| 6564614116 | Fate of different parts of neural tube:
most of neural tube becomes:
rest of neural tube differentiates into: | most: spinal column
rest of neural tube: forebrain, midbrain, hindbrain | | 0 |
| 6564615527 | Forebrain is called the ?
divides into 2 parts: | Prosencephalon
-telencephalon: cerebral cortex, hippocampus
-diencephalon: thalamus and hypothalamus | | 1 |
| 6564617409 | midbrain is called the ? | mesencephalon: superior and inferior colliculi | | 2 |
| 6564617895 | hindbrain is called the? | metencephalon: pons and cerebellum | | 3 |
| 6564621040 | In regards to development, pattern refers to:
A. the proteins produced by an individual cell
B. The stages of development through which an organism proceeds
C. The arrangement of regions of the body of an organism
D. The process of differentiation of specific cell types | C. The arrangement of regions of the body of an organism | | 4 |
| 6564622421 | in a mature spinal cord, neurons involved in processing sensory INPUT are located where? | dorsal half of spinal cord. | | 5 |
| 6564623621 | in mature spinal cord, neurons involved in motor OUTPUT are located where? | ventral half of spinal cord | | 6 |
| 6564624131 | Spearmann organizer is involved in specifying ? | anterior and dorsal part of embryo
"transformer" that can posteriorize neural tissue | | 7 |
| 6570674506 | Two signals from organizer region are released:
initial signal:
second signal:
this is called the "activator-transformer" hypothesis | initial signal from organizer causes ECTODERM cell to develop anterior characteristics "activator"
second signal required to transform portion of neural tissue into hindbrain and spinal cord "transformer | | 8 |
| 6570676895 | neural inducers such as (3) mainly produce anterior structures | noggin, chordin and follistatin | | 9 |
| 6570678198 | deletion of neural inducers such as noggin/chordin double knockout resulted in ? | headless mice but animals still have posterior tissue | | 10 |
| 6570679409 | Three molecules identified to contribute to "transformer" activity | Wnt
Retinoic acid
FGFs | | 11 |
| 6570709861 | What does Wnt control? | body axis patterning, cell fate specification, cell proliferation, and cell migration
-required for proper formation of important tissues including bone, heart and muscle | | 12 |
| 6579841631 | Wnts are expressed in ? manner | gradient manner | | 13 |
| 6579843314 | What would injection of a Wnt inhibitor and BMP inhibitor do to embryo? | cause growth of a new head | | 14 |
| 6579846298 | what would injection of anti-dkk (naturally occurring Wnt inhibitor) antibody do? | reduce head development | | 15 |
| 6579850417 | what are FGFs?
FGFs are expressed in a high-_________ and low- ___________ gradient | -they are neural inducers
-expressed in high POSTERIOR-low ANTERIOR | | 16 |
| 6586659025 | higher the FGF dose, _______ posterior genes expressed | MORE | | 17 |
| 6586663187 | Are there other genes that induce formation of posterior structures besides FGF? | homeobox (Hox) gene | | 18 |
| 6586667202 | Hox genes are transcription factors that control what in fly body? | segmentation of fly body | | 19 |
| 6586678190 | Hox genes are expressed in what 2 places? | spinal cord and hindbrain | | 20 |
| 6586680614 | hindbrain is divided into segments called ____ and is organized in segmental units by ___. | rhombomeres
how genes | | 21 |
| 6586684454 | rhombomeres are a set of motor neurons that control ? | facial muscles
-each rhombomere gives rise to unique set of motor neurons that control different muscles in the head | | 22 |
| 6586689854 | Hindbrain gives rise to (2) | sensory ganglia and motor nuclei | | 23 |
| 6586720735 | what happens if you KO all Hox genes? | - transform all posterior rhombomeres into r1 | | 24 |
| 6586754930 | how gene expression in hindbrain is regulated by ? which is expressed in ? adjacent to organizer region | retinoic acid
mesodermal cells | | 25 |
| 6586777732 | if there is a low exposure of retinoic acid can cause changes in pattern of ____ gene expression in the _________. | Hox gene
hindbrain | | 26 |
