TY - JOUR
T1 - Plicidentine and the repeated origins of snake venom fangs
AU - Palci, Alessandro
AU - Leblanc, Aaron R.H.
AU - Panagiotopoulou, Olga
AU - Cleuren, Silke G.C.
AU - Mehari Abraha, Hyab
AU - Hutchinson, Mark N.
AU - Evans, Alistair R.
AU - Caldwell, Michael W.
AU - Lee, Michael S.Y.
PY - 2021/8/11
Y1 - 2021/8/11
N2 - Snake fangs are an iconic exemplar of a complex adaptation, but despite striking developmental and morphological similarities, they probably evolved independently in several lineages of venomous snakes. How snakes could, uniquely among vertebrates, repeatedly evolve their complex venom delivery apparatus is an intriguing question. Here we shed light on the repeated evolution of snake venom fangs using histology, high-resolution computed tomography (microCT) and biomechanical modelling. Our examination of venomous and non-venomous species reveals that most snakes have dentine infoldings at the bases of their teeth, known as plicidentine, and that in venomous species, one of these infoldings was repurposed to form a longitudinal groove for venom delivery. Like plicidentine, venom grooves originate from infoldings of the developing dental epithelium prior to the formation of the tooth hard tissues. Derivation of the venom groove from a large plicidentine fold that develops early in tooth ontogeny reveals how snake venom fangs could originate repeatedly through the co-option of a pre-existing dental feature even without close association to a venom duct. We also show that, contrary to previous assumptions, dentine infoldings do not improve compression or bending resistance of snake teeth during biting; plicidentine may instead have a role in tooth attachment.
AB - Snake fangs are an iconic exemplar of a complex adaptation, but despite striking developmental and morphological similarities, they probably evolved independently in several lineages of venomous snakes. How snakes could, uniquely among vertebrates, repeatedly evolve their complex venom delivery apparatus is an intriguing question. Here we shed light on the repeated evolution of snake venom fangs using histology, high-resolution computed tomography (microCT) and biomechanical modelling. Our examination of venomous and non-venomous species reveals that most snakes have dentine infoldings at the bases of their teeth, known as plicidentine, and that in venomous species, one of these infoldings was repurposed to form a longitudinal groove for venom delivery. Like plicidentine, venom grooves originate from infoldings of the developing dental epithelium prior to the formation of the tooth hard tissues. Derivation of the venom groove from a large plicidentine fold that develops early in tooth ontogeny reveals how snake venom fangs could originate repeatedly through the co-option of a pre-existing dental feature even without close association to a venom duct. We also show that, contrary to previous assumptions, dentine infoldings do not improve compression or bending resistance of snake teeth during biting; plicidentine may instead have a role in tooth attachment.
KW - Colubroidea
KW - development
KW - fangs
KW - Ophidia
KW - Serpentes
KW - venom groove
UR - http://www.scopus.com/inward/record.url?scp=85113317073&partnerID=8YFLogxK
UR - http://purl.org/au-research/grants/ARC/DP200102328
U2 - 10.1098/rspb.2021.1391
DO - 10.1098/rspb.2021.1391
M3 - Article
C2 - 34375553
AN - SCOPUS:85113317073
VL - 288
JO - Proceedings of The Royal Society of London Series B: Biological Sciences
JF - Proceedings of The Royal Society of London Series B: Biological Sciences
SN - 0962-8452
IS - 1956
M1 - 20211391
ER -