, .

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.

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.

, . 292

2

293

:

1729 deMairan , .

, .

Brassica rapa 20 5 294

295 - -

,

Circadian rhythm, Circadian clock

Latin: Circa = , ; dies = Franz Halberg, 1959 296

6

- (, SCN) , .

, , . 297

298

299

~ 700 m

-

1 2910

100 m 2911

100

100 1 2912

(, SCN) , .

: . 2913

012345()

1

1

100 m 2914

29

()15

. , .

: ? 2916

: 1) , 2) , 3)

2917

012345()

2918

Per,* Per*

Per 2919

24 , , , , .

2920

, , . . , .

, .

2921

PER2::LUC , 2922

29

()23

2924

2925

2926

2927

2928

, . , , .

http://scisne.net/a-1599

, () . , , () , . - . 1- 1- , . , , , , , , . , , . 1- 1- , .

28

,

2929

2930

Q10, 10 .

Q10 = Vt/Vt-10oC

2 < Q10 < 3, Q10~1.

2931

Transcriptionaltranslational feedback loop (TTFL) drives rhythms in gene expression At the beginning of the cycle, CLOCKBMAL1 protein complexes bind DNA at specific promoter regions (E-box) to activate the transcription of a family of genes including the period (Per1, Per2 and Per3) genes and cryptochrome (Cry1 and Cry2) genes. The levels of the transcripts for Per and Cry genes reach their peak during the period from midday to late in the day, whereas the PER and CRY proteins peak in the early night. The PERs, CRYs and other proteins form complexes that translocate back into the nucleus and turn off the transcriptional activity driven by CLOCKBMAL1 with a delay (owing to the time required for transcription, translation, dimerization and nuclear entry). Other feedback loops within the cells contribute to the precision and robustness of the core oscillation. 2932

2933