Genetic linkage and phenotypic analyses of COPII vesiclesubunit SEC24A insertion mutants in Chlamydomonas reinhardtii

Chlamydomonas reinhardtii, a unicellular microalga was used as model organism in this study. A forward genetic analysis was done using an insertional mutant sec24a which had an insertion in 3'UTR region. COPII complex is made of 5 different proteins. These proteins are GTPase Sar1, SEC23/SEC24 complex SEC13/SEC31 complex. SEC24 is involved in cargo recognition and study was done on SEC24A paralog of C. reinhardtii which has two SEC24 paralogs. Bioinformatic analysis has shown that SEC24A is most similar to human SEC24D and it contains the FXP motif which is involved in binding to SEC23. sec24a didn't have any detectable abnormalities in gametogenesis, zygote formation and meiosis. sec24a had normal arylsulfatase activity but alkaline phosphatase activity may be lower according to our colorimetric assays. Third backcross of the mutant needs to be generated in order to make a conclution on this phenotype.