Download presentation
Presentation is loading. Please wait.
Published byAmbrose Barker Modified over 9 years ago
1
MCB 186 CIRCADIAN BIOLOGY The cellular-molecular mechanism of the circadian clock CLOCK MUTANTS Lecture #4 October 18, 2006 J. W. Hastings
2
WHAT DO YOU DO WITH A MUTANT? Isolate the gene responsible. How do you map a gene? Clone the gene? How do you find out what the gene does? CIRCADIAN CLOCK MUTANTS WHAT PHENOTYPES to SELECT?
3
The first CLOCK MUTANTS: the DROSOPHILA period (per) GENE WILD TYPE ~24 h PER short ~ 18 h PER long ~ 28 h
4
CIRCADIAN CLOCK GENES 1) DROSOPHILA per ( PERIOD ) tim ( TIMELESS ) 2) NEUROSPORA frq ( FREQUENCY ) prd ( PERIOD ) 3) CYANOBACTERIA kai ( CYCLE IN JAPANESE ) 4) HAMSTER tau ( PERIOD ) 5) MOUSE clk ( CLOCK ) per1 ( PERIOD ) 6) ARABIDOPSIS (CCGs) toc1 (TIMING OF CAB) lhy (LATE ELONG HYPOCOTYL) cca1 (CIRC CLOCK ASSOCIATED)
5
The clock controls an overt rhythm in developmental potential in Neurospora. movie courtesy of Van Gooch
6
FRQ (frequency) GENE IN NEUROSPORA Dunlap et al
7
CIRCADIAN CLOCK BIOCHEMICAL FEEDBACK CYCLE-NEUROSPORA DUNLAP, 1999
8
LIGHT CAUSES PHASE SHIFTS BY INDUCTION OF FRQ mRNA CROSTHWAITE, LOROS & DUNLAP, 1995
9
POSTULATED FEEDBACK LOOPS IN REGULATION OF CLOCK GENE EXPRESSION
10
CORE CLOCK COMPONENTS IN FEEDBACK LOOPS OF 3 SYSTEMS
11
The cyanobacterial clock Kai genes
12
LUCIFERASE as a REPORTER for CIRCADIAN GENE EXPRESSION: INSERTED DOWNSTREAM from a PROMOTER
13
Cyanobacterial in vivo Rhythm with Bacterial Luciferase as a Reporter Luminescence Kondo, Johnson Golden et al., 1993, PNAS
14
DARK PULSE PHASE SHIFTS IN CYANOBACTERIA KONDO ET AL 1993
15
BACTERIAL CIRCADIAN PERIOD is TEMP-COMPENSATED Q 10 ~ 1.1
16
BACTERIAL COLONIES EXPRESSING BIOLUMINESCENCE Day phase Night phase Code numbers
17
LUCIFERASE REPORTER RANDOMLY INSERTED IN FRONT OF PROMOTERS IN BACTERIA. ABOUT 800 LUMINOUS COLONIES ISOLATED ALL EXHIBITED CIRCADIAN RHYTHMS ACROPHASES NOT ALL THE SAME Liu et al., Circadian orchestration of gene expression in Cyanobacteria. (1995) Genes & Develop. 9: 1469-1478
18
CLASSES OF CLOCK-CONTROLLED GENES IN CYANOBACTERIA LIU,1995
19
CLASSES OF CLOCK-CONTROLLED GENES IN CYANOBACTERIA LIU,95
20
PERIOD MUTANTS OF CYANOBACTERIA KONDO ET AL.1995
21
CYANOBACTERIA ARHYTHYMIC & AMPLITUDE MUTANTS KONDO 1995
22
PERIOD VARIATION OF INDIVIDUAL CYANOBACTERIA MUTANT CLONES KONDO ET AL.1995
23
KAI genes in SYNECHOCOCCUS and MUTANT MAPPING Ishiura et al 1998 Science 281: 1519-1523 All of ~200 mutants isolated map to this gene cluster
24
PHENOTYPES OF KAI GENE INACTIVATIONS Ishiura et al 1998 Science 281: 1519-1523
25
EXPRESSION OF KAI GENE CONSTRUCTS Ishiura et al 1998 Science 281: 1519-1523
26
EXPRESSION and ROLES of KAI genes
27
