A staging system for correct phenotype interpretation of mouse embryos harvested on embryonic day 14 (E14.5)
journal contributionposted on 14.08.2020, 14:53 by Stefan H Geyer, Lukas Reissig, Julia Rose, Robert Wilson, Fabrice Prin, Dorota Szumska, Ramiro Ramirez-Solis, Catherine Tudor, Jacqui White, Timothy J Mohun, Wolfgang J Weninger
We present a simple and quick system for accurately scoring the developmental progress of mouse embryos harvested on embryonic day 14 (E14.5). Based solely on the external appearance of the maturing forelimb, we provide a convenient way to distinguish six developmental sub-stages. Using a variety of objective morphometric data obtained from the commonly used C57BL/6N mouse strain, we show that these stages correlate precisely with the growth of the entire embryo and its organs. Applying the new staging system to phenotype analyses of E14.5 embryos of 58 embryonic lethal null mutant lines from the DMDD research programme (https://dmdd.org.uk) and its pilot, we show that homozygous mutant embryos are frequently delayed in development. To demonstrate the importance of our staging system for correct phenotype interpretation, we describe stage-specific changes of the palate, heart and gut, and provide examples in which correct diagnosis of malformations relies on correct staging.
Deciphering the Mechanisms of Developmental Disordersembryohigh-resolution episcopic microscopyknock outmorphologymutantAnimalsEmbryonic DevelopmentMiceMice, Inbred C57BLMice, KnockoutMutationPhenotypeSpecies SpecificityMohun FC001117Anatomy & Morphology0903 Biomedical Engineering1116 Medical Physiology