Darrell J Killian

• Ph.D. New York University
• Professor (Associate) at Colorado College

The regulation of dendritic branching is critical for sensory reception, cell-cell communication within the nervous system, learning, memory, and behavior. Defects in dendrite morphology are associated with several neurological disorders, thus an understanding of the molecular mechanisms that govern dendrite morphogenesis is important. Recent inves...

The large number of RNA binding proteins and translation factors encoded in the Drosophila and other metazoan genomes predicts widespread use of post-transcriptional regulation in cellular and developmental processes. Previous studies identified roles for several RNA binding proteins in dendrite branching morphogenesis of Drosophila larval sensory...

Objective RNA-binding proteins (RBPs) are important regulators of gene expression that influence mRNA splicing, stability, localization, transport, and translational control. In particular, RBPs play an important role in neurons, which have a complex morphology. Previously, we showed that there are many RBPs that play a conserved role in dendrite d...

RNA-binding proteins play an important role in the regulation of post-transcriptional gene expression throughout the nervous system. This is underscored by the prevalence of mutations in genes encoding RNA splicing factors and other RNA-binding proteins in a number of neurodegenerative and neurodevelopmental disorders. The highly conserved alternat...

Cytoplasmic polyadenylation element binding proteins (CPEBs) are widely conserved proteins that regulate the length of poly(A) tails in the cytoplasm, regulate translation, and regulate mRNA transport. While CPEBs are best known for regulating maternal messages in oocytes, CPEBs also have roles in many other cell types including neurons. Here we ex...

RNA binding proteins (RBPs) mediate posttranscriptional gene regulatory events throughout development. During neurogenesis, many RBPs are required for proper dendrite morphogenesis within Drosophila sensory neurons. Despite their fundamental role in neuronal morphogenesis, little is known about the molecular mechanisms in which most RBPs participat...

The Caenorhabditis elegans gene sup-26 encodes a well-conserved RNA-recognition motif-containing RNA-binding protein (RBP) that functions in dendrite morphogen-esis of the PVD sensory neuron. The Drosophila ortholog of sup-26, alan shepard (shep), is expressed throughout the nervous system and has been shown to regulate neuronal remod-eling during...

Sex-determination in Caenorhabditis elegans requires regulation of gene transcription and protein activity and stability. sel-10 encodes a WD40-repeat-containing F-box protein that likely mediates the ubiquitin-mediated degradation of important sex-determination factors. Loss of sel-10 results in a mild masculinization of hermaphrodites, whereas do...

Years of research have identified a highly conserved mechanism required for apoptotic cell killing. How certain cells are specified to die is not well understood. With a rich history in programmed cell death research, the nematode C. elegans offers an excellent animal model with which to study cell death specification events. Developing hermaphrodi...

Ribosome biogenesis is a cell-essential process that influences cell growth, proliferation, and differentiation. How ribosome biogenesis impacts development, however, is poorly understood. Here, we establish a link between ribosome biogenesis and gonadogenesis in Caenorhabditis elegans that affects germline proliferation and patterning. Previously,...

We report molecular genetic studies of three genes involved in early germ-line proliferation in Caenorhabditis elegans that lend unexpected insight into a germ-line/soma functional separation of autosomal/X-linked duplicated gene pairs. In a genetic screen for germ-line proliferation-defective mutants, we identified mutations in rpl-11.1 (L11 prote...

Interactions between the somatic gonad and the germ line influence the amplification, maintenance, and differentiation of germ cells. In Caenorhabditis elegans, the distal tip cell/germline interaction promotes a mitotic fate and/or inhibits meiosis through GLP-1/Notch signaling. However, GLP-1-mediated signaling alone is not sufficient for a wild-...

Strict spatial and temporal regulation of proliferation and differentiation is essential for proper germline development and often involves soma/germline interactions. In C. elegans, a particularly striking outcome of defective regulation of the proliferation/differentiation pattern is the Pro phenotype in which an ectopic mass of proliferating ger...

We investigated the control of proliferation and differentiation in the larval Caenorhabditis elegans hermaphrodite germ line through analysis of glp-1 and lag-2 mutants, cell ablations, and ultrastructural data. After the first several rounds of germ cell division, GLP-1, a receptor of the LIN-12/Notch family, governs germline proliferation. We an...

glp-1 encodes a member of the highly conserved LIN-12/Notch family of receptors that mediates the mitosis/meiosis decision in the C. elegans germline. We have characterized three mutations that represent a new genetic and phenotypic class of glp-1 mutants, glp-1(Pro). The glp-1(Pro) mutants display gain-of-function germline pattern defects, most no...

In Drosophila, the gradient of the Bicoid (Bcd) morphogen organizes the anteroposterior axis while the ends of the embryo are patterned by the maternal terminal system. At the posterior pole, expression of terminal gap genes is mediated by the local activation of the Torso receptor tyrosine kinase (Tor). At the anterior, terminal gap genes are also...

The Drosophila ommatidia contain two classes of photoreceptor cells (PR's), the outer and the inner PR's. We performed an enhancer trap screen in order to target genes specifically expressed in PR's. Using the UAS/GAL4 method with enhanced green fluorescent protein (eGFP) as a vital marker, we screened 180000 flies. Out of 2730 lines exhibiting new...

Typescript. Thesis (Ph. D.)--New York University, Graduate School of Arts and Science, 2004. Includes bibliographical references (leaves 220-247).