Dendrite growth and spermatogenesis in Drosophila are regulated by clathrin-mediated trafficking
Abstract
Many animal development processes, such as neuronal growth and spermatogenesis, are actively regulated by intracellular membrane trafficking pathways. One well-known membrane trafficking pathway is the clathrin-mediated trafficking pathway. Important clathrin regulators include Actin-related kinase (Ark) family proteins, which have been implicated in biochemical modifications of clathrin adaptors. However, the physiological role of Ark family members during animal development was only partially understood. Here I use Drosophila melanogaster as a model system to study the function of the Ark family proteins Numb-associated kinase and Auxilin. Microscopic and ultrastructural morphology of auxilin mutants, the rescue of the auxilin phenotype via ectopic expression of wild type and domain-deleted variants of Auxilin, and the way clathrin and adaptor protein localizations are affected by auxilin mutation together show that Auxilin is essential for clathrin-coated vesicle formation at TGN to support germ cell plasma membrane growth during Drosophila spermatogenesis. In contrast, phenotypic studies indicate that nak mutation affects dendrite arborization. Genetic interaction between nak and clathrin-mediated endocytosis, and the effects of nak mutation on dendritic clathrin puncta localization and local dendrite growth show that Nak functions in neuronal growth by regulating the localization of clathrin-mediated endocytosis machinery in developing high-order dendrites. Taken together, both neuronal growth and spermatogenesis in Drosophila are regulated by specific clathrin-mediated trafficking pathways.
Degree
Ph.D.
Advisors
Aguilar, Purdue University.
Subject Area
Developmental biology
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