Caulerpa cylindracea türünde alternatif oksidaz kodlayan genlerin tanımlanması

Alternative oxidases (AOX) are involved in adaptation of organisms to different environmental conditions. Function of mitochondrial AOX proteins have been described for electron flow through electron transport chain and regulation of mitochondrial retrograde signaling pathway. The roles of AOX proteins have been found in sexual reproduction, vegetative reproduction, and resistance against oxidative stress, cold stress, starvation and biotic attacks. Alternative oxidases have been identified in plants, fungi and algae. Caulerpa cylindracea, also known as terrorist seaweed, is an invasive marine green algae. Although the natural habitats of the species are Australia coasts, the impact of the invasion have been monitored through Mediterranean and Aegean shores. C. cylindracea species have advantages against others by showing higher resistance to stress conditions such as cold, starvation, pathogen attacks and by their capability of sexual and vegetative reproduction. In addition, C. cylindracea have degenerative effects on the growth of other species by reducing peripheral oxygen level, changing the chemical structure of the benthos and producing secondary metabolites. Comparing the advantages of C. cylindracea over the niche and defined functional roles of mitochondrial alternative oxidase proteins, it is evident that AOX proteins are likely involved developing those advantageous skills in C. cylindracea. However, previous research have focused on characterization of the species using phenotypic approaches. There is limited data about biochemical and molecular mechanisms that take part in stress resistance and invasion characteristics. Several characteristics that help C. cylindracea to have invasive power individually demonstrated to be under control of AOX proteins in other plant species at molecular level. Thus our general hypothesis is that invasive characteristics of C. cylindracea is directly related with AOX proteins. The working hypothesis is that the species express at least one AOX gene. To test this hypothesis, the aim of this study is to identify mitochondrial AOX protein encoding gene(s) in C. cylindracea. We collected samples from Seferihisar/İzmir and carried out transcriptome analysis. 27737 transcripts were described from assembled RNA-Seq data. Detailed bioinformatic analysis revealed two different genes encoding mitochondrial alternative oxidase proteins. When the Blast analysis performed via DNA sequence, there was no matching. Therefore, characterization studies on the bioinformatics level were continued based on protein sequences. The domain locations and sequence lengths of the matching sequences show high similarities (Matching percentages of 5 species is greater than 50%) with AOX proteins of the different species after the analysis. The sequence verifications of the identified AOX genes were made successfully and they were subcloned into yeast vector for future expression studies. The achieved transcriptome data and identified AOX sequences will guide to understand the invasive properties of the species.