Not only in DNA's hands: Epigenetics has large say in blood formation

Epigenetics: environmental effects influence how genes are turned on and off. Credit: Weizmann Institute of Science

Blood stem cells have the potential to turn into any type of blood cell, whether it be the oxygen-carrying red blood cells, or the many types of white blood cells of the immune system that help fight infection. How exactly is the fate of these stem cells regulated? Preliminary findings from research conducted by scientists from the Weizmann Institute and the Hebrew University are starting to reshape the conventional understanding of the way blood stem cell fate decisions are controlled thanks to a new technique for epigenetic analysis they have developed. Understanding epigenetic mechanisms (environmental influences other than genetics) of cell fate could lead to the deciphering of the molecular mechanisms of many diseases, including immunological disorders, anemia, leukemia, and many more. It also lends strong support to findings that environmental factors and lifestyle play a more prominent role in shaping our destiny.

The process of differentiation – in which a stem cell becomes a specialized mature blood cell – is controlled by a cascade of events in which specific genes are turned "on" and "off" in a highly regulated and accurate order. The instructions for this process are contained within the DNA itself in short regulatory sequences. These regulatory regions are normally in a "closed" state masked by special proteins called histones to ensure against unwarranted activation. Therefore, to access and "activate" the instructions, this DNA mask needs to be "opened" by epigenetic modifications of the histones so it can be read by the necessary machinery.

In a paper published in Science, Dr. Ido Amit and David Lara-Astiaso of the Weizmann Institute's Immunology Department, together with Prof. Nir Friedman and Assaf Weiner of the Hebrew University of Jerusalem, charted for the first time histone dynamics during blood development. Thanks to the new technique for epigenetic profiling they developed, in which just a handful of cells – as few as 500 – can be sampled and analyzed accurately, they have identified the exact DNA sequences, as well as the various regulatory proteins, that are involved in regulating the process of blood stem .

Their research has also yielded unexpected results: As many as 50% of these regulatory sequences are established and opened during intermediate stages of cell development. This means that epigenetics is active at stages in which it had been thought that cell destiny was already set. "This changes our whole understanding of the process of blood stem ," says Lara-Astiaso, "suggesting that the process is more dynamic and flexible than previously thought."

Although this research was conducted on mouse , the scientists believe that the mechanism may hold true for other types of cells. "This research creates a lot of excitement in the field, as it sets the groundwork to study these regulatory elements in humans," says Weiner. Discovering the exact regulatory DNA sequence controlling stem cell fate as well as understanding its mechanism hold promise for the future development of diagnostic tools, personalized medicine, potential therapeutic and nutritional interventions, and perhaps even regenerative medicine, in which committed cells could be reprogrammed to their full stem cell potential.

More information: Science, www.sciencemag.org/content/ear… science.1256271.full

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JVK
1 / 5 (2) Aug 11, 2014
http://www.scienc...abstract
The authors do not specifically state that cell type differentiation of blood cells is nutrient-dependent and pheromone-controlled but our 1996 Hormones and Behavior review attested to that likelihood. We focused on sex differences in cell type differentiation, but the conserved molecular mechanisms we (TB) detailed are now showing up in the context of reports on cell type differentiation in all cells of all individuals in all species. Alternative splicing techniques of pre-mRNA appear to link nutrient uptake and ecological variation to amino acid substitutions and ecological adaptations controlled by the metabolism of nutrients to species-specific pheromones, which control the physiology of reproduction in species from microbes to man. See for review:" http://www.hawaii...ion.html
animah
5 / 5 (2) Aug 11, 2014
pheromone-controlled


Modern science: http://www.scienc...1100010X

The vomeronasal organ (the pheromone receptor organ) is thus nonfunctional in human adults. Other decisive arguments back up this conclusion. The genes coding for V1R-type receptor proteins are mostly deactivated by mutation: only five sequences remain in the human genome (whereas mice have more than 180!); the same is true for those coding for V2R-type receptor proteins. Moreover, the genes coding for the trpc2 channels, essential to vomeronasal neuron activation, are again pseudogenes unable to give rise to functional ion channels. These features are shared by New World monkeys and marine mammals. Finally, on histologic examination of the olfactory bulbs in humans and New World monkeys, the accessory olfactory bulbs are found to be absent

Thus spammer JVK - James V Kohl is a con man. The product you peddle, "scent of Eros" is snake oil.
JVK
1 / 5 (2) Aug 12, 2014
Processing by the main olfactory system of chemosignals that facilitate mammalian reproduction
http://www.scienc...14001196

The article was published in the same journal as our 1996 review. Eighteen years later, "The literature reviewed here documents the essential role of the main olfactory system in
the pheromonal facilitation of neuroendocrine and behavioral aspects of reproduction..." as detailed in our award-winning 2001 Neuroendocrinology Letters review: Human pheromones: integrating neuroendocrinology and ethology http://www.nel.ed...view.htm

Does everyone agree that if ignorant people don't hate you, you're probably not telling them about anything they need to learn?
animah
5 / 5 (2) Aug 12, 2014
JVK: The very study you linked and its references are clear: Most mammalian species -MOST- but not all and certainly not humans.

That only came to light in the last decade with widespread gene sequencing, but it is now a demonstrated fact.