Cyanobacterial Clockworks Model -1998 Ishiura et al 1998 Science 281: 1519-1523
28
POSTULATED FEEDBACK LOOPS IN REGULATION OF CLOCK GENE EXPRESSION
29
EVIDENCE THAT TRANSCRIPTION and TRANSLATION are not NECESSARY for CIRCADIAN OSCILLATIONS IN CYANOBACTERIA Tomita, Nakajima, Kondo & Iwasaki (2005) No transcription-translation feedback in circadian rhythm of KaiC phosphorylation Science 307: 251-254
30
NO RHYTHM OF kaiA or kaiBC mRNAs in DD Tomita, Nakajima, Kondo & Iwasaki (2005) No transcription-translation feedback in circadian rhythm of KaiC phosphorylation Science 307: 251-254
31
NO RHYTHM OF KaiC PROTEIN in DD Tomita, Nakajima, Kondo & Iwasaki (2005) Science 307: 251-254
32
RHYTHM OF KaiC PROTEIN PHOSPHORYLATION in DD Tomita, Nakajima, Kondo & Iwasaki (2005) Science 307: 251-254
33
Period Temperature Compensation of in vivo Rhythm of KaiC Phosphorylation in DD Tomita, Nakajima, Kondo & Iwasaki (2005) No transcription-translation feedback in circadian rhythm of KaiC phosphorylation Science 307: 251-254
34
Period of phosphorylation rhythm corresponds to mutant period Tomita, Nakajima, Kondo & Iwasaki (2005) Science 307: 251-254
35
Model for the posttranslational oscillator coupled with TTO Tomita, Nakajima, Kondo & Iwasaki (2005) No transcription-translation feedbackin circadian rhythm of KaiC phosphorylation Science 307: 251-254
36
RHYTHM of Kai C PHOSPHORYLATION in a SOLUTION CONTAINING only ATP plus Kai A, B and C Nakajima, M. et al Kondo, T. (2005) Reconstitution of circadian oscillation of KaiC phosphorylation in vitro Science 308: 414-415
37
IN VITRO CIRCADIAN RHYTHM KaiC PHOSPHORYLATION Nakajima, M et al Kondo, T (2005) Reconstitution of circadian oscillation in vitro Science 308: 414-415
38
In vitro phosphorylation rhythm is temperature compensated Nakajima, M et al Kondo, T (2005) Reconstitution of circadian oscillation in vitro Science 308: 414-415
39
In vitro phosphorylation rhythm is temperature compensated Nakajima, M et al Kondo, T (2005) Reconstitution of circadian oscillation in vitro Science 308: 414-415
40
Period of in vitro P-oscillation corresponds to mutant period Nakajima, M et al Kondo, T (2005) Reconstitution of circadian oscillation in vitro Science 308: 414-415
41
Period of in vitro P-oscillation corresponds to mutant period Nakajima, M et al Kondo,T (2005) Reconstitution of circadian oscillation in vitro Science 308: 414-415
42
HOW THE TWO COMPONENTS MAY RELATE
43
LBP mRNA DOES NOT CYCLE IN GONYAULAX
44
THE SINGLE CELLED ALGA ACETABULARIA MEDITERRANEA
45
2 ACETABULARIA RHYTHMS:O 2 EVOL & CHLOROPLAST MOVEMENT SCHWEIGER ET AL, 1981
46
NUCLEUS IS IN ROOT- RHYTHM CONTINUES WHEN CUT OFF BUT A NEW NUCLEUS GRAFTED ON CONFERS ITS PHASE TO HOST
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.