Chapter 10 tunicates Flashcards
The tunicate is an _______ _______
- what kind of animal?
invertebrate chordate
Tunicate larva have a _______ and _______, however these both degenerate as it transitions into an adult
notochord
dorsal nerve cord
Tunicates undergo _______ cleavage
bilateral holoblastic
Anterior/posterior and Dorsal/ventral axis are determined by cytoplasmic determinants _______ the first division
before
1st division in tunicates is _______ and it establishes _____ axis
meridional
R/L
2nd division _______ but not through center and creates a small and large blastomere on both sides
meridional
- creates anterior cells (A/a cells) and posterior cells (B/b cells)
During the second division, which cell is larger anterior or posterior?
anterior
3rd-6th division are all _______, each generating a larger _____ cell and smaller _______ cell
asymmetrical
anterior
posterior
Early blastomeres are specified _______ by acquiring a specific piece of the cytoplasm
autonomously
_______ stimulates microtubule and Ca2+ driven cytoplasmic rearrangments
sperm entry
Cytoplasmic fates:
_______ = tail muscles of tunicate larva
yellow crescent
Cytoplasmic fates:
_______ = ectoderm
clear cytoplasm
Cytoplasmic fates:
_______ = mesodermal cells
yellow cytoplasm
Cytoplasmic fates:
_______ = endoderm
slate grey inclusions
Cytoplasmic fates:
_______ = neural tube and notochord
light gray cells
The notochord, brain, heart, and mesenchyme all form through _______ interactions
inductive
In notochord development, _______ transcription factor from the endoderm stimulates _______ signaling
β-catenin
FGF
In notochord development, _______ is a TF that activates notochord-specific genes
brachyury
How is brachyury activated? (4 steps)
β-catenin to FoxD to FGF signaling to Brachyury
_______ is one of the genes involved in shaping the forming notochord activated by Brachyury TF
Prickle
_______ activates muscle forming genes in tunicates
Macho-1
Macho-1 activates _______, which supresses _______ and thus prevents notochord formation
Snail
Brachyury
______ signaling from the endoderm causes different effects in the presence or absence of Macho-1
FGF
In deuterostomes, the blastopore becomes the _______
anus
- second mouth
Tunicate gastrulation:
1) the endoderm _______ into the center of the embryo
2) the mesoderm _______ over the lips of the blastopore and moves over the basal surfaces of the ectodermal cells deep into the embryo
3) Ectodermal cells are flattened and _______ to cover the entire embryo
1) invaginates
2) involutes
3) epibolize
When the endoderm invaginates, anterior blastopore lips form _______
notochord cells
When the endoderm invaginates, posterior blastopore lips form _______
tail muscle cells
When the endoderm invaginates, lateral blastopore lips form _______
mesenchyme cells
