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Analysis of Craniofacial Variation in cleft secondary palate‐1 Heterozygous and Homozygous Newborn Mice
Author(s) -
Bennett Holly,
Moskal Russell,
Holloway Jared,
Jones Jennifer,
Holton Nathan,
Leslie Erin,
Bjork Bryan
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.743.4
Subject(s) - congenic , craniofacial , anatomy , biology , nasal bone , genetics , gene
Prdm16 is involved in normal human and mouse craniofacial development. The cleft secondary palate 1 ( csp1 ) ENU‐induced mutation displays cleft palate, shortening of the snout, and micrognathia on a congenic FVB/NJ strain background due to reduced Prdm16 expression, which mirrors the mechanism of Pierre Robin Sequence (PRS) in human. However, overt cleft palate is not evident on a congenic C57BL6/J background ( csp1‐B6 ). Adult heterozygous csp1‐B6 mice have significantly shortened snouts, palates, and right‐side mandibles compared to wt littermates along with variable incidence of malocclusion and hydrocephalus. Homozygous mutant csp1‐B6 mice die shortly after birth for unknown reasons. Our aim is to quantitatively assess variation in bony facial morphology in newborn heterozygous (het) and homozygous mutant (mut) csp1‐B6 and contrast this with the wild type morphology. We compared the size, shape, and volume of the facial bones in newborn wt, het, and mut csp1‐B6 mice. Anatomical landmarks, bone surface area, and bone volume data were collected from three‐dimensional microcomputed tomography (microCT) images. Homozygous mutant newborn mice have significantly longer left‐sided premaxillae and maxillae, but shorter left‐side mandibles than the wt and het mice. The mut mice also showed significantly reduced left‐ and right‐side premaxillae heights versus wt and het mice and smaller individual facial bone volumes and surface areas. The wt and het newborn mice did not differ significantly from each other in any contrasts. Reduced Prdm16 expression in newborn homozygous mutant csp1‐B6 mice is correlated with overall, and asymmetric, micrognathia and undergrowth of the snout compared to the newborn wt and het mice. These findings complement our concurrent research on adult heterozygous csp1‐B6 mice, and will provide insight on the downstream effects of Prdm16 expression on craniofacial development and integration among the bones of the face. Support or Funding Information NIH/NIDCR (R15DE023982)Midwestern University, College of Dental Medicine Illinois Intramural Research Grant