▪ Abstract Virtually every cell type in metazoan organisms produces heparan sulfate. These complex polysaccharides provide docking sites for numerous protein ligands and receptors involved in diverse biological processes, including growth control, signal transduction, cell adhesion, hemostasis, and lipid metabolism. The binding sites consist of relatively small tracts of variably sulfated glucosamine and uronic acid residues in specific arrangements. Their formation occurs in a tissue-specific fashion, generated by the action of a large family of enzymes involved in nucleotide sugar metabolism, polymer formation (glycosyltransferases), and chain processing (sulfotransferases and an epimerase). New insights into the specificity and organization of the biosynthetic apparatus have emerged from genetic studies of cultured cells, nematodes, fruit flies, zebrafish, rodents, and humans. This review covers recent developments in the field and provides a resource for investigators interested in the incredible dive...

Order out of chaos: assembly of ligand binding sites in heparan sulfate.

The last decade has seen an enormous expansion in the genetic toolbox of model organisms. This has been particularly apparent in the fruitfly, Drosophila melanogaster, in which the development of these tools and their ongoing extension, along with the completion of the genome sequence has allowed for the analysis of most any process. One particularly elegant example of tool development was the creation of the GAL4/UAS system for targeted gene expression in Drosophila. In addition to helping make Drosophila one of the most genetically tractable metazoans, this system has also helped Drosophila attract attention from the biotechnology industry as a viable means to investigate the function of genes implicated in a wide variety of medically and economically important processes. In this article, we review the GAL4/UAS system in Drosophila and the numerous extensions that have morphed it into a veritable Swiss army knife for the analysis of gene function.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/gene.10150

GAL4 system in Drosophila: a fly geneticist's Swiss army knife.

https://www.cell.com/current-biology/pdf/S0960-9822(05)00789-X.pdf

Molecular, anatomical, and functional organization of the Drosophila olfactory system

http://web.stanford.edu/group/luolab/Pdfs/Luo_Callaway_Svoboda_Neuron_2008.pdf

Genetic dissection of neural circuits.

Researchers have long predicted that complex carbohydrates on cell surfaces would play important roles in developmental processes because of the observation that specific carbohydrate structures appear in specific spatial and temporal patterns throughout development. The astounding number and complexity of carbohydrate structures on cell surfaces added support to the concept that glycoconjugates would function in cellular communication during development. Although the structural complexity inherent in glycoconjugates has slowed advances in our understanding of their functions, the complete sequencing of the genomes of organisms classically used in developmental studies (e.g., mice, Drosophila melanogaster, and Caenorhabditis elegans) has led to demonstration of essential functions for a number of glycoconjugates in developmental processes. Here we present a review of recent studies analyzing function of a variety of glycoconjugates (O-fucose, O-mannose, N-glycans, mucin-type O-glycans, proteoglycans, glycosphingolipids), focusing on lessons learned from human disease and genetic studies in mice, D. melanogaster, and C. elegans.

Role of Glycosylation in Development

Shigeo Hayashi,* Kei Ito, Yukiko Sado, Misako Taniguchi, Ai Akimoto, Hiroko Takeuchi, Toshiro Aigaki, Fumio Matsuzaki, Hideki Nakagoshi, Teiichi Tanimura, Ryu Ueda, Tadashi Uemura, Motojiro Yoshihara, and Satoshi Goto National Institute of Genetics, Mishima, Shizuoka-ken, Japan Department of Genetics, Graduate University for Advanced Studies, Mishima, Shizuoka-ken, Japan Riken Center for Developmental Biology, Kobe, Hyogo, Japan National Institute for Basic Biology Myodaiji, Okazaki, Aichi, Japan Department of Biology, Tokyo Metropolitan University, Tokyo, Japan Department of Developmental Neurobiology, Institute of Development, Aging and Cancer, Tohoku University, Aoba-ku, Sendai, Japan Okayama University Graduate School of Natural Science and Technology, Okayama, Japan Department of Biology, Graduate School of Sciences, Kyushu University, Ropponmatsu, Fukuoka, Japan Mitsubishi Kagaku Institute of Life Sciences, Tokyo, Japan Laboratory of Molecular Genetics, Institute for Virus Research, Kyoto University, Kyoto, Japan Center for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA

https://onlinelibrary.wiley.com/doi/pdf/10.1002/gene.10137

GETDB, a database compiling expression patterns and molecular locations of a collection of gal4 enhancer traps

Glycosylation modifies protein activities in various biological processes. Here, we report the functions of a novel UDP-sugar transporter (UST74C, an alternative name for Fringe connection (Frc)) localized to the Golgi apparatus in cellular signalling of Drosophila. Mutants in the frc gene exhibit phenotypes resembling wingless and Notch mutants. Both Fringe-dependent and Fringe-independent Notch pathways are affected, and both glycosylation and proteolytic maturation of Notch are defective in mutant larvae. The results suggest that changes in nucleotide-sugar levels can differently affect Wingless and two distinct aspects of Notch signalling.

UDP–sugar transporter implicated in glycosylation and processing of Notch

RNA interference (RNAi) has emerged as a powerful tool to silence specific genes. Vector-based RNAi systems have been developed to downregulate targeted genes in a spatially and temporally regulated fashion both in vitro and in vivo. The zebrafish (Danio rerio) is a model animal that has been examined based on a wide variety of biological techniques, including embryonic manipulations, forward and reverse genetics, and molecular biology. However, a heritable and tissue-specific knockdown of gene expression has not yet been developed in zebrafish. We examined two types of vector, which produce small interfering RNA (siRNA), the direct effector in RNAi system; microRNA (miRNA) process mimicking vectors with a promoter for RNA polymerase II and short hairpin RNA (shRNA) expressing vector through a promoter for RNA polymerase III. Though gene-silencing phenotypes were not observed in the miRNA process mimicking vectors, the transgenic embryos of the second vector (Tg(zU6-shGFP)), shRNA expressing vector for enhanced green fluorescence protein, revealed knockdown of the targeted gene. Interestingly, only the embryos from Tg(zU6-shGFP) female but not from the male fish showed the downregulation. Comparison of the quantity of siRNA produced by each vector indicates that the vectors tested here induced siRNA, but at low levels barely sufficient to silence the targeted gene.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/dgd.12091

Yukiko Sado

Papers

GETDB, a database compiling expression patterns and molecular locations of a collection of gal4 enhancer traps

UDP–sugar transporter implicated in glycosylation and processing of Notch

Properties of gene knockdown system by vector-based siRNA in zebrafish.