Study Guide for Exam 2 Zoology 470 2015 Exam format Remember that you can expect a good chunk of the exam to be short answer questions i e 1 2 sentence response Other types of questions including identification multiple choice matching and true false will also be present but don t count on them being the largest portion of the exam In addition there has been an emphasis in class on experiments and what they tell us about mechanisms of early development These are really important and you should understand them thoroughly The text should be used to reinforce in class material Your best study hints will come from last year s exam Remember that it s on the course web site Important reminder You are responsible for knowing the cleavage patterns presented in Gilbert Ch 5 and representative examples of each You already studied this for a quiz Topics for Exam 2 Note We are slightly behind the syllabus at this point the material on Exam 2 will only go through sea urchins Egg activation What is egg activation How is Src thought to lead to calcium elevation in sea urchin eggs after fertilization What ionic events are important for full egg activation e g calcium pH increase and what pathways lead to changes in each How does intracellular pH change following fertilization What experiments indicate the pH rise is required for the onset of protein synthesis What experiments demonstrate that protein synthesis is essential immediately after fertilization for normal development and that mRNA production is eventually required What cytoskeletal system and molecular motor drive pronuclear migration and what role is the sperm aster thought to play in this process What is parthenogenetic activation What is zona drilling Intracytoplasmic sperm injection ICSI Cleavage and the Blastula 1 Cleavage What cytoskeletal systems and molecular motor protein is involved How does the cell cycle during early cleavages differ from that of cells in the adult somatic cells What are cyclins What are reductive cleavages What does this mean for the embryo What are the basic types of cleavage and what organisms are good examples of each type What is the difference between radial and spiral cleavage and what groups of organisms display these types of cleavage How does the amount and position of yolk affect how cleavage occurs What significant accomplishments take place during cleavage e g regionalization blastocoel formation etc How are astral microtubules thought to stimulate where the cleavage furrow forms Can you cite an experiment that shows this What is Rho and why is it important in stimulating cleavage furrows 2 Blastula structure How does the yolk content of the egg affect blastula structure The Anatomy of Genes What are the basic steps in the production and processing of mRNA How does chromatin structure affect the possibility of transcription How do histone methylation acetylation and DNA methylation affect the likelihood of transcription of a gene What are the functions of the various regions of DNA associated with the production of a functional mRNA e g enhancer or regulatory elements promoter region What are the functions of various parts of an mRNA e g introns exons 3 untranslated region poly A tail Zoo 470 2015 Study Guide for Exam 2 Page 2 Transcriptional regulation of specific genes1 DNA binding proteins and DNA regulatory domains In general how do transcription factors interact with DNA What effect does transfection of cultured cells with MyoD1 have What role are MyoD1 myogenin and myf 5 thought to play in myogenesis i e what are myogenic factors What kind of proteins are steroid hormone receptors What role does pax 6 small eye eyeless aniridia play in specifying eye structures in diverse organisms What experiments suggest this 2 Promoters What is a promoter An enhancer How can we use reporter constructs to study how these pieces of DNA regulate transcriptional activation Why are reporter constructs advantageous General Regulation of Gene Expression RNA Processing and Translational Control What is the difference between maternal and zygotic mRNAs When are they made What is the mid blastula transition in Xenopus What effect does the nucleus cytoplasm ratio have on the onset of the mid blastula transition How can this ratio be altered experimentally How can alternative splicing be used to regulate RNA function What are some ways in which the translation of mRNAs might be regulated How are 3 UTRs thought to function in regulation of translation How does the 3 UTR regulate spatial localization of mRNAs Sex Determination What differences in Wolffian and M llerian duct regression are there in the male and female reproductive systems What do they become How do the parts of the primitive sex cords differentiate in males and females What does M llerian inhibitory substance hormone do How is the sry gene thought to regulate primary sexual differentiation in mammals and what evidence is there for its role Based on gene translocations why is Sry thought to act as a male gene What autosomal gene is thought to act downstream of Sry hint what is Sox9 What happens when androgen receptors are defective in humans who are genetically male androgen insensitivity syndrome What is meant by an indifferent gonad What cells produce testosterone in the testis What is the evidence that Wnt4 leads to full female gonadal differentiation Is testosterone produced in both males and females Hint from what precursor is estrogen synthesized in females Germ Cells 1 Review Localized determinants How can localized determinants be used to generate differences in early embryos Problem Set 2 should have helped prepare you for how to work with germ cells 2 Germ plasm in C elegans What are P granules What role do the par genes play in regulating early asymmetries in C elegans What is germ plasm What are some components of P granules and other germ plasm e g RNA helicases mitochondrial nuage etc What role does PIE 1 protein play in transcriptional inactivation in early C elegans embryos 3 Germ plasm in Drosophila What is pole plasm in Drosophila What are pole cells What experiments show that pole plasm confers special properties on the cells that receive it What role does oskar play in localizing pole plasm constituents at the posterior pole of the oocyte What experiments show that oskar localization determines where pole cells form 4 Primordial germ cell migration in vertebrates What molecular signal do primordial germ cells PGCs use to migrate