Gene genie

[Jo Bowyer]

How glial cells develop in the brain from neural precursor cells

https://www.sciencedaily.com/release...1210105359.htm

A research team studied how glial cells develop in the brain from neural precursor cells. They discovered that differentiation involves three stages and that three proteins in the cell nucleus, so-called transcription factors, play a key role in organizing glia-specific transcription of the genes in the cell nucleus.

[Jo Bowyer]

Unexpected Link Between Feeding and Memory Brain Areas Discovered

https://neurosciencenews.com/memory-...g-brain-10594/

“What struck us the most was that the process by which NCOR1/2 regulates memory involves a new circuit that links two brain regions: the lateral hypothalamus, known as a feeding center of the brain, and the hippocampus, a place that stores memory,” Xu said. “It surprised us because the hypothalamus is not traditionally considered to be a major regulator of learning and memory.”

“Mechanisms underlying these associations are not completely clear,” Sun said. “We think that the NCOR1/2-regulated neural circuit between the feeding and the memory centers of the brain we have discovered is worth exploring further in this context.”
“The gene NCOR1 is located on human chromosome 17, very close to the region that has been previously implicated in the Potocki-Lupski and Smith-Magenis syndromes,” Liu explains. “We have always suspected that mutations of this gene could cause intellectual disabilities or other deleterious neurological consequences. The mouse models in the current study provide the first evidence that this is indeed the case.”

These findings have implications for the relationships among endocrine factors, obesity and metabolic disorders and cognitive dysfunctions such as Alzheimer’s disease. It is known, for instance, that people with endocrine disruption or metabolic disorders are more susceptible to Alzheimer’s disease.

[Jo Bowyer]

Making 'sense' of the 'cart before the horse' in mammalian cells

https://www.sciencedaily.com/release...0128142502.htm

[Jo Bowyer]

Newly Discovered Gene Governs Need for Sleep When Sick

https://neurosciencenews.com/genetic...s-sleep-10676/

[Jo Bowyer]

Here are 5 RNAs that are stepping out of DNA’s shadow

https://www.sciencenews.org/article/...orspicks040719

DNA is the glamour molecule of the genetics world. Its instructions are credited with defining appearance, personality and health. And the proteins that result from DNA’s directives get credit for doing most of the work in our cells. RNA, if mentioned at all, is considered a mere messenger, a go-between — easy to ignore. Until now.

RNAs, composed of strings of genetic letters called nucleotides, are best known for ferrying instructions from the genes in our DNA to ribosomes, the machines in cells that build proteins. But in the last decade or so, researchers have realized just how much more RNAs can do — how much they control, even. In particular, scientists are finding RNAs that influence health and disease yet have nothing to do with being messengers.

The sheer number and variety of noncoding RNAs, those that don’t ferry protein-building instructions, give some clues to their importance. So far, researchers have cataloged more than 25,000 genes with instructions for noncoding RNAs in the human genome, or genetic instruction book (SN: 10/13/18, p. 5). That’s more than the estimated 21,000 or so genes that code for proteins.

[Jo Bowyer]

Redefining normal: Study shows mutations even in healthy tissues throughout the body

https://www.statnews.com/2019/06/06/...eb87-151138121

For years, the prevailing wisdom has been that our cells contain genes that are essentially carbon copies of each other. That notion is being dashed by studies painting a different picture — one in which even “normal” cells and tissues accumulate mutations over time.

This is a recurrent theme in the external neuroscience lectures at The Crick Institute. Are they mutations or adaptations........

[Jo Bowyer]

Networks of gene activity control organ development

https://www.sciencedaily.com/release...0626133708.htm

The fundamental and original gene activity networks that the researchers discovered function similarly and determine key developmental processes in all the mammals studied, including humans. That means that these molecular networks already controlled organ development of early mammals 200 million years ago.

The researchers also found a surprisingly large number of genes whose activity patterns deviated significantly from one another in the various species of mammals. These differences, which arose during the course of evolution, explain the specific organ traits of the respective species. For the genes that control brain development, for example, the Heidelberg researchers were able to identify distinct expression patterns in humans. The scientists also discovered that a surprisingly large number of RNA genes are involved in the control of organ development.

[Jo Bowyer]

DNA repeats -- the genome's dark matter

First direct analysis of pathogenic sequence repeats in the human genome

https://www.sciencedaily.com/release...1122113256.htm

[Jo Bowyer]

How stem cells decide their identity

https://www.sciencedaily.com/release...1203102022.htm

The undifferentiated stem cells of the embryo develop either into cells of the nervous system, the so-called neuroectoderm, or into cells of the meso- and endoderm, from which, for example, many different cell types of the internal organs or the muscles develop. For over 25 years it has been known that this decision is regulated by embryonic signaling molecules, such as TGFβ and Wnt signals. So far, however, it has remained unclear exactly how these signals control this first decision of cell differentiation. The study, carried out in the context of Tosic's doctoral thesis, shows that the embryonic TGFβ and Wnt signals are transmitted by gene-regulating transcription factors of the T-box factor family, namely Eomes and Brachyury. These factors are responsible for "turning on" the differentiation gene programs for all meso- and endoderm cells. At the same time, these T-box factors also act as gene repressors, preventing the formation of neural tissue by suppressing the corresponding gene programs. This involves changes in the structure but not the content of the genetic information in the cell nucleus.

I attended a lecture at The Crick last week given by Prof Thomas C. G. Bosch (University of Kiel) entitled "Nature's oldest neurons are immune-competent cells interacting with microbes" he and his group are working with Hydra, my favourite animalicule. He said that the first nervous system to evolve was the enteric nervous system, not the CNS. Which would fit in with the necessity for the interaction of early neurons with microbes. It is hoped that his research will inform ageing and immunological senescence.

The ectodermalists amongst you can take comfort from the fact that meso and endodermal cells have to be turned on by gene transcription factors, and formation of neural tissue has to be repressed, in order to allow formation of a body.