| 6586780844 | retinoic acid is a powerful ______. It is made by the ___________, and expression is increased more _________. Retinoic acid is crucial for _________ expression | retinoic acid is a powerful TERATOGEN. It is made by the MESODERM, and expression is increased more POSTERIORLY. Retinoic acid is crucial for HOX gene expression. | | 27 |
| 6586827647 | Otx2 gene required for development of _________ and _________. | forebrain and midbrain (ANTERIOR side of brain) | | 28 |
| 6586829267 | Gbx2 gene is required for _________. | posterior hindbrain (posterior side of brain) | | 29 |
| 6586841346 | What do Otx2 and Gbx2 genes do to each other? | co-repress each other to form sharp boundaries between mid-hindbrain boundary | | 30 |
| 6586852813 | what would happen if you deleted Otx2 gene? | headless embryo | | 31 |
| 6586932248 | forebrain is made up of 3 things: | cerebral cortices
basal ganglia
hypothalamus and thalamus | | 32 |
| 6586946923 | what molecules are expressed in the midbrain/hindbrain region of the brain? | Engrailed-1, Wnt1 and Fgf8 | | 33 |
| 6586950921 | What happens when you KO either Engrailed-1, Wnt1, or Fgf8? | elimination of cerebellum and midbrain | | 34 |
| 6586956510 | Can misimpression of Engrailed-1, Wnt1 or Fgf8 induce ectopic structures? | yes!
ectopic midbrain/hindbrain structure | | 35 |
| 6586972371 | Early in development of midbrain/hindbrain what 2 genes are activated? What genes are activated later in development as the forebrain gets bigger | Early in development: Otx2 and Gbx2
Later in development: Wnt (with Otx2-forebrain)and Fgf8 (with Gbx2-hindbrain) | | 36 |
| 6586992425 | as forebrain (prosencephalon) grows, it develops distinct regions called? | prosomeres
(similar to rhombomeres in hindbrain) | | 37 |
| 6587003646 | prosomeres have patterns of gene expression, in particular (2) | emx genes and pax genes | | 38 |
| 6587007885 | pax6 gene expression gives rise to what region? | eyes | | 39 |
| 6587013494 | homozygous mutant of Pax6 gene:
heterozygous mutant of Pax6 gene: | homozygous: no eye formation and other brain defects
heterozygous: no iris and other defects | | 40 |
| 6587036501 | 2 genes expressed in a gradient dependent manner in the cortex are ? | emx2 (posterior) and pax6 (anterior) genes | | 41 |
| 6587046022 | when emx2 gene is deleted what happens to cortical areas? | anterior structures are more prominent | | 42 |
| 6587049533 | when pax6 gene is deleted, what happens to cortical areas? | posterior structures more prominent | | 43 |
| 6587057569 | FGF expression in cortex (cortical) occurs ________ pole, and BMP expression in cortex occurs in _______ pole | FGF = anterior pole
BMP = posterior pole | | 44 |
| 6587071085 | top and bottom of neural tube are different:
bottom is called the ________
top is called the ________. | bottom = floor plate
top = roof plate | | 45 |
| 6587079275 | neural tube: bottom is the FLOOR PLATE: what does it give rise to? | ventral part of spinal cord = gives rise to MOTOR neurons | | 46 |
| 6587083668 | neural tube: top is ROOF plate: what does it give rise to? | dorsal part of spinal cord = gives rise to SENSORY neurons
also produces neural crest | | 47 |
| 6587100932 | if you remove the notochord (located closest to floor plate) what would happen? | no floor plate being formed = no motor neurons form | | 48 |
| 6587105869 | if you transplant a notochord (located closest to floor plate) what would happen? | ectopic floor plate being formed = another set of motor neurons form | | 49 |
| 6587117054 | mesoderm cells and notochord (later in development) provide 2 types of inductive signals to form floor plate: | - locally (short)acting signal that induces formation of floor plate
-longer (long)signal that induces differentiation of both motor neurons and ventral interneurons | | 50 |
| 6587132997 | short and long-range signaling of notochord are mediated by protein ? | sonic hedgehog (SHH) | | 51 |
| 6587135316 | what does SHH (sonic hedgehog) do? | induce differentiation of floor plate cells, motor neurons and ventral interneurons | | 52 |
| 6587140157 | what happens when shh signaling is eliminated? | blocks notochord's ability to induce all cell types generated in ventral neural tube.