You just cling to your old research because you need it to justify your commercial snake oil.
JVK
1 / 5 (2) Aug 12, 2014
The idea that cell type differentiation is not the result of conserved molecular mechanisms in species from microbes to man is derived from pseudoscientific nonsense associated with mutation-initiated natural selection and the evolution of biodiversity.

A detailed model of how ecological variation and nutrient-dependent amino acid substitutions differentiate cell types in all animals and how the metabolism of nutrients to species-specific pheromones controls their physiology of reproduction was published last year.
http://www.ncbi.n...3960065/

The article has been viewed nearly 6000 times this year, and it includes examples. One links the mouse model to a modern human population.

It is past time for intelligent people to comment on its content, and for ignorant people to stop telling others why they think human pheromones don't exist. The de novo creation of different cell type lineages shows that pheromones control ecological adaptations in all species.
JVK
1 / 5 (2) Aug 12, 2014
Alternatively, "...genomic conservation and constraint-breaking mutation is the ultimate source of all biological innovations and the enormous amount of biodiversity in this world." http://www.amazon...99661731

However, if you believe that, you have probably been taught to ignore biological facts like this: Feedback loops link odor and pheromone signaling with reproduction http://www.ncbi.n...16290036

It is more difficult to ignore reports like this one: Signaling Crosstalk: Integrating Nutrient Availability and Sex http://www.ncbi.n...3932994/

It links starvation in yeasts to nutrient-dependent pheromone-controlled ecological adaptations in other species via this report: Starvation-Induced Transgenerational Inheritance of Small RNAs in C. elegans http://www.cell.c...)00806-X

Thus the conserved molecular mechanisms of cell type differentiation in species from microbes to man refute a ridiculous theory.
animah
5 / 5 (2) Aug 12, 2014
JVK, how many times do we have to link to the genetic studies that demonstrate humans DO NOT HAVE expressed genes that would allow them to be receptive to pheromones. Old scammer James V Kohl, spruiker of fake sex perfume to the world's lost souls... Everyone on this forum laughs at you, and yet you blithely carry on making a fool of yourself.
JVK
1 / 5 (2) Aug 12, 2014
The model: The Mind's Eyes: Human pheromones, neuroscience, and male sexual preferences http://www.sexarc...kohl.htm

LeVay's comment
http://www.amazon...99737673
p. 210 This model is attractive in that it solves the "binding problem" of sexual attraction. By that I mean the problem of why all the different features of men or women (visual appearance and feel of face, body, and genitals; voice quality, smell; personality and behavior, etc.) attract people as a more or less coherent package representing one sex, rather than as an arbitrary collage of male and female characteristics. If all these characteristics come to be attractive because they were experienced in association with a male- or female-specific pheromone, then they will naturally go together even in the absence of complex genetically coded instructions."

The model links cause and effect across species.
JVK
1 / 5 (2) Aug 12, 2014
Sent by TB
Plasticity in the transcriptional and epigenetic circuits regulating dendritic cell lineage specification and function. http://www.ncbi.n...24820527

"To expand our understanding of lineage heterogeneity and functional activation states, we discuss the use of single cell genomics approaches in the context of a newly emerging systems immunology era, complementing the dichotomous definition of immune cells based solely on their surface marker expression. Rapid developments in single cell genomics are beginning to provide us with robust tools to potentially revise the working models of DC specification and the common hematopoietic tree."

The hemapoietic tree links the epigenetic landscape to the physical landscape of DNA in the organized genomes of every species that circulates blood via nutrient-dependent amino acid substitutions that differentiate all cells, which metabolize nutrients to species-specific pheromones that control the physiology of reproduction.
animah
5 / 5 (2) Aug 12, 2014
Scammer James V Kohl, having just quoted an islamic fundamentalist creationist on another thread as "supporting evidence" for your "theory", had another post yesterday ranting about Israeli schools, you have finally revealed the true extent of your lunatic belief.
JVK
1 / 5 (2) Aug 13, 2014
"...the so-called alpha chains of hemoglobin have identical sequences of amino acids in man and the chimpanzee, but they differ in a single amino acid (out of 141) in the gorilla." -- Dobzhansky (1973).

What kind of idiot challenges the Creationist beliefs of Dobzhansky, or the Islamic Creationist: Adnan Oktar, in the context of religion instead of what is known about biologically-based cause and effect?

No experimental evidence suggests that anything other than nutrient-dependent pheromone-controlled cell type differentiation (via amino acid substitutions) links ecological variation to ecological adaptations manifested in morphological and behavioral diversity in species from microbes to man.

Religion has nothing to do with the biological facts! The biological facts attest to Creation, not to the explanatory power of mutation-initiated natural selection and the evolution of biodiversity, which is a faith-based assumption in the pseudoscientific nonsense of population geneticists.
JVK
1 / 5 (2) Aug 13, 2014
Israeli Middle Schools School to Include Theory of Evolution http://www.educat...olution/

"...learning about evolution is not the primary function of the decision, but rather to use it as a building block for students to learn more about their ecology."

Apparently, they think it's easier to learn about how ecological variation leads to ecological adaptations if you also learn how ridiculous it is to place ecological adaptations into the context of mutation-initiated natural selection and the evolution of biodiversity.

I suspect that nearly everyone in Israel has already learned about nutrient-dependent pheromone-controlled ecological adaptations. See for example: Starvation-Induced Transgenerational Inheritance of Small RNAs in C. elegans

http://www.cell.c...)00806-X

Minimally, they know that starving organisms do not mutate into different species. That's unbelievable!