Definition of gastrula in US English:



  • An embryo at the stage following the blastula, when it is a hollow cup-shaped structure having three layers of cells.

    • ‘During gastrulation, cells on the outside of the embryo move inwards and, in animals such as the sea urchin, gastrulation even transforms a hollow spherical blastula into a gastrula with a hole through the middle - the gut.’
    • ‘The nucleus must be taken from the blastula and gastrula stages of frog embryos (at this point no semblance or form of the creature is distinguishable).’
    • ‘For example, most metazoans go through a developmental stage called a gastrula - a ball of cells with an infolding that later forms the gut.’
    • ‘Gastrulation in its broadest sense is the reorganization of the cells of the blastula to form a multilayered embryo, the gastrula.’
    • ‘Using light microscopy, he concluded that the embryo underwent gastrulation and that the gastrula consisted of three ‘cell elements’ on the outside, and two on the inside.’


Late 19th century: modern Latin, from Greek gastēr, gastr- ‘stomach’ + the Latin diminutive ending -ula.