tissue-specific promoters

[simpleton]

why exactly makes the promoters tissue specific? it's inducibility? but then what control the expression of the inducers/repressors in specific tissues? other regulated expression of inducers and repressors again?

all in all, the stream of regulation; how does it control the types of active promoters in specific tissues?

eh, does all cells in our body have the same kind of heterochomatin/euchromatin structures or different tissues have got different chromatin organisation?

one more question, how many origin of transfer is there in a F+ plasmid? is it one?

many thanks in advance!

[JackBean]

from back - I think, that different tissues have different structures of chromatin

there are plenty of transcription factors regulating each other and the expression pattern is determined by differential expression of these TFs. In Alberts' Cell there is a picture, where is shown, how you can easily with like 5 TFs obtain maybe 16 different cell types

[simpleton]

wow! can you recall which chapt is the picture from? otherwise it's okay. many thanks again for helping me out!

[kolean]

Yes, not only is it the transcription factors that are being expressed, but the accessibility of the DNA by remodeling the chromatin to either slide the nucleosomes over, or modify the histones (of the nucleosome) in such a way as to provide access to the gene's promoter regions.

[JackBean]

in the 4th grey addition it's on page 425 picture 7-73
(I recommend to read whole chapter, there are more examples from the real life;)

[simpleton]

yeah sure! will do it. haha i got the 6th edition. but it should be around that page-range. many thanks!

[JackBean]

there's a pyramide of cells with numbers in it signing the TFs

[simpleton]

got it. thanks jackbean and kolean.