E55-2009 practice exam 3 key

27 blastema analogous to the progress zone both are

Info icon This preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
27. blastema analogous to the progress zone; both are highly proliferative groups of cells that provide the substrate for limb extension. 28. A. Identifiy hemangioblast-specific gene, and utilize the promoter of this gene to drive GFP or lacZ. This experiment could be done easily in zebrafish or mammals. B. Expect labeled cells on the yolk sac, and possibly on (but not necessarily) the AGM, fetal liver, and bone marrow. C. Expect labeled cells just on the yolk sac. 29. The ethical complication has to do with the origin of ES cells opposed to iPS cells. ES cells are procured by removing ICM cells from an early embryo, thereby destroying a human embryo. iPS start with cultured somatic adult cells, and experiments that transform these cells into pluripotent cells. 30. A. These are large macromolecular complexes comprised of RNA and proteins. B. turn on germ-cell specific genes, silence transposable elements, maintain pluripotency of the germ cell. C. testes cords, as the germ cells are present there. D. You might expect SDF-1 to be expressed in a path/route along endoderm, final destination being the gonadal ridge, as germ cells are induced outside the embryo proper and undergo directed migration to reach the site of the developing gonad. E. Overexpress SDF-1 mRNA (or misexpress with transgenic system) in zebrafish. If SDF-1 is sufficient to direct PGC migration, this message alone should alter the routes of PGC cells, and in this case we expect ‘confused’ migration due to the presence of ectopic ligand in places where it should not be found.
Image of page 1
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern