New Research on Animal Egg Orientation Shows “Unexpected” Diversity
Christian de Duve, eLife, embryo, embryonic development, Evidence, Evolution, evolutionary plasticity, evolutionary theory, evolutionists, genes, nucleic acids, proteins, unexpected, Urs Schmidt-Ott, Vital Dust, Yoseop Yoon, zygote
When the first cell of an animal — the zygote — divides, it usually has a front end, and a back end, and this orientation will influence how the embryo develops. This orientation is inherited from the egg, where certain gene products are deposited, often at the front end of the egg. These so-called anterior determinants signal the basic, front-back, orientation which is fundamental for the later embryonic development. But as is typical in biology, the specific genes involved often are not conserved across different species. As the summary of recent research explains: With very few exceptions, animals have “head” and “tail” ends that develop when they are an embryo. The genes involved in specifying these ends vary between species and even closely-related animals may use different genes for the…