Search for Association between Ovine Wingless-Type MMTV Integration Site Family Member (Wnt10A) Genes with Supernumerary Teat in Ghezel and Romanov Sheep

Supernumerary teats (SNT, polythelia) is a common abnormality in many mammalian species including sheep. Recently, the WNT10A candidate gene has been reported to be associated with regulation of embry-onic programming for mammary gland connective tissue differentiation and embryogenesis. Here, we pro-pose that variants of this candidate gene may be linked with SNT in Ghezel (GHE) and Romanov (ROM) sheep. Therefore, a case-control study was conducted to uncover this abnormal phenotype. The study group consisted of fifteen individuals which had four functional teats (GHE=10, ROM=5). The control group con-sisted of thirty individuals which each had two (normal) teats (GHE=20, ROM=10). After extraction of genomic DNA from all samples, the candidate gene region was amplified using routine PCR. Genotyping at the WNT10A gene was performed by sequencing of the purified amplicons. Genotypes and allele frequen-cies were compared between the two study groups using the χ2 statistical test. A P-value of 0.05 was con-sidered to be the threshold below which all results were significant. No effect of allelic variation (A/G in exon 4) between case and control groups in GHE and ROM sheep was found. In summary, our study pro-vides preliminary results linking candidate gene this single nucleotide polymorphism to SNT in GHE and ROM sheep.