notes exam II

notes exam II - animal development: notes for exam i...

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Unformatted text preview: animal development: notes for exam i Fertilization a. Sea urchin > bindin 1. Bindin to egg vitelline envelope b. Fertilization cone (sea urchins only) actin c. Sperm 1. Produced in seminiferous tubule 2. Into epididymus = maturation 3. Capacitation > w/in female 4. Must travel through zona pellucid d. Mouse fertilization 1. Sperm activated by female rep. tract 2. Sperm binds to zona 3. Acrosomal rxn 4. Sperm lyes hole in zona 5. Sperm + egg membranes fuse e. Mammals 1. Bind to zona 2. Acrosome rxn 3. Ca2+ in sperm head causes fusion w/ cumulus layer Releases digestive enzymes f. Zona fibrous 3 proteins 1. Zp1 cross link zp2/3 fibers 2. Zp2/3 form long fibers 3. Experiment: zp3 competition Culture medium w/ sperm + oocytes (in vitro fert.) Culture/ ivf o w/ zp1, 2, or 3, add it in w/ sperm if sperm bind to it, will not be able to bind to oocyte = competition experiment Results o Zp3 is responsible for sperm binding in zona g. sperm fusion 1. cortical granules rearrange zona unit 5: egg activation a. cell signaling ca2+ + ip3 1. pip2 cleaved to dag + ip3 stimulates ca2+ release in endoplasmic reticulum b. permanent block to polyspermy ca2+ dependent 1. calcium wave sweeps across egg causes cell physiological/metabolic changes calcium ionophores- drugs that elicit ca2+ release, can induce waves t riggers cortical granule release calcium atpase used to pump ions 2. phospholipase c cleaves pip2 dag + ip3 o ip3 to er o ca ion release c. long term conseq of ca2+ release 1. stimulates: cell div dna synthesis rna t ranslat ion 2. na+ /H= : results in ph increase in cytoplasm important in max stimulat ion 3. pumps 4. antiporters ion exchangers 5. maternal mrnas used early, zygotic mrnas later d. drugs 1. actinomycin d = blocks new transcription ultimately embryos arrest 2. cyclohexamide = blocks translation arrest as aborted 1 cell zygote e. protein synthesis = best w/ increase in ph, ca2+ release f. pronuclear migration sperm/egg pronuclei fusion g. female = no centrosome (centrioles) 1. sperm brings in the centrosome to the zygote 2. sperm aster = microtubule starburst pattern dynein responsible for movement dynactin linker proteins 3. mammals = syngamy = align, do not mix 4. azospermia lack of sperm production obstructive blockage in testes +others int racytoplasm ic sperm injection (icsi) parthenogenetically activated eggs (parthenotes) o use calcium ionophore/drug that suppresses first cleavage (dmat) o restores diploid genome unit 6: cleavage = embryonic cell division **know patterns of cleavage in representative examples p....
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notes exam II - animal development: notes for exam i...

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