Genetic connection and phenotypic analysis of sec23b insersional mutants in green alg Chlamydomonas reinhardtii

In all eukaryotic organisms, protein trafficking is required to maintain homeostasis. The secretory pathway is responsible for the synthesis, folding and delivery of a wide variety of cellular proteins to the required target regions. All secreted proteins newly synthesized in the secretory pathway are transported from the endoplasmic reticulum (ER) to Golgi before being delivered to their final destination. The SEC23B gene, which is found in the Chlamydomonas reinhardtii genome, in many living beings and model organisms, is a gene that carries secretory proteins from the (ER) to the Golgi apparatus and is involved in the formation of vesicles of the layer protein complex II (COPII). In the thesis study, the characterization of the SEC23B insertional mutant was done. PCR was done for detection of insertion in the genome of sec23b mutant, RT-PCR was done to detect mRNA levels, progeny test was done for genetic linkage analysis. Also for phenotypic analysis; enzyme activity, cell count and zygote formation tests were performed. Enzyme activity tests were performed to determine whether there is secretion function in the sec23b mutant and arylsulfatase, phosphatase activities were examined. The study was aimed to determine whether there is any disruption in the trafficking within the cell as a result of the mutation of the SEC23B gene. According to the tetrad analysis results, especially change in color and morphological differences were observed which draw attention. The lack of previous study on this subject in the literature indicates that more molecular studies are needed.