Biochemical controls: in embryo development (Introduction)

by David Turell , Wednesday, September 18, 2024, 20:16 (52 days ago) @ David Turell

A new epigenetic mark:

https://phys.org/news/2024-09-scientists-epigenetic-revealing-genes-early.html

"The team of Professor Christof Niehrs at the Institute of Molecular Biology (IMB) in Mainz, Germany, has discovered that a DNA modification called 5-formylcytosine (5fC) functions as an activating epigenetic switch that kick-starts genes in early embryonic development.

"This finding proves for the first time that vertebrates have more than one type of epigenetic DNA mark and sheds new light on how genes are regulated in the earliest stages of development.

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"This process of development depends on thousands of genes being activated at exactly the right time and place. The activation/deactivation of genes is controlled by so-called epigenetic modifications, i.e., chemical groups attached to DNA and its associated proteins that act like traffic lights to switch genes on or off.

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"Now, Niehrs and his team have shown for the first time that one of these modifications, 5-formylcytosine, is involved in activating genes in early development. The discovery is significant because it proves that vertebrates have more than one type of epigenetic DNA mark and uncovers a new, previously unknown mechanism of epigenetic gene regulation.

"'These findings are a real breakthrough in epigenetics because 5fC is only the second proven epigenetic DNA modification besides methylcytosine," said Niehrs, Founding and Scientific Director of the IMB, which was opened on the campus of Johannes Gutenberg University Mainz (JGU) in 2011.

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"To prove that 5fC is an activating epigenetic mark, the scientists genetically manipulated enzymes in the embryo to increase or decrease the amount of 5fC on the DNA. Increasing 5fC resulted in increased gene expression while decreasing 5fC reduced gene expression, indicating that it was indeed the presence of 5fC on the DNA that activates genes.

"Finally, the scientists also observed 5fC chromocenters in mouse embryos during zygotic gene activation. This suggested that 5fC likely acts as an activating epigenetic mark in both mammals and frogs.

"The revelation that 5fC is an activating epigenetic regulator on DNA raises many questions as to how exactly it acts and what its role is beyond early zygotic genome activation. In particular, cancer cells can have very high amounts of 5fC."

Comment: the development of an embryo must be precisely controlled to attain the desired result, a copy of the originals. How can that happen by chance evolution? Trial and error will never produce exact copies. Design is required.