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Yi, K.

Publications and source records attributed to Yi, K..

2 recordsLinked to original sources

Wampa is a dynein subunit required for axonemal assembly and male fertility in Drosophila

Axonemal dyneins are motor proteins that form the inner and outer arms of the axoneme in cilia and flagella. Defects in dynein arms are the leading cause of primary ciliary dyskinesia (PCD), which is characterized by chronic respiratory infections, situs inversus, and sterility. Despite current understanding of pathological features associated with PCD, many of their causative genes still remain elusive. Here we analyze genetic requirements for wampa (wam), a previously uncharacterized component of the outer dynein arm that is essential for male fertility. In addition to a role in outer dynein arm formation, we uncovered additional requirements during spermatogenesis, including regulation of remodeling events for the mitochondria and the nucleus. Due to the conserved nature of axonemal dyneins and their essential role in both PCD and fertility, this study advances our understanding of the pathology of PCD, as well as the functional role of dyneins in axonemal formation and spermatogenesis.

developmental biology

Subcellular analyses of planarian meiosis implicates a novel, double-membraned vesiculation process in nuclear envelope breakdown

AO_SCPLOWBSTRACTC_SCPLOWThe cell nuclei of Ophisthokonts, the eukaryotic supergroup defined by fungi and metazoans, is remarkable in the constancy of both their double-membraned structure and protein composition. Such remarkable structural conservation underscores common and ancient evolutionary origins. Yet, the dynamics of disassembly and reassembly displayed by Ophisthokont nuclei vary extensively. Besides closed mitosis in fungi and open mitosis in some animals, little is known about the evolution of nuclear envelope break down (NEBD) during cell division. Here, we uncovered a novel form of NEBD in primary oocytes of the flatworm Schmidtea mediterranea. From zygotene to metaphase II, both nuclear envelope (NE) and peripheral endoplasmic reticulum (ER) expand notably in size, likely involving de novo membrane synthesis. 3-D electron microscopy reconstructions demonstrated that the NE transforms itself into numerous double-membraned vesicles similar in membrane architecture to NE doublets in mammalian oocytes after germinal vesicle breakdown. The vesicles are devoid of nuclear pore complexes and DNA, yet are loaded with nuclear proteins, including a planarian homologue of PIWI, a protein essential for the maintenance of stem cells in this and other organisms. Our data contribute a new model to the canonical view of NE dynamics and support that NEBD is an evolutionarily adaptable trait in multicellular organisms.

cell biology