Window of observation (mitotic cell) After pulsing, no labeled mitotic cell was observed. When will you see the first labeled mitotic cell? Why then the number of labeled mitotic cell increase with time? Why the number of labeled mitotic cell decrease then?

During embryo development, no checkpoint activity to work. Two possibilities: 1, there is a suppressed checkpoint machine Who is the suppressor? And how to relieve the suppression? 3, there is no checkpoint machine there When and how the checkpoint machine resume activity?

1, Dosage of transcribed DNA correlates with degree of replication checkpoint activity. 2, Time-resolved RNA Pol II ChIP-seq over the course of zygotic genome activation. 3, Sites of stalled DNA replication overlap with transcribed genomic loci. 4, Reducing zygotic transcription eliminates a genetic requirement for the checkpoint

Zygotic genome activation triggers the DNA replication checkpoint at the midblastula transition Cell. 2015 Mar 12;160(6):1169-81.

Chk1 Inhibition of the Replication Factor Drf1 Guarantees Cell-Cycle Elongation at the Xenopus laevis Mid-blastula Transition. Developmental Cell 42, 82–96. 2017

AB divides first, followed by P1 about 2 min later. Why?

An example of DNA damage–independent utilization of the ATR checkpoint An example of DNA damage–independent utilization of the ATR checkpoint. This 2-min delay is controlled in part through differential activation of the S phase checkpoint in the P1 cell. Developmental checkpoint activation in the early embryo requires the C. elegans homologues of ATR (atl-1) and Chk1 (chk-1). When asynchrony is reduced, through loss of chk-1, the germ line fails to develop and the animal is sterilized. Silencing requires rad-2, gei-17, and the polh-1 translesion DNA polymerase, which suppress replication fork stalling and thereby eliminate the checkpoint-activating signal from DNA damage.  Checkpoint silencing during the DNA damage response in Caenorhabditis elegans embryos J Cell Biol. 2006 ; 172: 999–1008.

Is competent state of cell cycle real in vivo? Stem cell in vivo is in a quiescence state (Go). When it is activated by injury and enters the cell cycle, do they have competent state and then progression into the cell cycle?

mTORC1 controls the adaptive transition of quiescent stem cells from G0 to GAlert Nature  510, 393–396 ( 2014)

HGFA Is an Injury-Regulated Systemic Factor that Induces the Transition of Stem Cells into GAlert. Cell Rep. 2017; 19: 479-486

Why HSN neuron is missing (apoptosis) in egl-1 mutant? What egl-1 gene doing? The C. elegans Protein EGL-1 Is Required for Programmed Cell Death and Interacts with the Bcl-2–like Protein CED-9 Cell 93, p519–529, 1998 Why HSN neuron is missing (apoptosis) in egl-1 mutant?

The TRA-1A Sex Determination Protein of C The TRA-1A Sex Determination Protein of C. elegans Regulates Sexually Dimorphic Cell Deaths by Repressing the egl-1 Cell Death Activator  Cell 98, p317–327, 1999

Quiz 3-12-2018 (quiz 2 to 7 are for the assigned research paper) 1, What is the biochemical assay Dr. Wang designed to isolate and reconstitute cellular components which can activate Ced3 protein in vitro? 2, Is c-myc a cell cycle regulated gene? 3, How to estimate % of cells in S phase when Rat-1/myc cells grow in 0.1% of serum and what is the result? 4, Is Rat-1 a primary cells? 5, In Table one, cotransformating and apoptosis inducing activities of Myc mutants were compared. What is the cotransforming acitivity? 6, Is myc-induced apoptosis a cell cycle dependent event? What experiment results support your answer?   Bonus 7, what is the question you are most interested after reading this paper and how to answer your question by experiment?

Quiz 3-12-2018 (quiz 2 to 7 are for the assigned research paper) 1, What is the biochemical assay Dr. Wang designed to isolate and reconstitute cellular components which can activate Ced3 protein in vitro?

Induction of apoptotic program in cell-free extracts: requirement for dATP and cytochrome c. Cell.1996 Jul 12;86(1):147-57.

Quiz 3-12-2018 (quiz 2 to 7 are for the assigned research paper) 2, Is c-myc a cell cycle regulated gene?

Quiz 3-12-2018 (quiz 2 to 7 are for the assigned research paper) 3, How to estimate % of cells in S phase when Rat-1/myc cells grow in 0.1% of serum and what is the result?

Flow cytometry

Quiz 3-12-2018 (quiz 2 to 7 are for the assigned research paper) 4, Is Rat-1 a primary cells?

Quiz 3-12-2018 (quiz 2 to 7 are for the assigned research paper) 5, In Table one, cotransformating and apoptosis inducing activities of Myc mutants were compared. What is the cotransforming acitivity?

Quiz 3-12-2018 (quiz 2 to 7 are for the assigned research paper) 6, Is myc-induced apoptosis a cell cycle dependent event? What experiment results support your answer?  

Quiz 3-12-2018 (quiz 2 to 7 are for the assigned research paper) 7, what is the question you are most interested after reading this paper and how to answer your question by experiment?  

Myc induced apoptosis and oncogene addiction in vivo

How to intervene apoptotic pathway by small molecules? To prevent apoptosis in neuron or to enhance apoptosis in cancer cells!

Targeting Apoptosis via Chemical Design: Inhibition of Bid-Induced Cell Death by Small Organic Molecules Chemistry & Biology, 11, 1107–1117, 2004

Cell Death and Differentiation (2018) 25, 27–36 The BCL-2 arbiters of apoptosis and their growing role as cancer targets Cell Death and Differentiation (2018) 25, 27–36

Physiological role of senescence cell Cellular senescence and the senescent secretory phenotype: therapeutic opportunities The Journal of Clinical Investigation 123: 966; 2013

Tissue damage and senescence provide critical signals for cellular reprogramming in vivo. Science 354; 1020; 2016

Is cell cycle control an evolutional conserved mechanism?