blastocyst is an embryo during the late stages of development.
blastocyst is an embryo during the late stages of development.
an embryo during the late stages of development?
blastocyst
her recent development of systems permitting both mouse and human embryogenesis during implantation and early post-implantation stages "in vitro" allowed her to reveal that mouse and human embryo remodelling at implantation is done autonomously by the embryo. she uncovered the mechanism underlying embryo remodelling between the blastocyst and gastrula stages that has led to a change in the textbook model. her demonstration of the self-organisation of human embryos developing "in vitro" until day 13/14, gastrulation, has provided an unprecedented opportunity to study human development at previously inaccessible and critical stages. this discovery was hailed as the people's choice for the scientific breakthrough of 2016 by science magazine. the knowledge she gained through her work on how the embryo develops during the blastocyst to gastrula transition, allowed her to mimic these developmental processes with different types of stem cells in vitro. this led her to the pioneering success of constructing embryo-like structures from pluripotent embryonic and multipotent extra-embryonic (trophoblast) stem cells in a 3d scaffold of extra-cellular matrix proteins in vitro. these "synthetic embryos" recapitulate the natural architecture of the embryo and their patterns of gene expression leading to the specification of the germ layers and germ cells. this system allowed her to identify signalling pathways responsible for morphogenesis of stem cells into embryos. together these models bring outstanding potential for understanding development and for regenerative medicine.
magdalena zernicka-goetz
gene expression of the brain changes throughout the different phases of life. the most significant levels of expression are found during early development, with the rate of gene expression being highest during fetal development. this results from the rapid growth of neurons in the embryo. neurons at this stage are undergoing neuronal differentiation, cell proliferation, migration events and dendritic and synaptic development. gene expression patterns shift closer towards specialized functional profiles during embryonic development, however, certain developmental steps are still ongoing at parturition. consequently, gene expression profiles of the two brain hemispheres appear asymmetrical at birth. at birth, gene expression profiles appear asymmetrical between brain hemispheres. as development continues, the gene expression profiles become similar between the hemispheres. given a healthy adult, expression profiles stay relatively consistent from the late twenties into the late forties. from the fifties onwards, there is significant decrease in the expression of genes important for regular function. despite this, there is an increase in the diversity of genes being expressed across the brain. this age related change in expression may be correlated with gc content. at later stages of life, there is an increase in the induction of low gc-content pivotal genes as well as an increase in the repression of high gc-content pivotal genes. another cause of the shift in gene diversity is the accumulation of mutations and dna damage. gene expression studies show that genes that accrue these age-related mutations are consistent between individuals in the aging population. genes that are highly expressed at development decrease significantly at late stages in life, whereas genes that are highly repressed at development increase significantly at the late stages.
neurogenomics