Drosophila Flashcards
Stage in Drosophila where the nuclei have migrated to the edges, and membranes are forming, but are not complete
Syncytial Blastoderm
Stage in Drosophila with complete cells outlining the inner yolk
Cellular Blastoderm
What three components work to cellularize the blastoderm?
Microtubules stretch downwards from the nucleus, actin concentrates at the lowest in pockets, furrowing the membrane, and Cadherin junctions form down the crevice to maintain cellular adhesion.
What external quality of drosophila allow researchers to see which segments might be missing?
Denticle bands
What experiment proves that there are maternal polarity centers in the cytoplasm?
Draining anterior cytoplasm and adding posterior cytoplasm creates two posteriors.
What do each mutant mRNAs [bicoid, nanos, torso] cause to be missing?
Bicoid - missing anterior. Nanos - missing posterior
Torso - missing terminal
Where do bicoid and nano localize to, and with what carrier protein, and what motor?
Bicoid is carried by Exuperantia and dynein to the anterior. Nanos is carried by Oskar to the posterior.
Effects of bicoid mRNA tightly localized to the anterior
Creates a gradient of bicoid protein towards the anterior. Prevents translation of caudal mRNA,and translates hunchback.
Effects of nanos mRNA in tightly localized to the posterior
Creates a gradient of nanos protein towards the posterior. Prevents translation of hunchback, by binding of pumilio protein.
Gap Genes list
Gt, Hb, Kr, Kni, Gt, Hb
Hunchback: Maternal or zygotic?
Both
Gap genes: maternal or zygotic?
zygotic
Pair Rule Genes:
7 stripe pattern in the syncytial blastoderm
Segment Polarity Genes
14 stripe pattern in the cellular blastoderm
What is an example of a pair rule gene?
Fushi tarazu
What is even skipped?
A gene that correlates with the overlap of gap proteins.
How does even skipped determine which pair rule gene to express?
Even skipped has specific enhancer elements whose regulators are bicoid and other gap proteins.
Example of segment polarity gene
Engrailed
What separates the segment polarity genes?
An adjacent hedgehog wingless relationship.
Positive feedback of wingless and hedgehog
Wingless protein is a Wnt that activates a frizzled, and through Disheveled, and Armadillo, activates transcription of engrailed and hedgehog. Hedgehog travels to a patched and smoothened receptor and through cubitus interruptus, it creates transcription of wingless.
What is the start of gastrulation called for Drosophila?
The Ventral Furrow that involves apical constriction.
What morphogenic movement creates the germ band in Drosophila?
Convergent Extension
What are the proteins and alignments relative to the axis of extension?
The actin/myosin are orthogonal to the axis, and PAR3/Bazooka is parallel
What shapes do cells create prior to extension?
Myosin contraction forms rosettes of cells
Explain attennapedia
Where a drosophila has legs instead of antennae
UltraBithorax Complex
two sets of wings
In what order are homeotic genes anterior-posterior?
3’-5’
Roughly equivalent Hox genes in mammals are called
paralogs
Homeodomain
Similar domain in proteins between all metazoa
Homeobox
Corresponding DNA to create the homeodomain throughout metazoan
