Table 3.

Summary of genes associated with vertebral traits and bone development in sheep.

Genes	Associated Traits	Breeds	Country	Reference
NR6A1	✧Variation in the number of lumbar spine segments	Xinjiang Kazakh sheep	China	[56]
SFRP4	✧It plays a role in bone development and is associated with the presence of multiple lumbar vertebrae	Duolang sheep		[57]
SYNDIG1L, UNC13C	✧Influence the number of thoracic vertebrae	Han sheep and Sunite sheep		[52]
TBXT	✧Associated with the determination of caudal vertebrae number and tail length	Sheep		[58]
MGAT4A, KCNH1 CPOX, CPQ	✧Play a role in determining the number of ribs in vertebrates	Hu sheep		[59]
LTBP2, SYNDIG1L	✧Associated with the number of both ribs and vertebrae in vertebrates	Large fat-tailed sheep, Altay sheep, Tibetan sheep		[60]
VRTN, HoxA	✧Linked with vertebral development and associated with the presence of thoracic vertebrae. They also play a role in regulating spinal development and morphology.	Xinjiang Kazakh sheep		[61]
NDRG2	✧Associated with the development of the spine and provides valuable genetic resources for studying the transcriptome of various vertebral traits	Kazakh sheep		[62]
VRTN	✧Correlated with thoracic vertebral number, carcass length, and carcass weight in vertebrates	China Kazakh sheep		[55]
NID2, ACAN	✧Involved in skeletal development and the maintenance of cartilage structure	Afghani sheep	Iran	[63]
ALX4, HOXB13, BMP4 EYA2, SULF2	✧Involved in the embryonic development of tendons, bones, and cartilage as well as the development of limbs, the skeleton, and tail formation	Ethiopian indigenous sheep	Ethiopia	[64]