Editing Blastocoel (section)

== In amphibians ==
An amphibian embryo in the 128- cell stage is considered a blastula as the blastocoel in the embryo becomes apparent during this stage. The fluid-filled cavity forms in the [[Polarity in embryogenesis|animal hemisphere]] of the frog. However, the early formation of the blastocoel has been traced back to the very first [[cleavage furrow]]. It was demonstrated in the frog embryo that the first cleavage furrow widens in the animal hemisphere creating a small intercellular cavity that is sealed off via tight junctions.<ref name="Kalt"/> As cleavage continues, the cavity expands to become the developed blastocoel. The blastocoel is a crucial component of amphibian embryo development. It permits cell migration during gastrulation and prevents the cells beneath the blastocoel from interacting prematurely with the cells above the blastocoel. For instance, the blastocoel prevents the vegetal cells destined to become [[endoderm]] from coming in contact with those cells in the [[ectoderm]] fated to give rise to the skin and nerves.<ref name="Nieuwkoop">{{cite journal |last1=Nieuwkoop |first1=PD |title=The organization center of the amphibian embryo: its origin, spatial organization, and morphogenetic action |journal=Advances in Morphogenesis |volume=10 |pages=1–39 |year=1973 |doi=10.1016/b978-0-12-028610-2.50005-8 |pmid=4581327 |isbn=9780120286102 }}</ref>

=== Damage to blastocoel ===
The blastocoel can be damaged and abolished if the adhesion between blastomeres, provided by cell adhesion molecules like EP-cadherin, is destroyed as mRNA by [[oligonucleotide]]s. If the mRNA is destroyed, then there’s no EP-cadherin, little to no blastomere adhesion and the blastocoel is non-existent.<ref name="Heasman"/> During the next stage of embryonic development, amphibian [[gastrulation]], the blastocoel is displaced by the formation of the [[archenteron]], during mid-gastrulation. At the end of gastrulation, the blastocoel has been obliterated.<ref name="Purcell">{{cite journal |last1=Purcell |first1=SM |last2=Keller |first2=R |title=A different type of amphibian mesoderm morphogenesis in Ceratophrys ornata. |journal=Development |date=January 1993 |volume=117 |issue=1 |pages=307–17 |doi=10.1242/dev.117.1.307 |pmid=8223254}}</ref>