoventral axis of the embryo (5, 6).
With third cleavage, MAPK was found exclusively within the two posterior midline macromeres. In living squid embryos, these cells undergo a delayed cleavage in comparison to the rest of the cells within the embryo.
Development of Ilyanassa following removal of the D macromere at successive cleavage stages.
Bravo-Hollis y Sanchez-Mejorada (1991) erigieron la serie Macromeres para ubicar a Coryphantha macromeris.
Gray Phyllodictyon anastomosans (Harvey) Kraft & Wynne (1; C; L) Phyllodictyon pulcherrimum Gray (C; NE) Familia Siphonocladaceae Chamaedoris Montagne, 1842 Chamaedoris peniculum (Ellis & Solander) Kuntze (S y C; L y A) Cladophoropsis B0rgesen 1905 Cladophoropsis macromeres W.
Similar to the current study, dominant species reported included Sargassum polycarpum, Turbinaria tricostata, and Cladophoropsis macromeres.
At this stage, the blastomeres divided unequally, creating cells of various sizes, including macromeres and micromeres (Fig.
The first two cleavages were equal and the third unequal, producing four micromeres and four macromeres at the animal and vegetal poles, respectively (Fig.