The African striped mouse (four-striped grass mouse) is a species of rodent that is characterized by having in its back two longitudinal white bands bounded on either side by other dark. Dark bands are produced by pigmentation in melanocytes generated (dendritic cell whose main function is the production of melanin).
Until now, it was not known how these stripes were formed in mammals. A new study, published this week in Nature and that has had Spanish participation, has discovered the genetic and molecular mechanisms that produce patterns of stripes of different colors in the skin of mammals, based on the African striped mouse.
“The color patterns of mammals are one of the most recognizable features found in nature. In addition, can have a big impact on your health. However, until now we knew little about the mechanisms responsible for the formation and evolution of these patterns, “explains Mario Vallejo, researcher with Mercedes Mirasierra, Biomedical Research Center in Diabetes and Associated Metabolic Diseases (CIBERDEM) and the Institute Alberto Sols Biomedical Research (CSIC / UAM).
The main finding of this research, led by Hopi E. Hoekstra of Harvard University, is that the white bands are due to inhibition of a gene called Mitf which is essential for the function of melanocytes, and this inhibition takes out by a transcription factor (a regulatory protein) called Alx3.
Alx3 role in diabetes
The research group led by Vallejo several years the role that can have this same transcription factor Alx3 in diabetes. In an article published by the same team in early 2016 in the journal Diabetologia, the mechanism by which Alx3 represses gene expression in pancreatic islet glucagon described.
The way in which the repression of the activity Alx3 Mitf by explaining the Nature article may be similar to the same transcription factor used in the pancreas to suppress glucagon gene expression occurs.
In Diabetologia work, it described Alx3 levels in islet cells that produce glucagon (alpha cells) increase when levels rise in blood glucose. As a result, Alx3 interferes with transcription factor called Pax6 that is critical for the activity of the glucagon gene remains high, and therefore the activity of this gene in the presence of Alx3 decreases. Consequently glucagon levels generated in the pancreas also decrease.
In healthy people, when blood glucose levels are low, glucagon is released into the blood and acts on the liver, where glucose reserve deposits are stored. Thus glucose is released to meet the metabolic needs of the various tissues.
The problem is that in some diabetic patients, despite having abnormally high levels of glucose, the alpha cells secrete glucagon continue to manufacture and that by releasing activity of glucose from the liver does nothing but aggravate the problem. Scientists propose that Alx3 could be a key part of the regulatory mechanisms that may be altered in some diabetic patients.
Source: SINC
