Postnatal Craniofacial Skeletal Development of Female C57BL/6NCrl Mice

Abstract

The craniofacial skeleton is a complex and unique structure. The perturbation of its development can lead to craniofacial dysmorphology and associated morbidities. Our ability to prevent or mitigate craniofacial skeletal anomalies is at least partly dependent on our understanding of the unique physiological development of the craniofacial skeleton. Mouse models are critical tools for the study of craniofacial developmental abnormalities. However, there is a lack of detailed normative data of mouse craniofacial skeletal development in the literature. In this report, we employed high-resolution micro-computed tomography (μCT) in combination with morphometric measurements to analyze the postnatal craniofacial skeletal development from day 7 (P7) through day 390 (P390) of female C57BL/6NCrl mice, a widely used mouse strain. Our data demonstrates a unique craniofacial skeletal development pattern in female C57BL/6NCrl mice, and differentiates the early vs. late craniofacial growth patterns. Additionally, our data documents the complex and differential changes in bone parameters (thickness, bone volume, bone volume/tissue volume, bone mineral density, and tissue mineral density) of various craniofacial bones with different embryonic origins and ossification mechanisms during postnatal growth, which underscores the complexity of craniofacial bone development and provides a reference standard for future quantitative analysis of craniofacial bones.

A Ciliary Protein EVC2/LIMBIN Plays a Critical Role in the Skull Base for Mid-Facial Development

“…Furthermore, in both types of Evc2 cKO, at P8 and P28, we observed insignificant gender-specific differences (Supplementary Table S1 ), particularly in the parameters characterizing mid-facial defects. Lack of gender-specific observations is consistent with previous studies and we, therefore, did not match genders in our comparative analyses ( Vora et al, 2015 ; Wei et al, 2017 ). Therefore, we combined both genders for the rest of our comparisons.…”

In situ measurement of the isoplanatic patch for imaging through intact bone

“…This age range was selected because they have relatively thinner skulls than adult mouse, which is a suitable choice for imaging inside or through their skull. This age range is particularly interesting for imaging, because the neurogenesis in the cortical layers peak in P12-P17 [7], but bone maturation has not peaked yet [6], which makes it suitable for neuroimaging, as well as bone and developmental research.…”

“…Therefore, the layers of collagenous fibers and mineralization create a multiple-scattering [3][4][5] regime for light propagation even in relatively thin juvenile cranial bone, although at a smaller scale. The juvenile age range was selected because the mouse skull is still in development, and due to it being less mineralized and thinner [6] it shows a larger isoplanatic patch (IP). However since neurogenesis in cortical layers peaks at 11-17 days postnatally [7], this age group can be used in neuroimaging, as well as bone and developmental biology research.…”

Mid-facial developmental defects caused by the widely used LacZ reporter gene when expressed in neural crest-derived cells

“…Skulls were measured by using Micro-CT (eXplore Locus SP, GE Healthcare Pre-Clinical Imaging, London, ON, Canada) and digital caliper (Fowler 6"/150 mm Ultra-Cal V, Sylvac SA) as previously described (Wei et al 2017). Micro-CT images were reoriented and reconstructed to 3D through Microview (version 2.2).…”