%0 PDF %T Characterization of Chitin Synthases and Chitin Deacetylases that Function During the Development of the Nematode Caenorhabditis elegans. %A Heustis, Ronald. %8 2017-04-24 %R http://localhost/files/5q47s121x %X Abstract: Chitin (beta-1,4-linked-N-acetylglucosamine) is a major structural macromolecule in nematodes. Its presence in the eggshell and the lining of the pharynx confers protective benefits and also facilitates important steps of development. Chitin metabolism is considered to be highly conserved within roundworms - but not in the many plants and vertebrates that are parasitized by some of them - so research on chitin metabolism will provide knowledge on basic aspects of invertebrate development and may also provide a foundation from which to develop new drugs or vaccines targeting parasitic nematodes. This dissertation encompasses various projects aiming to deepen our understanding of the chitin synthases and chitin deacetylases that function during nematode development. This body of work is the first showing that polysaccharide deacetylases (which can convert chitin to chitosan) are encoded in a diverse array of nematode genomes. Two copies of these genes are found in C. elegans where they are somatically expressed and affect development since their loss results in a retardation of growth. Our knowledge of transcript numbers and sequences, as well as on the dynamics of their expression, is incomplete. Proteins with bona fide chitin deacetylase activity are produced in C. elegans, and while low levels of carbohydrate limit our ability to demonstrate the presence of chitosan using standard biochemical techniques, we show that chitosan is localized to the C. elegans pharynx because it stains with the dye Eosin Y. Chitin synthases convert UDP-N-acetylglucosamine into the high molecular weight homopolymer chitin and previously published work has shown that the two genes act non-redundantly to deposit chitin in the nematode eggshell and pharynx. The work in this dissertation further characterizes the germline expression of the chs-1 gene and investigates novel roles and expression patterns for both chs-1 and chs-2. The enzymatic properties of the germline and somatic chitin synthase proteins are also studied and presented along with attempts to confirm the presence of novel chitinous structures. This dissertation closes with a perspective on future directions of study for nematode chitin synthases and chitin deacetylases and outlines the significance of these enzymes in the context of biochemistry, developmental biology and parasitology.; Thesis (Ph.D.)--Tufts University, 2012.; Submitted to the Dept. of Biology.; Advisor: Juliet Fuhrman.; Committee: Susan Ernst, Mitch McVey, Harry Bernheim, and John Samuelson.; Keywords: Biology, Developmental biology, and Biochemistry. %[ 2022-10-11 %9 Text %~ Tufts Digital Library %W Institution