Model Organism for Cell division•Eukaryote

•Similar to higher organisms

•Early embryo • Size• Transparent• Stereotype cell division

First Two rounds of cell Division in Wild Type C. Elegans

Precise Cell Division Timing

•Cell cycle

•Early embryogenesis

•Genes required for DNA replication• DNA polymerase machinery• Activation of DNA

replication• Monitor of DNA replication

DNA S

ynth

esis

Goal of the projectIdentify genes that are involved in DNA

replication during the cell cycle

Approach- utilize cell division mutantsExecute DNA replicationActivate DNA replication

Temperature Sensitive, Embryonic Lethal Mutant

26˚C

15˚C Functional gene

Non-functional gene

Cell progression in early cell division(div mutant /P1 delay)

Sandra Encalada, 2000

Wild Type Eu2100 or1232

P1 Delay

Sandra Encalada, 2000

~ 800 TS-EL

13 confirmed P1 delay

25 candidates

5 strains

5 strains

or493

or1232

or1332or1579

or1295

The Process in Identifying the Gene

Phenotype strain

Outcross mutant to wild

type Outcross mutant to polymorphic strain for mapping and

gene identity

Present WorkIdentify strain that are P1 delay

•Phenotype the strain•Nomarski DIC •3-5 movies

Results 2 strains are mildly P1 delay

or1332or1579

2 strains are P1 delayor1232or1579

1 strain is mitotic spindle defective (spd)or493

P1 Delayor

1232

or

1579

WT

(N

2)

0’’

0’’

0’’

24.1’

50.8’

29.6’

38.2’

41.4’

34.4’

Mitotic spindle defective (spd)W

T (

N2) 14.2’

0’29.6’

or4

93

21.7’17.3’ 33.4’

0’ 11.9’

14.2’

The Process in Identifying the Gene

Phenotype strain

Outcross mutant to wild typeOutcross mutant to

polymorphic strain for mapping and

gene identity

Present Work and Future GoalsPhenotype strain

Outcross strain to WT WT

F2

Lin-2 or1232

Lin-2

F1Lin-2 or1232

or1232

Lin-2 or1232

Lin-2 or1232Lin-2 or1232

Future direction

Phenotype strain

Outcross mutant to wild

type Outcross mutant to polymorphic

strain for mapping and gene

identity

SummaryPhenotype

3-5 DIC movies of each strainP1 delay: or1232 and or15792 strains were mildly delayed1 strain was found to be mitotic spindle defective

The strains confirmed to be P1, out-crossing to wild type is carried out.

In the future, desired outcross mutant strain will be outcross to polymorphic strain for WGS.

AcknowledgementsBruce Bowerman –-PIJoshua Lowry –MentorPeter, Adam, SPURmiesReza--Post-DocChien Hui–- Lab ManagerAmy--Graduate studentSean– Post DocAvaSophieDianaNSF REU BIO 1063144

THEUndergraduates

Thank you.