exam 2- fate mapping

Question 1

___ are general territorial plans of embryonic development

Answer 1

fate maps

Question 2

fate maps describe the sequence of ___, ___, and ___ that follow from a zygote into an adult

Answer 2

cell divisions, migration, and apoptosis

Question 3

what is important to the study of specific cell types because it goes to its origin and leads to a better understanding of its development

Answer 3

fate maps

Question 4

fate maps also provide a common method for ___ of embryo development and beyond in a variety of species

Answer 4

comparisons

Question 5

for what species have fate maps been constructed?

Answer 5

select group of organisms- sea squirts, sea urchins, frogs

• for organisms with transparent, easily accessed embryos

Question 6

fate maps generation requires extensive and careful ______ from zygote to adult

Answer 6

analysis of every cell division

Question 7

only in this organism is there a complete fate map determined through microscopic examination of every cell division

Answer 7

C. elegans

Question 8

are partial fate maps still generated for many organisms and are very useful?

Answer 8

yes

Question 9

one of the first fate maps was for the ___

Answer 9

sea squirt (Styela partita)

• the embryos are transparent enough to be viewed with
  a light microscope

Question 10

the cytoplasm in the embryo of sea squirts contains differentially ___ regions that can be used to follow the fate of cells during development

Answer 10

pigmented

Question 11

fate maps can be made of specific ___ or ___

Answer 11

organs or tissues

Question 12

what do you need for a fate map?

Answer 12

1- a complete understanding of the development of the organism or tissue you want to map
- many many hours, and microscopic examination

2- series of tools to track cells as they divide and develop into tissues and organs

Question 13

are developmental observations to yield a fate map a more recent event?

Answer 13

no, several researchers began anatomic observation of embryos in 18th century to trace cell fates

(comparitive anatomy began before this, but needed microscopes to help)

Question 14

name 5 fate mapping tools

Answer 14

1- vital dyes (dyes that stain cells, but do not kill them)
2- fluorescence dyes
3- genetic markers (molecular markers: reporter genes, GFP)
4- physical destruction of cells (needles, laser ablation, molecular targeting of cell death)
5- molecular tools (mutation or RNAi analysis, transcriptomic or proteomic of specific cells or tissues)

Question 15

describe fate mapping with a natural pigment

Answer 15

mapping the fate of pigment in cytoplasm

• the yellow pigment is distributed asymmetrically in the egg & zygote

“yellow-crescent” of single-celled embryo
—>
the cells containing yellow pigment become muscle

Question 16

describe fate mapping using a fluorescent dye

Answer 16

dye: fluorescein-dextranamine (stable high MW) which fluoresces green under UV light

• follow the fate of the injected cell and its progeny

Question 17

describe fate mapping using molecular markers

Answer 17

marker (GFP) with no promoter is inserted randomly into genome…when near an enhancer, it becomes expressed in a manner controlled by that enhancer (cell lineage specific)

Question 18

describe physical destruction of cells for fate mapping

Answer 18

what was first done crudely with a needle can now be done very precisely with a laser or using gene specific targeting of cells for death, regardless the results are the same

Question 19

name 5 methods of physical manipulation of embryos

Answer 19

shaking
microsurgery
separation
removal of parts
squashing