Chapter 8 (nematodes) Flashcards
C. elegans are small (__mm), free-living (_______) soil nematode
1
non-parasitic
Who was the scientist that studied C. elegans?
Sydney Brenner
- won nobel prize in 2002
- also know that C. elegans are super easy to study (full genome and cell lineage)
C. Elegans are _______ and fertilization occurs within a single individual
hermaphrodites
A C. elegan egg is fertilized as it roles through the _______
spermatheca
- contains mature sperm
C. Elegan sperm is _______ and _______
round and unflagellated
in C. Elegans, polyspermy is prevented by the rapid formation of a _______ of _______ after fertilization
cuticle of chitin
in C. Elegans, the fertilized egg undergoes cleavage divisions and is extruded from the _______
vulva
C. Elegan undergo _______ cleavage
rotational holoblastic
each early division is asymmetrical and produces: (2)
1) founder cell
- anterior
2) stem cell
- posterior
A _______ produces differentiated descendants (AB, E, MS, C, D)
founder cell
A _______ always divide meridionally to produce an anterior founder cell and a posterior stem cell that will continue the stem cell lineage
stem cell
Anterior-posterior axis is determined by the position of the sperm _______
pronucleus
The anterior and posterior axis are determined before the _______ cell division
first
the Oocyte has _______ proteins arranged in the cytoplasm that aid in A-P axis division
PAR proteins
(partitioning-defective)
_______ and _______ are uniformly distributed and interact with PKC-3 protein kinase
PAR-3 and PAR-6
PKC-3 phosphorylates ________ and _______, this action restricts them to the internal cytoplasm
PAR-1 and PAR-2
Sperm centriole initiate cytoplasmic movements within the oocyte cytoplasm which pushes the _______ to the nearest end
male pronucleus
- posterior end
Male pronucleus in the posterior end locally protect _______ from phosphorylation, allowing them into the cortex nearest the centrosome
PAR-2 (binded to PAR-1)
Once PAR-1 is in the cortex cytoplasm, it phosphorylates _______ causing it and its binding partner _______ to leave the complex
PAR-3
PKC-3
The metaphase plate is closer to the _______ and divides the egg into two cells with different cytoplasmic determinants
posterior
In A/P axis formation, the anterior cell contains ________ and _______
PAR-3
PAR-6
(Founding cell)
In A/P axis formation, the posterior cell contains ________ and _______
PAR-1
PAR-2
(stem cell)
The dorsal/ventral axis is specified at the _______ division
2nd
What are the 2 cells that are formed when AB divides in the 2nd division?
1) ABa
2) ABp
_______ cell specifies the dorsal side (top)
ABp
- moves over top of ABa and EMS cells
_______ forms the muscle and gut = ventral side
EMS
In dorsal/ventral axis formation, _______ on the surface of P2 binds to _______ on ABp but not on ABa since they do not touch
APX-1 (notch family)
GLP-1 (delta homolog)
- this is juxtracrine signaling
The R/L axis is specified at the ____-cell stage
12
the R/L axis is specified by asymmetric signaling by _______ which activates _______ in the cells it contacts
Delta
Notch
- mainly MS contacting ABa
The P1 cell and its descendants (MS, E, C, D) are _______ specified by the presence of 3 transcription factors
autonomously
What are the 3 transcription factors that autonomously specify P1 cell and its descendants?
1) SKN-1
2) PAL-1
3) PIE-1
P1 TF
_______: TF that controls the development of pharyngeal structures
SKN-1
- skin excess
P1 TF
_______: TF that specifies muscle development
PAL-1
P1 TF
_______: TF that is required for germline fate
PIE-1
AB cell and its descendants are _______ specified by their interaction with P1 lineage cells
conditionally
P2 cell instructs the EMS daughter closest to it to become the _______ cell, specifying the _______ from the _______
E
Endoderm from the Mesoderm
P2 produces a _______ paracrine signal that is received by a cell surface receptor _______, on the EMS cell
MOM-2
MOM-5
In C. elegans, gastrulation starts at the _____ cell stage just after the generation of the P cell
26
Daughters of the _______ migrate to the center of the embryo
E cell
_____ moves through the blastopore and forms the germ line cells
P4
_____ cell migrates inward and will form the mesoderm
MS
Initial worm stage stretches out with 558 somatic cells, and after 4 molts the mature _____ somatic cell adult is produced
959
