Are the two polymorphic sites of anti-Marek’s disease in White Leghorn chickens also suitable for Partridge Shank chickens?

Background: The selection of Marek’s disease (MD)-resistant breeds in Partridge Shank chicken, a popular local chicken breed in Henan Province of China, has practical value. We hypothesized that the two polymorphic sites (rs14527240 located in SMOC1 and GGaluGA156129 located in PTPN3) related to MD resistance in White Leghorn chickens are also applicable to Partridge Shank chickens. Methods: In this experiment, we screened 10 live hens and 2 live roosters with the double GG genotype by genotyping the two sites from 6500 Partridge Shank chickens. Nineteen one-day-old chicks with the double GG genotype were obtained by artificial insemination. Seventy-two one-day-old chickens (19 from the population expansion test and 53 randomly selected from chicken farms) were injected with 2000 plaque-forming units of the Md5 virus strain. After 100 days of infection, all chickens were examined by pathological anatomical examination, histological sectioning, genotyping, and a quantitative polymerase chain reaction of SMOC1 and PTPN3. Results: There was only one site (rs14527240 located in SMOC1) associated with MD in Partridge Shank chickens (p < 0.05), but the GG genotype of SMOC1 in Partridge Shank chickens indicated susceptibility to MD. SMOC1 expression in MD-susceptible chickens was also significantly higher than that in MD-resistant chickens (p < 0.05). Conclusion: Therefore, the MD resistance sites selected from White Leghorn chickens were not completely suitable for Partridge Shank chickens, but they can be used as a reference. This study indicated that SMOC1 plays an important role in screening for MD resistance in poultry.