-broken ends are rejoined by DNA ligation (lose portions of chromosome)
- loss of nucleotides
-quick and dirty solution
- exchange of DNA strands between a pair of homologous duplex DNA sequences
- can repair double stranded breaks accurately without loss or alternation of nucleotides at site of repair
- looks at other chromosome, scan to recognize what portion is missing or similar
does homologous recombination lose diversity?
ATM/ATR kinase protein
transducing DNA damage signals to checkpoint control proteins
kinase and phosphatase
what two enzymes help regulate the cell cycle
what is between M and S?
what is between S and M?
gap phases (G1 and G2)
allows time for growth of the cell
resting state of no replication
- can use DNA binding fluorescent dyes: reveals condensation of chromosomes in mitosis
- antibodies against microtubules
artificial thymidine analog
- can incorporate into DNA during DNA replication
- rapid analysis of a alrge number of cells
- measures DNA content in a cell population and sorts the data
late in G1
- is environmental favorable?
- controls system triggers early mitotic events that lead to chromosome alignment on the mitotic spindle in metaphase.
- is all DNA replicated?
- is environment favorable?
- control system stimulates sister-chromatid separation leading to completion of mitosis and cytokinesis
- are all chromosomes attached to the spindle?
cyclin dependent kinase (CDK)
-members of a family of kinases
- rise and fall throughout the progression of the cell cycle
- cyclical changes in phosphorylation of intracellular proteins
- CDK is dependent on this
- made and destroyed though the cell cycle
activates CDKs late in G1
- levels fall in S phase
- binds CDKS after progression through start
- stimulate chromosome duplication
- remain elevated until mitosis
- activates CDKS that stimulate into mitosis at G2/M transition
- fall in mid-mitosis usually around metaphase/anaphase