Cambridge scientists have discovered the stage at which some of the cells of a fertilised mammalian egg are fated to develop into stem cells and why this occurs. The findings of the study, which overturn the long-held belief that cells are the same until the fourth cleavage (division) of the embryo, are reported in today's edition of Nature.
After fertilisation, the cells of the embryo at first undergo equal, symmetrical divisions and unequal, asymmetrical ones that direct smaller daughter cells towards the inside of the embryo. These become the inner cell mass of stem cells. Previously, it was believed that the mammalian embryo starts its development with identical cells and only as these inside and outside cells form do differences between cells first emerge.
However, research led by Professor Magdelena Zernicka-Goetz, University of Cambridge, has revealed evidence to suggest that differences between the embryonic cells are already apparent at the 4-cell-stage, before the cells become partitioned between the inside or outside of the embryo. And those differences depend on the orientation and order of the very first cleavage divisions of the embryo.
Professor Zernicka-Goetz said, "Our findings were surprising since they showed that cells of the mammalian embryo first start to differ from each other much earlier in development than previously supposed but also they give us a real clue on how to manipulate embryonic cells so that they will develop with the properties of the natural stem cells of the embryo."
The study also found cell fate and transcription activity is determined by the level of a methylated form of histone H3, one of the basic proteins around which DNA is packaged and which when modified in this way affects gene expression. They found that the higher the levels of this modified form of histone H3, the more predisposed the mammalian embryonic cells were to develop the qualities of inner embryonic cells, a population that have stem-cell-like properties. Thus, their results show that manipulating epigenetic information in this protein in early mouse embryos can influence cell fate determination.
Genevieve Maul | EurekAlert!
Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University
How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy