Role of Sialylation in the Nervous System Development of Drosophila melanogaster

The sialyltransferase family is a group of enzymes that transfer sialic acid from donor CMP-Neu5Ac onto suitable carbohydrate chains of glycoproteins and glycolipids. In vertebrates, sialylation is implicated in many physiological and pathobiological processes, including nervous and immune system development and functioning, pathogen-host interaction, cancer cell proliferation and apoptosis. However, the complexity of the sialylation pathway and limitation of genetic and in vivo approaches interferes with functional analyses in mammalian organisms. We use Drosophila because of its simplified physiology and reduced genetic redundancy to characterize the evolutionarily conserved function of sialylation and to reveal its relationship to the role of sialic acids in humans. This dissertation focuses primarily on Drosophila sialyltransferase, DSIAT, so far the only sialyltransferase described in protostomes. Gene targeting of the DSIAT endogenous locus with a DSIAT-HA tagged version uncovered its remarkably dynamic stage- and cell-specific expression. I found that the expression of DSIAT is developmentally regulated and is restricted to motor neurons and cholinergic interneurons within the central nervous system of Drosophila. To reveal the role of DSIAT in development and functioning of fly nervous system I performed characterization of neurological phenotypes of DSIAT knockout flies, also generated by gene targeting approach. I observed that DSIAT mutant larvae are sluggish and have abnormal neuromuscular junction (NMJ) morphology. Electrophysiological analysis of mutant larval NMJ showed altered evoked NMJ activity. It was also observed that DSIAT knockout adult flies are paralyzed when are exposed to higher temperatures. Longevity assays showed that DSIAT adult mutants have significantly reduced life span. I used genetic interaction analysis to identify possible sialylated targets in Drosophila and found that ?-subunit of voltage gated sodium channel is a potential sialylated protein in the fly nervous system. All these data strongly supports the hypothesis that DSIAT plays an important role for neural transmission and development in Drosophila. This research work establishes Drosophila as a useful model system to study sialylation which may shed light on related biological functions in higher organisms including humans

Using the method of postisometric relaxation for the technique of posers improvement of the Latin American program

The aim of the research to create and experimentally substantiate complexes of exercises, based on the method of postisometric relaxation, directed toward technical poses improvement of the Latin American program by highly-qualified dancers. Research methods: For the pedagogical experiment two groups of dancers were formed (control and experimental group) each group included 12 people. Unlike the control group the training process of dancers from the experimental group included the complexes of physical exercises based on the methodology of postisometric relaxation. Pedagogical experiment was held during 6 months (since September, 2018 till February, 2019). In terms of the research we measured the development level of flexibility of different muscles groups and defined the degree of mastering the technique of poses fulfillment by dancers. Research results. We created the complexes of exercises, based on the methodology of postisometric relaxation, directed toward technique of poses fulfillment of the Latin American program by athletes- dancers. According to the results of statistic data handling it was revealed that the created by us complexes had positive influence on spine and hip joints flexibility development. It provided poses fulfillment technique development during competitive activity of athletes-dancers from the experimental group. Conclusion. Thus, using the method of postisometric relaxation during the training process of athletes- dancers provides purposeful increase of their technical mastery owing to qualitative poses fulfillment during competitive activity

The twisted Gene Encodes Drosophila Protein O-Mannosyltransferase 2 and Genetically Interacts With the rotated abdomen Gene Encoding Drosophila Protein O-Mannosyltransferase 1

The family of mammalian O-mannosyltransferases includes two enzymes, POMT1 and POMT2, which are thought to be essential for muscle and neural development. Similar to mammalian organisms, Drosophila has two O-mannosyltransferase genes, rotated abdomen (rt) and DmPOMT2, encoding proteins with high homology to their mammalian counterparts. The previously reported mutant phenotype of the rt gene includes a clockwise rotation of the abdomen and defects in embryonic muscle development. No mutants have been described so far for the DmPOMT2 locus. In this study, we determined that the mutation in the twisted (tw) locus, tw(1), corresponds to a DmPOMT2 mutant. The twisted alleles represent a complementation group of recessive mutations that, similar to the rt mutants, exhibit a clockwise abdomen rotation phenotype. Several tw alleles were isolated in the past; however, none of them was molecularly characterized. We used an expression rescue approach to confirm that tw locus represents DmPOMT2 gene. We found that the tw(1) allele represents an amino acid substitution within the conserved PMT domain of DmPOMT2 (TW) protein. Immunostaining experiments revealed that the protein products of both rt and tw genes colocalize within Drosophila cells where they reside in the ER subcellular compartment. In situ hybridization analysis showed that both genes have essentially overlapping patterns of expression throughout most of embryogenesis (stages 8–17), while only the rt transcript is present at early embryonic stages (5 and 6), suggesting its maternal origin. Finally, we analyzed the genetic interactions between rt and tw using several mutant alleles, RNAi, and ectopic expression approaches. Our data suggest that the two Drosophila O-mannosyltransferase genes, rt and tw, have nonredundant functions within the same developmental cascade and that their activities are required simultaneously for possibly the same biochemical process. Our results establish the possibility of using Drosophila as a model system for studying molecular and genetic mechanisms of protein O-mannosylation during development

Additional file 2: of Novel heterozygous pathogenic variants in CHUK in a patient with AEC-like phenotype, immune deficiencies and 1q21.1 microdeletion syndrome: a case report

Figure S2. The protein is composed of a protein kinase domain (orange), a leucine zipper region (green) and the NEMO binding-region (blue). Missense (gray) and loss of function (red) pathogenic variants found in the CHUK gene. Reported in this study (Bold). (TIFF 128 kb

Additional file 1: of Novel heterozygous pathogenic variants in CHUK in a patient with AEC-like phenotype, immune deficiencies and 1q21.1 microdeletion syndrome: a case report

Figure S1. DNA alignment of NGS data using Integrative Genomics Viewer (IGV). IGV snapshot of exon 13 of CHUK gene (NM_001278.3), located on chromosome 10, showing that the two variants (c.1365del, p.Arg457Aspfs*6; c.1388C > A, p.Thr463Lys) are present on different reads, indicating that they occurred on different chromosome (in trans). (TIFF 307 kb