ORIGINAL RESEARCH article
Front. Vet. Sci.
Sec. Livestock Genomics
This article is part of the Research TopicGenomic Selection and Evolution in Domestic AnimalsView all 7 articles
Genome-Wide Selection Analysis Identifies Genes Associated with Mandibular Defects in Duolang Sheep
Provisionally accepted
- Xinjiang Agricultural University, Urumqi, China
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
Brachycephaly is characterized by a conspicuously shortened craniofacial structure. While it is a defining trait in certain species such as Bulldogs, Persian cats, Niata cattle, Anglo-Nubian goats, and Middle White pigs, it may also represent a pathological condition. In Duolang sheep, brachycephaly is strikingly pronounced and may arise from distinct genetic and developmental mechanisms linked to breed history. This condition, often accompanied by mandibular prognathism, predisposes affected animals to health problems including brachycephalic airway obstruction syndrome, nasal blockage with dyspnea, and feeding difficulties. Duolang sheep, a dominant indigenous breed in southern Xinjiang, China, comprise approximately two million individuals, nearly 10% of which exhibit this heritable defect. Such a high prevalence poses a significant challenge to genetic improvement programs in local populations. Elucidating the genetic basis of this phenotype and identifying candidate genes is therefore essential. To characterize the craniofacial phenotype, we obtained X-ray measurements of maxillary length, mandibular length, and incisor angle. Affected sheep displayed significantly shorter maxillae and longer mandibles compared with controls (P < 0.05), whereas incisor angle showed no significant difference. Here, we performed whole-genome resequencing of two phenotypically distinct Duolang sheep cohorts and analyzed genomic architecture and variation patterns using a selective sweep approach. Candidate regions under strong selection were identified by Fst and π-ratio analyses. Gene annotation revealed functionally relevant candidates associated with skeletal growth and development (MTX2, FGF12, IGF, PPARGC1A, LIPC, LY86, and IL33). These findings provide new insights into the genetic basis of brachycephaly in Duolang sheep and offer strategies for genetic improvement, contributing to broader research on skeletal development and growth regulation in livestock.
Keywords: Candidategenes, Duolang sheep, Fst, Mandibular prognathism, nucleotide diversity (π)
Received: 28 Sep 2025; Accepted: 09 Dec 2025.
Copyright: © 2025 Cao, Chen, Liu and Wujun. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence:
Lingling Liu
Liu Wujun
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.