Identifying the homology of the short human pisiform and its lost ossification center
Identifying the homology of the short human pisiform and its lost ossification center
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DOI：
10.1186/s13227-019-0145-2
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发表时间：
2019-11-25
期刊：
影响因子：
4.1
通讯作者：
Reno, Philip L.
中科院分区：
文献类型：
--
作者：
Kjosness, Kelsey M.;Reno, Philip L.
背景：豆状骨和跟骨是腕部和脚踝的平行骨骼，也是哺乳动物中仅有的分别由两个骨化中心和生长板发育而来的腕骨和踝骨。自从我们与黑猩猩和矮黑猩猩共同的祖先以来，人类的豆形和跟骨经历了巨大的进化变化。人类豆状骨被截断，失去了一个骨化中心和相关的生长板，而人类跟骨扩大并保留了两个骨化中心和一个生长板。哺乳动物豆状骨的形态多种多样，但极短的豆状骨很少见，骨化中心的丢失更是罕见。这就提出了一个问题：人类唯一的豌豆状骨化中心是否与其他物种的初级中心或次级中心同源。为了解决这个问题，我们对来自博物馆骨骼收藏的猕猴、猿和人类(n=907)的豆状和跟骨骨化模式和时间进行了个体遗传学研究。结果：人类豆状骨化不规律，在发育过程中缺乏其他灵长类动物的特征。豆状骨的初级和次级中心骨化时间通常与非人灵长类动物的跟骨相匹配，而人类的豆状骨则与跟骨次级中心骨化相对应。结论：这些数据表明，人类豆状骨与其他物种的豌豆状骨骺具有同源性，人类失去了初级骨化中心和相关的生长板，同时保留了次级骨化中心的骨化时机。这代表了一次特殊的进化事件，并展示了人类手腕的深刻发育变化，这不仅在灵长类动物中是不寻常的，在哺乳动物中也是如此。
Background: The pisiform and calcaneus are paralogous bones of the wrist and ankle and are the only carpal and tarsal, respectively, to develop from two ossification centers with an associated growth plate in mammals. Human pisiforms and calcanei have undergone drastic evolutionary changes since our last common ancestor with chimpanzees and bonobos. The human pisiform is truncated and has lost an ossification center with the associated growth plate, while the human calcaneus has expanded and retained two ossification centers and a growth plate. Mammalian pisiforms represent a wide range of morphologies but extremely short pisiforms are rare and ossification center loss is even rarer. This raises the question of whether the sole human pisiform ossification center is homologous to the primary center or the secondary center of other species. We performed an ontogenetic study of pisiform and calcaneus ossification patterns and timing in macaques, apes, and humans (n = 907) from museum skeletal collections to address this question.Results: Human pisiforms ossify irregularly and lack characteristic features of other primates while they develop. Pisiform primary and secondary center ossification timing typically matches that of the calcaneus of non-human primates, while the human pisiform corresponds with calcaneal secondary center ossification. Finally, human pisiforms ossify at the same dental stages as pisiform and calcaneal secondary centers in other hominoids.Conclusions: These data indicate that the human pisiform is homologous to the pisiform epiphysis of other species, and that humans have lost a primary ossification center and associated growth plate while retaining ossification timing of the secondary center. This represents an exceptional evolutionary event and demonstrates a profound developmental change in the human wrist that is unusual not only among primates, but among mammals.