| Non-Scientific Abstract The hindbrain is part of the central
nervous system (which includes the brain and the spinal chord). Some of the hindbrain¹s
functions include helping organisms with coordinating movement and maintaining balance.The
development of the hindbrain can be traced back to the embryo (from which all parts of our body
are derived). The hindbrain forms through the activation of certain genes in the embryo.When
these genes are activated and start working,RNA is produced using the DNA as a blueprint.RNA in
turn serves as a blueprint for the synthesis of protein, which makes up part of the
hindbrain.The molecule studied in this project was nlz1, a protein that is thought to
help activate the genes involved in the development of the hindbrain. The purpose of this study
was to identify other proteins that, together with nlz1, activate these genes.We
identified four proteins that may be involved in hindbrain formation along with nlz1.
Previously, the Sive Lab identified genes that are active in the same regions of the embryo as
nlz1.We also tested whether or not these genes help nlz1 in hindbrain
development.Currently,we are working on identifying more proteins that may help nlz1 with
activating genes involved in hindbrain formation.
Abstract
The transcription factor nlz1 (nocA-like Zn finger) is expressed posteriorly in the future
hindbrain during gastrulation.Overexpression of nlz1 causes disruption of hindbrain formation.
Since nlz1 is expressed only in certain parts of the embryo and the effects of overexpression
are limited to specific regions of the hindbrain,we postulated that the activity of nlz1 is
modulated by other proteins. In order to isolate proteins which interact with nlz1, we used a
yeast two-hybrid screen. This consisted of a reporter strain containing constructs of nlz1 of
various length fused with LexA DNA binding domain protein (the bait) and a cDNA library (cDNA
constructed from zebrafish mRNA harvested at late gastrulation fused with a B42 activation
domain). Previously, the two-hybrid screen was used to isolate four clones from a cDNA library
which encode candidate proteins that may interact with nlz1. The functions of these four
proteins are currently being studied. The same two-hybrid screen method was used in this study
with 50 putative positive clones identified, none of which resulted in a positive clone.
Interaction between nlz1 and known genes (meis, lmo4, pbx4, hoxb1b) that are expressed in the
same regions of the embryo was also tested using the two-hybrid method. None of the known genes
tested (hoxb1b and lmo4) to date interact with nlz1. This study forms the beginning of an effort
to isolate nlz1-interacting proteins. |
