|Liu, Hsiao Ching|
Submitted to: Animal Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 9, 2002
Publication Date: April 1, 2003
Citation: Liu, H., Cheng, H.H. 2003. Genetic mapping of the chicken stem cell antigen 2 (SCA2) gene to chromosome 2 via PCR primer mutagenesis. Animal Genetics. 34:146-160. Interpretive Summary: Marek's disease is the most severe chronic disease problem facing the poultry industry. To overcome this problem, it is desirable to select for chickens with superior Marek's disease resistance. For this goal to become a reality, we need to identify genes that confer resistance to Marek's disease, especially in regions that we have found to confer disease resistance. In this paper, we map a gene called SCA2, which is likely to be involved in Marek's disease resistance. Using a novel assay, we could readily place SCA2 onto the chicken genetic map and in relationship to 14 important genetic regions that were previously identified. Thus, our results indicate that further experiments are required to determine if SCA2 can be used to select elite chickens. Furthermore, we have developed an assay that will allow for the selection of specific SCA2 alleles in chickens. The information is valuable to scientists working on improving genetic resistance to Marek's and should improve our ability to control this important disease of chickens.
Technical Abstract: SCA2 (also called thymic shared antigen 1, TSA1) is a cell membrane protein involved in T cell differentiation, and shares homology to the LY6 multigene family. The chicken SCA2 gene was identified in two separate DNA microarray experiments. First, SCA2 was up regulated in chicken embryo fibroblast (CEF) cells following Marek¹s disease virus (MDV) infection. And second, SCA2 in lymphocytes was differentially expressed between Marek¹s disease(MD) resistant and susceptible inbred lines following MDV challenge. To determine if SCA2 lies in a previously mapped MD QTL region, polymerase chain reaction (PCR) primers were used to amplify the 3¹ untranslated region (UTR) of the chicken SCA2 gene. Two SNPs were identified and a PCR-RFLP genotyping assay developed, which enabled the placement of SCA2 on chromosome 2 in a region that was not previously surveyed in our QTL scans.