= necessary and sufficient to induce differentiation of cells in ventral neural tube | | 53 |
| 6587162332 | besides induction of differentiation of cells of ventral neural tube, shh signaling is also found to be necessary and sufficient for? | floor plate formation and ventral spinal cord specification | | 54 |
| 6587169002 | concentration of shh is high _______ and low ________ | ventrally
dorsally | | 55 |
| 6587179434 | Is shh a morphogen? | yes
higher concentration of shh = more ventral | | 56 |
| 6587184368 | How does a shh determine the fate of many different cell types in the ventral half of CNS? | SHH not only acts as an inducer but ALSO as a morphogen | | 57 |
| 6587186933 | morphogen | type of inducer signal that can direct different cell fates at different concentrations | | 58 |
| 6587198962 | low [shh] exposed to ventral neural tube cells will differentiate into | ventral interneurons | | 59 |
| 6587200429 | high [shh] exposed to ventral neural tube cells will differentiate into ________.
further increase of shh expression will induce _______. | motor neurons.
further increase = induces floor plate cells | | 60 |
| 6587210969 | How is diffusion of SHH controlled? | shh is synthesized as inactive precursor, when cleaved = active | | 61 |
| 6587216439 | disrupting or mutations in shh signaling pathway leads to ? | variety of disease, mutation in neurological defects, spina bifida, limb deformities, and cancer | | 62 |
| 6587231150 | Shh is also expressed in forebrain, what does this do? | helps wil formation of midline (gives symmetry) 2 eyes and 2 hemispheres | | 63 |
| 6587246324 | What are some consequences of reduced shh signaling in forebrain? | holoprosencephaly (not having left/right cerebral hemisphere) or cyclopean (having 1 eye | | 64 |
| 6587251462 | What is the most dorsal section of neural tube? | neural crest | | 65 |
| 6587255190 | what do the neural crest cells form when the migrate? | depends on positioning | | 66 |
| 6587263013 | what specifies the neural crest? | the ectoderm | | 67 |
| 6587268169 | what molecule is produced by the ectoderm and is it capable of inducing neural crest? | BMP! | | 68 |
| 6587272017 | Is BMP a morphogen? | yes!
more BMP = more dorsal fate | | 69 |
| 6587278912 | ventral patterning is controlled by what protein? | shh (concentration gradient) | | 70 |
| 6587282617 | dorsal pattern is controlled by what? | BMP | | 71 |
| 6587290005 | dorsal-ventral specification of neural tube requires signaling by?
A. shh from notochord
B. BMP4 from floor plate
C. FGF from midbrain-hindbrain
D. Oct4 from inner cell mast | A. shh from notochord | | 72 |
| 6587293783 | where does neural plate first begin to fold into a tube?
A. rostral end
B. Middle
C. caudal end | B. Middle | | 73 |
| 6587293784 | Dorsal-ventral specification of the neural tube requires signaling by ______.
A. Shh from the notochord
B. BMP4 from floor plate
Fgf8 from the midbrain-hindbrain boundary
D. Oct4 from inner cell mass | A. Shh from the notochord | | 74 |
| 6587299330 | Lack of dietary supplement folate can lead to birth defects. Where in the embryo is folate most required for normal development?
A. rhombomeres
B. notochord
C. neural tube
D. primitive streak | C. neural tube | | 75 |
