A recent study conducted by researchers at Penn State has shed new light on the evolutionary history of key proteins essential for electrical signaling in the nervous system. The study reveals that certain ion channels existed before the earliest common ancestor of animals, rewriting the conventionally understood evolutionary history.
The research focused on the Shaker family of potassium ion channels, which are found in a wide range of animals from humans to fruit flies. Previous studies suggested that these ion channels arose and diversified alongside the evolution of the nervous system. However, this new study found evidence of Shaker family genes in microscopic single-celled organisms called choanoflagellates, long before the origin of the nervous system.
The researchers expanded their search to 21 choanoflagellate species and found evidence of Shaker family genes in three of these species. This finding suggests that multiple subtypes were present at the base of the animal family tree, including Kv1, which are found in comb jellies, and the Kv2-4-like channels, which are found in choanoflagellates.
The study’s lead author, Timothy Jegla, noted that this discovery adds to growing evidence that many elements of the nervous system were present before the nervous system as a whole evolved. “Most of the functionally important proteins that we use in electrical signaling, which underlie neuronal communication and neuromuscular movement, are all based on proteins that existed before animals,” Jegla said.
This research has significant implications for our understanding of evolution and may have implications for the treatment of disorders related to ion channel dysfunction, such as heart arrhythmias and epilepsy.
Source: https://scitechdaily.com/study-challenges-evolutionary-timeline-nervous-system-building-blocks-found-in-ancient-single-celled-organisms/