Year: 2004
Type: dissertation
Abstract: Drosophila nemo (nrno) encodes a serinelthreonine kinase similar to the MAP kinases.It was first identified as an epithelial planar polarity gene involved in ommatidial rotation in the developing eye.It has since been shown to be a negative regulator of Wingless signaling and is essential for proper development.Nemo-like kinases (NLKs) have been identified in C. elegans, Xenopus, mice and humans, and have been shown biochemically to bind andlor phosphorylate Armadillo (Arm) homologues and members of the T-cell factorLymphocyte enhancing factor (TCFILEF) family of transcriptional regulators.xNLK has also been shown to bind the SOX1 1 transcriptional regulator.In Drosophila, loss of nrno results in reduced adult viability.Those that survive exhibit eye defects, mild wing patterning defects and are sterile.Loss of both maternal and paternal nrno contribution through the induction of mutant clones in the germ-line results in -80% embryonic lethality characterized by loss or fusion of denticle belts.I have characterized this embryonic phenotype and find that defects are consistent with a role for nrno in pair-rule gene patterning.This is based on the observations that denticle belt fusions occur in a pair-rule-like pattern, and stripes of Wingless (Wg) and Engrailed (En) protein expression are disrupted in alternating stripes.Additionally, I found expression of the nmo[P] reporter construct to be enriched in those regions of the embryo in which patterning defects usually manifest when nrno is lost.Embryos derived from nmogerm-lines were also examined for CNS and PNS defects, as the nrno reporter construct is also highly expressed in these tissues.Finally, I have examined a role for nrno in modulating expression of several Wingless target gene constructs in the embryo and wing disc.
Source: Summit (Simon Fraser University)
Author: Andrea C. Uetrecht
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W388964766