Details

Autor(en) / Beteiligte

• Toussaint, Nicolas
• Redhead, Yushi
• Vidal-García, Marta
• Lo Vercio, Lucas
• Liu, Wei
• Fisher, Elizabeth M C
• Hallgrímsson, Benedikt
• Tybulewicz, Victor L J
• Schnabel, Julia A
• Green, Jeremy B A

Titel

A landmark-free morphometrics pipeline for high-resolution phenotyping: application to a mouse model of Down syndrome

Ist Teil von

• Development (Cambridge), 2021-03, Vol.148 (18)

Ort / Verlag

England: The Company of Biologists Ltd

Erscheinungsjahr

2021

Quelle

MEDLINE

Beschreibungen/Notizen

• Characterising phenotypes often requires quantification of anatomical shape. Quantitative shape comparison (morphometrics) traditionally uses manually located landmarks and is limited by landmark number and operator accuracy. Here, we apply a landmark-free method to characterise the craniofacial skeletal phenotype of the Dp1Tyb mouse model of Down syndrome and a population of the Diversity Outbred (DO) mouse model, comparing it with a landmark-based approach. We identified cranial dysmorphologies in Dp1Tyb mice, especially smaller size and brachycephaly (front-back shortening), homologous to the human phenotype. Shape variation in the DO mice was partly attributable to allometry (size-dependent shape variation) and sexual dimorphism. The landmark-free method performed as well as, or better than, the landmark-based method but was less labour-intensive, required less user training and, uniquely, enabled fine mapping of local differences as planar expansion or shrinkage. Its higher resolution pinpointed reductions in interior mid-snout structures and occipital bones in both the models that were not otherwise apparent. We propose that this landmark-free pipeline could make morphometrics widely accessible beyond its traditional niches in zoology and palaeontology, especially in characterising developmental mutant phenotypes.