Morphometrics, 3D Imaging, and Craniofacial Development

Abstract

Recent studies have shown how volumetric imaging and morphometrics can add significantly to our understanding of morphogenesis, the developmental basis for variation and the etiology of structural birth defects. On the other hand, the complex questions and diverse imaging data in developmental biology present morphometrics with more complex challenges than applications in virtually any other field. Meeting these challenges is necessary in order to understand the mechanistic basis for variation in complex morphologies. This chapter reviews the methods and theory that enable the application of modern landmark-based morphometrics to developmental biology and craniofacial development, in particular. We discuss the theoretical foundations of morphometrics as applied to development and review the basic approaches to the quantification of morphology. Focusing on geometric morphometrics, we discuss the principal statistical methods for quantifying and comparing morphological variation and covariation structure within and among groups. Finally, we discuss the future directions for morphometrics in developmental biology that will be required for approaches that enable quantitative integration across the genotype-phenotype map.

Angiotensin receptor blockade mediated amelioration of mucopolysaccharidosis type I cardiac and craniofacial pathology

“…3D reconstructions from these scans were then landmarked using a standard set of 54 landmarks (Hallgrimsson et al 2009, 2015; Percival et al 2016). The sample analyzed for craniofacial shape variation consists of IDUA −/− mice (age range of 2–8 months), 49 C57BL/6 J mice along with five untreated and six losartan treated male IDUA −/− juvenile animals from group 4.…”

Dinosaurs, Chameleons, Humans, and Evo‐Devo Path: Linking Étienne Geoffroy's Teratology, Waddington's Homeorhesis, Alberch's Logic of “Monsters,” and Goldschmidt Hopeful “Monsters”

“…The architecture of the limbs and craniofacial complex are homologous across tetrapods and thus are constructed using the same embryonic tools, with differences in gene regulation giving rise to the tremendous diversity observed in nature (Hanken and Hall, , , ; Schneider et al., ; Hall, ; Carroll et al., ). In the following paragraphs, a few examples are presented that highlight morphological diversity in craniofacial and limb development in nature and present one of many phenotypes across the morphospace of limbs and cranium (see Hallgrimsson et al., ) that phenocopy specific human congenital malformations structurally and/or due to the developmental pathways perturbed. As Figure shows, not only are signaling pathways conserved in the construction of body plans (limbs and craniofacial elements), nonhuman species are also susceptible to developmental anomalies that parallel human diseases/syndromes such as midfacial patterning defects and limb reductions, losses, and duplications.…”

Nonlinear gene expression‐phenotype relationships contribute to variation and clefting in the A/WySn mouse

“…The change along this axis produces similar changes to the types of changes used to identify clefting embryos. One weakness of Procrustes Superimposition is that large changes in a few landmarks can be distributed across other regions of the shape (reviewed in Reference ) so the fact that there is a strong association between methylation change and a subset of landmarks implies a strong effect on this specific region.…”