Vertebral evolution and ontogenetic allometry: The developmental basis of extreme body shape divergence in microcephalic sea snakes

Emma Sherratt, Felicity J. Coutts, Arne Redsted Rasmussen, Kate L. Sanders

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

Snakes exhibit a diverse array of body shapes despite their characteristically
simplified morphology. The most extreme shape changes along the precloacal axis
are seen in fully aquatic sea snakes (Hydrophiinae): “microcephalic” sea snakes
have tiny heads and dramatically reduced forebody girths that can be less than a
third of the hindbody girth. This morphology has evolved repeatedly in sea snakes
that specialize in hunting eels in burrows, but its developmental basis has not
previously been examined. Here, we infer the developmental mechanisms
underlying body shape changes in sea snakes by examining evolutionary patterns
of changes in vertebral number and postnatal ontogenetic growth. Our results
show that microcephalic species develop their characteristic shape via changes in
both the embryonic and postnatal stages. Ontogenetic changes cause the
hindbodies of microcephalic species to reach greater sizes relative to their
forebodies in adulthood, suggesting heterochronic shifts that may be linked to
homeotic effects (axial regionalization). However, microcephalic species also have
greater numbers of vertebrae, especially in their forebodies, indicating that
somitogenetic effects also contribute to evolutionary changes in body shape. Our
findings highlight sea snakes as an excellent system for studying the development
of segment number and regional identity in the snake precloacal axial skeleton.
OriginalsprogEngelsk
TidsskriftEvolution & Development
Vol/bind2019
Sider (fra-til)1-10
Antal sider10
ISSN1525-142X
DOI
StatusUdgivet - 20 feb. 2019

Emneord

  • axial regionalization, axial skeleton, morphological evolution, ontogenetic allometry, vertebrae

Kunstnerisk udviklingsvirksomhed (KUV)

  • Nej

Citer dette

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title = "Vertebral evolution and ontogenetic allometry: The developmental basis of extreme body shape divergence in microcephalic sea snakes",
abstract = "Snakes exhibit a diverse array of body shapes despite their characteristicallysimplified morphology. The most extreme shape changes along the precloacal axisare seen in fully aquatic sea snakes (Hydrophiinae): “microcephalic” sea snakeshave tiny heads and dramatically reduced forebody girths that can be less than athird of the hindbody girth. This morphology has evolved repeatedly in sea snakesthat specialize in hunting eels in burrows, but its developmental basis has notpreviously been examined. Here, we infer the developmental mechanismsunderlying body shape changes in sea snakes by examining evolutionary patternsof changes in vertebral number and postnatal ontogenetic growth. Our resultsshow that microcephalic species develop their characteristic shape via changes inboth the embryonic and postnatal stages. Ontogenetic changes cause thehindbodies of microcephalic species to reach greater sizes relative to theirforebodies in adulthood, suggesting heterochronic shifts that may be linked tohomeotic effects (axial regionalization). However, microcephalic species also havegreater numbers of vertebrae, especially in their forebodies, indicating thatsomitogenetic effects also contribute to evolutionary changes in body shape. Ourfindings highlight sea snakes as an excellent system for studying the developmentof segment number and regional identity in the snake precloacal axial skeleton.",
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author = "Emma Sherratt and Coutts, {Felicity J.} and {Redsted Rasmussen}, Arne and Sanders, {Kate L.}",
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doi = "https://doi.org/10.1111/ede.12284",
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Vertebral evolution and ontogenetic allometry: The developmental basis of extreme body shape divergence in microcephalic sea snakes. / Sherratt, Emma; Coutts, Felicity J.; Redsted Rasmussen, Arne; Sanders, Kate L.

I: Evolution & Development, Bind 2019, 20.02.2019, s. 1-10.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Vertebral evolution and ontogenetic allometry: The developmental basis of extreme body shape divergence in microcephalic sea snakes

AU - Sherratt, Emma

AU - Coutts, Felicity J.

AU - Redsted Rasmussen, Arne

AU - Sanders, Kate L.

PY - 2019/2/20

Y1 - 2019/2/20

N2 - Snakes exhibit a diverse array of body shapes despite their characteristicallysimplified morphology. The most extreme shape changes along the precloacal axisare seen in fully aquatic sea snakes (Hydrophiinae): “microcephalic” sea snakeshave tiny heads and dramatically reduced forebody girths that can be less than athird of the hindbody girth. This morphology has evolved repeatedly in sea snakesthat specialize in hunting eels in burrows, but its developmental basis has notpreviously been examined. Here, we infer the developmental mechanismsunderlying body shape changes in sea snakes by examining evolutionary patternsof changes in vertebral number and postnatal ontogenetic growth. Our resultsshow that microcephalic species develop their characteristic shape via changes inboth the embryonic and postnatal stages. Ontogenetic changes cause thehindbodies of microcephalic species to reach greater sizes relative to theirforebodies in adulthood, suggesting heterochronic shifts that may be linked tohomeotic effects (axial regionalization). However, microcephalic species also havegreater numbers of vertebrae, especially in their forebodies, indicating thatsomitogenetic effects also contribute to evolutionary changes in body shape. Ourfindings highlight sea snakes as an excellent system for studying the developmentof segment number and regional identity in the snake precloacal axial skeleton.

AB - Snakes exhibit a diverse array of body shapes despite their characteristicallysimplified morphology. The most extreme shape changes along the precloacal axisare seen in fully aquatic sea snakes (Hydrophiinae): “microcephalic” sea snakeshave tiny heads and dramatically reduced forebody girths that can be less than athird of the hindbody girth. This morphology has evolved repeatedly in sea snakesthat specialize in hunting eels in burrows, but its developmental basis has notpreviously been examined. Here, we infer the developmental mechanismsunderlying body shape changes in sea snakes by examining evolutionary patternsof changes in vertebral number and postnatal ontogenetic growth. Our resultsshow that microcephalic species develop their characteristic shape via changes inboth the embryonic and postnatal stages. Ontogenetic changes cause thehindbodies of microcephalic species to reach greater sizes relative to theirforebodies in adulthood, suggesting heterochronic shifts that may be linked tohomeotic effects (axial regionalization). However, microcephalic species also havegreater numbers of vertebrae, especially in their forebodies, indicating thatsomitogenetic effects also contribute to evolutionary changes in body shape. Ourfindings highlight sea snakes as an excellent system for studying the developmentof segment number and regional identity in the snake precloacal axial skeleton.

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JO - Evolution & Development

JF - Evolution & Development

SN - 1525-142X

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