Biological complexity: deciding red or white cell production (Introduction)

by David Turell , Wednesday, September 26, 2018, 20:51 (2250 days ago) @ David Turell

A new study has found the controls which help make the decisions:

https://medicalxpress.com/news/2018-09-white-blood-cell.html

"Using a genetic technique known as double knock-out (DKO), which represses two genes, rendering them non-functional, the scientists targeted Bach1 and Bach2 transcription factor proteins in mice. Transcription factors are proteins that control gene expression in cells by turning genes on or off according to certain stimuli. They found that red blood cell production was ineffective in the DKO mice, leading them to conclude that infection stimulates a reduced expression of Bach factors, which may contribute to the development of anemia of infection/inflammation.

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"According to lead author Hiroki Kato, a researcher in the Department of Biochemistry and the Department of Hematology and Rheumatology at Tohoku University Graduate School of Medicine in Sendai, Japan, transcription factors Bach1 and Bach2 support the formation of red blood cells by repressing white blood cell formation at the normal (healthy) state. Repressing Bach1 and Bach2 in the DKO mice induced the formation of white myeloid blood cells at the expense of producing red blood cells and another type of white blood cells called lymphoid cells.

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"The results of this study and previous research show that Bach factors play multiple roles in the formation of blood, such as supporting the formation of red blood cells and lymphoid cells from immature blood cells and the development and response of immune cells at mature cell levels, said Kato.

"'These facts suggest that Bach factors work as a 'switch' controlling the steady state as well as the emergency state of blood cell formation," Kato explained. "We would like to reveal the fundamental mechanism of the switching system."

"According to co-author Kazuhiko Igarashi, a scientist in the Department of Biochemistry and the Center for Regulatory Epigenome and Diseases at Tohoku University, the principle of blood cell formation: to be or not to be white myeloid cells, is regulated by a network of transcription factors—proteins that control the rate of transcription of genetic information from DNA to messenger RNA by binding to a specific DNA sequence.

"'Cells appear to stabilize their state of gene expression and thus identities by non-genetic modifications of chromatin," said Igarashi."

Comment: Once again we see the genomic system being manipulated by response to various stimuli. This is a built-in response by design because survival depends upon these quick responses