Humanโข Accelerated Regions & brain Development: Aโ Summary
Scientists have been โstudying “Human Accelerated Regions” (HARs) – sections of our DNA that are highly conserved in other mammals but have changed rapidly inโ teh human lineage since we diverged evolutionarily. Around โค3000 of these HARs haveโฃ been identified, โtypically โaveraging 260 base pairs in length.
Interestingly, most HARs don’t code for proteins themselves, but instead act asโ regulators of gene โคexpression, essentially controlling when, how much, and how strongly other genes are activated during โdevelopment – like “molecular volume controls.”
Recent research at UC San diego has focused on โ HAR123, which is present in โฃchimpanzees and mice โbut โhas evolved quickly in humans. This study suggests HAR123 plays a crucial role in human brain โฃdevelopment by regulating theโ production of neuronal progenitor cells (NPCs) – the cells that become both neurons and glial cells.
Keyโ Findings:
Neuron-Glia Balance: HAR123 coordinates theโ ratio between neurons and glial cells. This balanceโ is vital for โคbrain development, synapse function, and neuroplasticity (our ability to learn).
Cognitive flexibility: Researchers believe HAR123 may contribute to โ cognitive flexibility – the ability to โคlearn and adapt existing knowledge.
* Potential Link to neurologicalโข Disorders: Imbalances in neuron-glia ratios โคare implicated in conditions like autism, schizophrenia, Alzheimer’s, and Parkinson’s, suggesting โคHAR123 could be โคinvolved โin โฃthese diseases.
Future Research:
Further investigation isโข needed โฃto fully understand HAR123’s molecular effectsโ and determine if the โhumanโ version confers unique neuronal properties. This research could ultimately lead to a better understanding of the molecular basis of neurological developmental โฃdisorders.