Geometric morphometrics of face profile across horse breeds and within Arabian horses.

Autor: Alhaddad H; Department of Biological Sciences, Kuwait University, Shadadiya, Kuwait. Electronic address: hassan.alhaddad@ku.edu.kw., Powell BB; Department of Animal Science, UF Genetics Institute, University of Florida, Gainesville, Florida, USA., Pinto LD; Biology Department, La Sierra University, Riverside, California, USA., Sutter N; Biology Department, La Sierra University, Riverside, California, USA., Brooks SA; Department of Animal Science, UF Genetics Institute, University of Florida, Gainesville, Florida, USA., Alhajeri BH; Department of Biological Sciences, Kuwait University, Shadadiya, Kuwait.
Jazyk: angličtina
Zdroj: Journal of equine veterinary science [J Equine Vet Sci] 2024 Jan; Vol. 132, pp. 104980. Date of Electronic Publication: 2023 Dec 08.
DOI: 10.1016/j.jevs.2023.104980
Abstrakt: Horse traits under selection are largely quantitative and affected by multiple genes. Horse face shape is an example of a continuous trait, which due to the reliance on observational assessments, is classified into; "dished", "straight", and "roman-nosed". This categorization is often inadequate to convey the full spectrum of the face shape variation especially for genetic studies. The first objective of the current study was to use geometric morphometric methods to quantitatively phenotype face shapes and examine its variation across horse breeds. The second objective was to analyze the face shape variation within Arabian horses since face shape is (1) favored, valued, and genetically selected in certain lineages (e.g. Egyptian), (2) is evaluated by registries and scored in shows, and (3) in its extreme forms pose health concerns. We digitized landmarks on lateral profile photos, particularly on the dorsal curvature of the rostrum, and subjected these landmarks to Generalized Procrustes Analysis to generate independent shape and size variables which were statistically compared across breeds and within Arabians. Horse breeds varied in nasal curvature, ranging from extremely concave to extremely convex, with over 70 % of horse breeds exhibiting intermediate concavity (i.e., straight profile). Interestingly, Arabian horses possessed the highest diversity in face profile and individuals clustered into three distinct shape sub-groups (one dished and two straight profile clusters). Our quantitative phenotyping method can be the basis of future genetic studies of facial profile within Arabian lineages as a favored traits and potentially manage its extreme forms as a likely genetic disease.
Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest.
(Copyright © 2023 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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