f*******g
发帖数: 79 | 1 有RNA到DNA的逆转录过程， 有些细胞中DNA发生变法，有一些保持不变。 难道一个人
体内各个细胞的DNA还是有细微差别的？ | a***e
发帖数: 1010 | | n********k
发帖数: 2818 | 3 B cells and LINE elements, transposons etc etc...tons of variations...DNA
damage repair...
【在 f*******g 的大作中提到】
: 有RNA到DNA的逆转录过程， 有些细胞中DNA发生变法，有一些保持不变。 难道一个人
: 体内各个细胞的DNA还是有细微差别的？
| m*****u
发帖数: 15526 | 4 这个显然不成立。起码淋巴细胞和生殖细胞DNA和普通体细胞是不同的
【在 f*******g 的大作中提到】
: 有RNA到DNA的逆转录过程， 有些细胞中DNA发生变法，有一些保持不变。 难道一个人
: 体内各个细胞的DNA还是有细微差别的？
| m*********e
发帖数: 565 | 5 if consider epigenetics, there are tons of deference between cells to cells. | l**********1
发帖数: 5204 | 6 Bingo
人的血红细胞的生物钟韵律调控都可以不用DNA 的 transcription-translation feedback loops
各个血红细胞应该不会只有一套proteomics 不然生物钟韵律调控如何实现?
Nature. 2011 Jan 27;469(7331):498-
Circadian clocks in human red blood cells.
//www.ncbi.nlm.nih.gov/pubmed/21270888
full text link:
//www.dormivigilia.com/wp-content/uploads/2011/02/nature09702.pdf
Abstract
Circadian (～24 hour) clocks are fundamentally important for coordinated physiology in organisms as
diverse
as cyanobacteria and humans. All current models of the molecular circadian clockwork in eukaryotic cells
are based on transcription-translation feedback loops. Non-transcriptional mechanisms in the clockwork
have been difficult to study in mammalian systems. We circumvented these problems by developing novel
assays using human red blood cells, which have no nucleus (or DNA) and therefore cannot perform
transcription. Our results show that transcription is not required for circadian oscillations in humans, and
that non-transcriptional events seem to be sufficient to sustain cellular circadian rhythms. Using red blood
cells, we found that peroxiredoxins, highly conserved antioxidant proteins, undergo ～24-hour redox
cycles,
which persist for many days under constant conditions (that is, in the absence of external cues). Moreover,
these rhythms are entrainable (that is, tunable by environmental stimuli) and temperature-compensated,
both key features of circadian rhythms. We anticipate that our findings will facilitate more sophisticated
cellular clock models, highlighting the interdependency of transcriptional and non-transcriptional
oscillations in potentially all eukaryotic cells.
【在 a***e 的大作中提到】
: Red Blood Cell
| l**********1
发帖数: 5204 | 7 That might lead to Chaos (some times)
please refer:
//www.biomedcentral.com/1752-0509/5/85
cells.
【在 m*********e 的大作中提到】
: if consider epigenetics, there are tons of deference between cells to cells.
| s****l
发帖数: 10462 | | o********r
发帖数: 775 | |
|
