状异构菌口腔板的形态发生和牙的进化起源
Madleen Grohganz1, Zerina Johanson2, Joseph N Keating1
1Palaeobiology Research Group, School of Earth Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK.
Royal Society open science
|December 19, 2024
概括
在没有的脊椎动物中,类似牙的结构是独立于真牙的进化. 对异种虫牙的分析表明,它们的发育并不与虫牙相同,支持了异种虫牙的发展.
科学领域:
- 古生物学的古生物学
- 脊椎动物的进化 脊椎动物的进化
- 发展生物学 发展生物学
背景情况:
- 牙是一种定义脊椎动物的创新,通常与脊椎动物 (gnathostomes) 的进化有关.
- 没有下的脊椎动物 (茎型脊椎动物),如异构动物,在它们的口腔板上拥有牙状结构 (牙和结核).
研究的目的:
- 分析异构菌的牙和口腔板的组织学和形态发生.
- 为了测试这些结构与口腔骨架和牙的同质性.
- 为了研究脊椎动物牙的进化起源.
主要方法:
- 对异构菌牙和口腔板的组织学分析.
- 检查生长模式,包括叶片结构和生长层.
- 对内部牙的分布进行了基因组学一致性测试.
主要成果:
- 异质的口腔板表现出偶发的生长,牙表现出与皮肤骨架的连续生长层.
- 没有证据表明异构的牙中存在类似牙的位置或替换模式,这表明缺乏与牙牙的同质性.
- 内部odontode形成的能力在干-gnathostomes内独立地进化了多次.
结论:
- 异种的牙和结核与皮肤骨架相同,而不是真正的牙.
- 结果支持牙进化的"外在"假设.
- 牙的起源涉及到牙产生的能力在脊椎动物中从外口腔扩散到口腔上皮质.
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