Tag: Zona pellucida
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Cleavage (embryology)
InĀ embryology,Ā cleavageĀ is the division ofĀ cellsĀ in the earlyĀ development of the embryo, followingĀ fertilization.Ā TheĀ zygotesĀ of many species undergo rapidĀ cell cyclesĀ with no significant overall growth, producing a cluster of cells the same size as the original zygote. The different cells derived from cleavage are calledĀ blastomeresĀ and form a compact mass called theĀ morula. Cleavage ends with the formation of theĀ blastula, or of theĀ blastocystĀ in…
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Vitellin is essential in the fertilization process, and embryonic development in egg-laying organisms
VitellinĀ is a protein found in theĀ egg yolk. It is a phosphoprotein.Ā Vitellin is a generic name for major of many yolk proteins. Vitellin has been known since the 1900s.Ā The periodic acid-Schiff method and Sudan black B dye was used to help determine that Vitellin is a glycolipoprotein because it stained positive when tested. This protein was…
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TheĀ trefoil knot foldĀ is aĀ proteinĀ foldĀ in which theĀ protein backboneĀ is twisted into aĀ trefoil knotĀ shape
“Shallow” knots in which the tail of the polypeptide chain only passes through a loop by a few residues are uncommon, but “deep” knots in which many residues are passed through the loop are extremely rare. Deep trefoil knots have been found in the SPOUT superfamily. including methyltransferase proteins involved in posttranscriptional RNA modification in all three domains of life, including bacterium Thermus thermophilus and…
