BIOL303 Lecture Notes - Ribonucleoprotein, Microfilament, Colchicine
28 Oct 2013
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Document Summary
Rapid specification of blastomeres by products of zygotic genes and by maternally provided transcripts and proteins. C. elegans are hermaphrodites: having both male and female reproductive parts. Elongated egg shape defines future anterior-posterior axis > decision for anterior end relates to position of sperm pronucleus. P-granules: ribonucleoprotein complexes containing translation regulators that specify the germ cells in c. elegans and are localized by par ( partitioning ) proteins. They are initially spread out evenly throughout the cell but after fertilization they become localized in the posterior. P1 then divides more p granules and they are inherited by p2 cells. They are then associated with nucleus that then becomes p3, p4 forms germ line. Experiment: drug treatment cytochalasin d (disrupts microfilaments) prevents. Colchicine (disrupts microtubules) does not prevent p-granule localization: c. elegans development uses both autonomous and conditional specification. Explain with reference to the two-cell and four-cell stage.
