New genomic and fossil data illuminate the origin of enamel

Qu, Qingming; Haitina, Tatjana; Zhu, Min; Ahlberg, Per

doi:10.1038/nature15259

Cited by 78 publications

(88 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(2) Psarolepis scale Psarolepis romeri, found in the Late Silurian to Early Devonian deposits from South China, was first considered as either a stem sarcopterygian or a stem osteichthyan (Zhu, Yu & Janvier, 1999;Zhu & Schultze, 2001;Qu et al, 2015b), but has been iteratively resolved as a stem sarcopterygian in recent phylogenetic analysis (Friedman, 2007;Zhu et al, , 2013Davis, Finarelli & Coates, 2012;Dupret et al, 2014). Only disarticulated fossils such as lower jaws, skulls, shoulder girdles, fin spines and scales have been found so far (Yu, 1998;Zhu et al, 1999Zhu et al, , 2012Zhu & Yu, 2004, 2009.…”

Section: (1) Andreolepis Scalementioning

confidence: 98%

The origin of novel features by changes in developmental mechanisms: ontogeny and three‐dimensional microanatomy of polyodontode scales of two early osteichthyans

Sanchez

Zhu

et al. 2016

Biological Reviews

Self Cite

View full text Add to dashboard Cite

Recent advances in synchrotron imaging allow us to study the three-dimensional (3D) histology of vertebrate fossils, including microfossils (e.g. teeth and scales) of early jawed vertebrates. These microfossils can often be scanned at submicron resolution (<1 µm) because of their small size. The resulting voxel (3D pixel) stacks can be processed into virtual thin sections revealing almost every internal detail of the samples, comparable to traditional thin sections. In addition, 3D models of the internal microanatomical structures, such as embedded odontodes and vasculature, can be assembled and examined in situ. Scales of two early osteichthyans, Psarolepis romeri from the Early Devonian of China and Andreolepis hedei from the Late Silurian of Sweden, were scanned using propagation phase-contrast synchrotron X-ray microtomography (PPC-SRµCT), and 3D models of internal canal systems and buried odontodes were created from the scans. Based on these new data, we review the evolutionary origin of cosmine and its associated pore-canal system, which has been long recognized as a synapomorphy of sarcopterygians. The first odontode that appeared during growth shows almost identical morphology in the two scales, but the second odontode of the Psarolepis scale shows a distinctive morphology with several pores on the surface. It is suggested that a shift from ridge-like odontode to pore-bearing odontode was the key step in the origin of cosmine, which was then elaborated further in more-derived sarcopterygians. We perform a detailed comparison between the two scales and propose a primary homology framework to generate microanatomical characters, which can be used in the phylogenetic analysis of early osteichthyans when more 3D data become available. Our results highlight the importance of 3D data for the study of histology and ontogeny of the dermal skeleton of early jawed vertebrates, especially scales of the polyodontode type. The traditional microvertebrate collection is not only useful for biostratigraphic studies, but also preserves invaluable biological information about the growth of vertebrate hard tissues. Today, we are only beginning to understand the biological meaning of the new 3D data. The increasing availability of such data will enable, and indeed require, a complete revision of traditional palaeohistological studies on early vertebrates.

show abstract

Section: (1) Andreolepis Scalementioning

confidence: 98%

The origin of novel features by changes in developmental mechanisms: ontogeny and three‐dimensional microanatomy of polyodontode scales of two early osteichthyans

Sanchez

Zhu

et al. 2016

Biological Reviews

Self Cite

View full text Add to dashboard Cite

show abstract

“…66 However, no mutations of AMBN have previously been associated with dentin defects. In this report, we found that the genetic change of AMBN leads to dentin disorders.…”

Section: Discussionmentioning

confidence: 99%

Whole exome sequencing identifies an AMBN missense mutation causing severe autosomal-dominant amelogenesis imperfecta and dentin disorders

