Multiple mutations in the Nav1.4 sodium channel of New Guinean toxic birds provide auto‐resistance to deadly batrachotoxin
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Standard
Multiple mutations in the Nav1.4 sodium channel of New Guinean toxic birds provide auto‐resistance to deadly batrachotoxin. / Bodawatta, Kasun H.; Hu, Haofu; Schalk, Felix; Daniel, Jan Martin; Maiah, Gibson; Koane, Bonny; Iova, Bulisa; Beemelmanns, Christine; Poulsen, Michael; Jønsson, Knud A.
I: Molecular Ecology, Bind 33, Nr. 9, e16878, 2024.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Multiple mutations in the Nav1.4 sodium channel of New Guinean toxic birds provide auto‐resistance to deadly batrachotoxin
AU - Bodawatta, Kasun H.
AU - Hu, Haofu
AU - Schalk, Felix
AU - Daniel, Jan Martin
AU - Maiah, Gibson
AU - Koane, Bonny
AU - Iova, Bulisa
AU - Beemelmanns, Christine
AU - Poulsen, Michael
AU - Jønsson, Knud A.
PY - 2024
Y1 - 2024
N2 - Toxicity has evolved multiple times across the tree of life and serves important functions related to hunting, defence and parasite deterrence. Toxins are produced either in situ by the toxic organism itself or associated symbionts, or acquired through diet. The ability to exploit toxins from external sources requires adaptations that prevent toxic effects on the consumer (autoresistance). Here, we examine genomic adaptations that could facilitate autoresistance to the diet-acquired potent neurotoxic alkaloid batrachotoxin (BTX) in New Guinean toxic birds. Our work documents two new toxic bird species and shows that toxic birds carry multiple mutations in the SCN4A gene that are under positive selection. This gene encodes the most common vertebrate muscle Nav channel (Nav1.4). Molecular docking results indicate that some of the mutations that are present in the pore-forming segment of the Nav channel, where BTX binds, could reduce its binding affinity. These mutations should therefore prevent the continuous opening of the sodium channels that BTX binding elicits, thereby preventing muscle paralysis and ultimately death. Although these mutations are different from those present in Neotropical Phyllobates poison dart frogs, they occur in the same segments of the Nav1.4 channel. Consequently, in addition to uncovering a greater diversity of toxic bird species than previously known, our work provides an intriguing example of molecular-level convergent adaptations allowing frogs and birds to ingest and use the same neurotoxin. This suggests that genetically modified Nav1.4 channels represent a key adaptation to BTX tolerance and exploitation across vertebrates.
AB - Toxicity has evolved multiple times across the tree of life and serves important functions related to hunting, defence and parasite deterrence. Toxins are produced either in situ by the toxic organism itself or associated symbionts, or acquired through diet. The ability to exploit toxins from external sources requires adaptations that prevent toxic effects on the consumer (autoresistance). Here, we examine genomic adaptations that could facilitate autoresistance to the diet-acquired potent neurotoxic alkaloid batrachotoxin (BTX) in New Guinean toxic birds. Our work documents two new toxic bird species and shows that toxic birds carry multiple mutations in the SCN4A gene that are under positive selection. This gene encodes the most common vertebrate muscle Nav channel (Nav1.4). Molecular docking results indicate that some of the mutations that are present in the pore-forming segment of the Nav channel, where BTX binds, could reduce its binding affinity. These mutations should therefore prevent the continuous opening of the sodium channels that BTX binding elicits, thereby preventing muscle paralysis and ultimately death. Although these mutations are different from those present in Neotropical Phyllobates poison dart frogs, they occur in the same segments of the Nav1.4 channel. Consequently, in addition to uncovering a greater diversity of toxic bird species than previously known, our work provides an intriguing example of molecular-level convergent adaptations allowing frogs and birds to ingest and use the same neurotoxin. This suggests that genetically modified Nav1.4 channels represent a key adaptation to BTX tolerance and exploitation across vertebrates.
U2 - 10.1111/mec.16878
DO - 10.1111/mec.16878
M3 - Journal article
C2 - 36779590
VL - 33
JO - Molecular Ecology
JF - Molecular Ecology
SN - 0962-1083
IS - 9
M1 - e16878
ER -
ID: 336360833