CSB429 Lecture 3 2/1/2013 3:53:00 PM
Germ plasm in Drosophila
- contains polar granules = large complex cels of protein and RNAs
Molecules to start making granules/ the starting protein is OSKAR (in flies – not conserved out
Oskar Vasa Tudor
What are these granules? This is present at the posterior
Where are the RNAs coming from? end
Maternal Factors: all factors put into the egg during oogenesis.
Many are proteins, the rest = RNAs
ZYGOTE - Maternal mRNAs specifically localized
to germ plam
- 3’ UTR of these mRNAs imp for the
- Experiment: KO the pathway to see
30% of the RNA in germ cells comes from the germ plasm.
BLASTODERM: large portion of the maternal mRNA are degraded w/ the exception of the
PGCs they preserve the maternal components!
Somatic cells mRNAs get
Primordial germ cells (170
transcripts) Two important processes:
- Localization of RNAs
- Degradation of RNAs in somatic but not the PGCs
Early embryo: - no transcription b/c it has things from oogenesis ]
- the mitosis cycle only consists of M and S phase (G1 and G2 are el