Abstract:Septins are evolutionary conserved GTP-binding proteins and form heterooligomers in cells to interact with cytoskeleton. The main roles of septins in cell are cytokines, membrane interactions, vesicle trafficking and microtubule and actin organization. Non-coding RNAs are key players of gene expression regulation. Small-interfering RNAs (siRNAs) belong to non-coding RNAs, are characterized by sequence complementarity to their target mRNAs. siRNAs silence their targets via mRNA degradation or inhibition of translation. In S. pombe siRNAs can also propagate heterochromatin to silence genes located in centromeric regions. In this study, the aim was understanding the results of extrinsically induced siRNA silencing in S. pombe by using synthetic siRNAs specific to Septin 1 gene. siRNAs were introduced to cells by lipid-based vesicles and the alterations in Septin 1 expressions were monitored with qPCR. Septin 1 expression was reduced dramatically via direct siRNA introduction to cells. The interactions between cell morphology and the reduced level of Septin 1 were observed after accomplishing the silencing of Septin 1 gene. In this study, it is shown that the morphology of the cells is affected by the reduced levels of Septin 1 expression and the cells form long and chain-like structures. This study constitutes an important example in understanding the results of inducing siRNA silencing extrinsically in S. pombe.

This study focuses on the effect of iron on hexose transporters which perform glucose uptake. For this aim, we investigated the role of iron in glucose utilization and expression of hexose transporters in Schizosaccharomyces pombe. We applied different iron concentrations (1, 2, 5, 10 mM) to the cells grown up to mid-logarithmic phase. According to analysis of cell viability and morphology, we determined 2 mM and 5 mM as non-toxic and toxic doses, respectively. Besides, glucose consumption efficiency increased (1.5-fold) in the cells which were exposed to these iron concentrations. qRT-PCR analysis of hexose transporter genes showed that the expression of ght2 and ght8 genes were downregulated under both non-toxic and toxic iron conditions, but that of ght5 gene was significantly decreased only by toxic iron dose. In conclusion, it was suggested for the first time in this study that the Ght5 protein, as being high affinity hexose transporter, might play a role in sensing and signaling of iron stress. K E Y W O R D Shexose transporters, iron stress, Schizosaccharomyces pombe

BackgroundGlucose both is the favorite carbon and energy source and acts as a hormone that plays a regulated role in many biological processes. Calorie restriction extended lifespan in many organisms, including Schizosaccharomyces pombe, while uptake of high glucose led to undesired results, such as diabetes and aging.Methods and ResultsIn this study, sequence analysis of Schizosaccharomyces pombe ird5 and ird11 mutants was performed using next-generation sequencing techniques and a total of 20 different mutations were detected. ird11 is resistant to oxidative stress without calorie restriction, whereas ird5 displays an adaptive response against oxidative stress. Candidate 9 mutations, which are thought to be responsible for ird5 and ird11 mutant phenotypes, were investigated via forward and reverse mutations by using various cloning techniques.ConclusionThe results of this study contribute to the basic sciences by showing the relationship between glucose sensing/signaling and oxidative stress response components.

Gua1 gene in Schizosaccharomyces pombe encodes inosine 5′-monophosphate dehydrogenase (IMPDH), which catalyzes the first step in de novo biosynthesis of guanosine monophosphate (GMP). Knockout cassette was constructed with polymerase chain reaction (PCR)-based gene targeting technique for deletion of gua1 gene in S. pombe and this knockout cassette was transformed to S.s pombe wild type (972h-). Knockout cassette contains 653 and 285 bp sequences which are upstream and downstream of gua1 gene, respectively, in S. pombe genome and kanamycin resistance gene obtained from pFA6 plasmid. After transformation using lithium acetate method, knockout cassette is aimed at replacing with the sequences of gua1 gene via homologous recombination. The transformant 972h colonies which integrated knockout cassette to the genome via homologous recombination are selected in YEA medium with antibiotic G418 after transformation and in this step, possible mutant colonies in gua1 gene were determined. Finally, colony PCR techniques were performed to control whether the deletion is made in the right place or not. The results show that the gua1 gene deleted strain was obtained.

The aim of the study was to investigate the efficiency of ram seminal plasma and fetal calf serum on freezing of buck semen. Twenty ejaculates were collected using an electro‐ejaculator and split into six groups. While FCS additive was not used in A1, A2 and A3 groups, 10% FCS was added to B1, B2 and B3 groups. These groups were then edited according to whether the buck or ram SP was involved. The design of the groups was done as follows: Group A1 (control 1), group A2 without buck SP, group A3 containing ram SP instead of buck SP. Groups B1 (control 2), B2 and B3 were the FCS added forms of these groups. Progressive sperm motility percentages in Group A1 and Group B2 were found to be higher when compared to the lowest Group B3. There were no significant differences between the groups in neither the levels of reactive oxygen species nor the enzyme and glutathione activities. In conclusion, the lack of statistical difference between the groups suggested that despite the supplements used but only when the buck spermatozoa structure was healthy, the cell could preserve acrosome, DNA and the integrity of membrane.

No abstract