Lü

et al. 2018

Int J Oral Sci

View full text Add to dashboard Cite

Tooth development is a complex process that involves precise and time-dependent orchestration of multiple genetic, molecular, and cellular interactions. Ameloblastin (AMBN, also named “amelin” or “sheathlin”) is the second most abundant enamel matrix protein known to have a key role in amelogenesis. Amelogenesis imperfecta (AI [MIM: 104500]) refers to a genetically and phenotypically heterogeneous group of conditions characterized by inherited developmental enamel defects. The hereditary dentin disorders comprise a variety of autosomal-dominant genetic symptoms characterized by abnormal dentin structure affecting either the primary or both the primary and secondary teeth. The vital role of Ambn in amelogenesis has been confirmed experimentally using mouse models. Only two cases have been reported of mutations of AMBN associated with non-syndromic human AI. However, no AMBN missense mutations have been reported to be associated with both human AI and dentin disorders. We recruited one kindred with autosomal-dominant amelogenesis imperfecta (ADAI) and dentinogenesis imperfecta/dysplasia characterized by generalized severe enamel and dentin defects. Whole exome sequencing of the proband identified a novel heterozygous C-T point mutation at nucleotide position 1069 of the AMBN gene, causing a Pro to Ser mutation at the conserved amino acid position 357 of the protein. Exfoliated third molar teeth from the affected family members were found to have enamel and dentin of lower mineral density than control teeth, with thinner and easily fractured enamel, short and thick roots, and pulp obliteration. This study demonstrates, for the first time, that an AMBN missense mutation causes non-syndromic human AI and dentin disorders.

show abstract

“…Lophosteus is currently considered by some to be a stem-osteichthyan (Botella et al, 2007; Cunningham et al, 2012), but it has also been proposed as sharing affinities with crown osteichthyans (Gross, 1971; Rohon, 1893), acanthodians (Schultze & Märss, 2004), and placoderms (Burrow, 1995). The view that Lophosteus is the least crownward stem-osteichthyan (Botella et al, 2007) has a significant impact on interpreting gnathostome phylogeny and the acquisition of crown gnathostome characteristics (Brazeau, 2009; Brazeau & Friedman, 2014; Giles, Friedman & Brazeau, 2015; Qu et al, 2015b). …”

Section: Introductionmentioning

confidence: 99%

Three-dimensional paleohistology of the scale and median fin spine ofLophosteus superbus(Pander 1856)

Jerve

Sanchez

et al. 2016

PeerJ

Self Cite

View full text Add to dashboard Cite

Lophosteus superbus is one of only a handful of probable stem-group osteichthyans known from the fossil record. First collected and described in the late 19th century from the upper Silurian Saaremaa Cliff locality in Estonia, it is known from a wealth of disarticulated scales, fin spines, and bone fragments. In this study we provide the first description of the morphology and paleohistology of a fin spine and scale from Lophosteus using virtual thin sections and 3D reconstructions that were segmented using phase-contrast synchrotron X-ray microtomography. These data reveal that both structures have fully or partially buried odontodes, which retain fine morphological details in older generations, including sharp nodes and serrated ridgelets. The vascular architecture of the fin spine tip, which is composed of several layers of longitudinally directed bone vascular canals, is much more complex compared to the bulbous horizontal canals within the scale, but they both have distinctive networks of ascending canals within each individual odontode. Other histological characteristics that can be observed from the data are cell spaces and Sharpey’s fibers that, when combined with the vascularization, could help to provide insights into the growth of the structure. The 3D data of the scales from Lophosteus superbus is similar to comparable data from other fossil osteichthyans, and the morphology of the reconstructed buried odontodes from this species is identical to scale material of Lophosteus ohesaarensis, casting doubt on the validity of that species. The 3D data presented in this paper is the first for fossil fin spines and so comparable data is not yet available. However, the overall morphology and histology seems to be similar to the structure of placoderm dermal plates. The 3D datasets presented here provide show that microtomography is a powerful tool for investigating the three-dimensional microstructure of fossils, which is difficult to study using traditional histological methods. These results also increase the utility of fin spines and scales suggest that these data are a potentially rich source of morphological data that could be used for studying questions relating to early vertebrate growth and evolution.

show abstract

New genomic and fossil data illuminate the origin of enamel

Cited by 78 publications

References 32 publications

The origin of novel features by changes in developmental mechanisms: ontogeny and three‐dimensional microanatomy of polyodontode scales of two early osteichthyans

The origin of novel features by changes in developmental mechanisms: ontogeny and three‐dimensional microanatomy of polyodontode scales of two early osteichthyans

Whole exome sequencing identifies an AMBN missense mutation causing severe autosomal-dominant amelogenesis imperfecta and dentin disorders

Three-dimensional paleohistology of the scale and median fin spine ofLophosteus superbus(Pander 1856)

Contact Info

Product

Resources

About