Identification of regulatory sites in genomic DNA
Costly nitrogen fixation? Pay only when necessary
How to avoid being fooled by imposters?
How do cells control gene expression? Let's whittle down the question.
Heterocysts are expensive to make and maintain, however,
and you are interested studying the mechanism by which Nostoc regulates
the appearance of heterocysts. When an alternative source of nitrogen (like ammonia) is
present, Nostoc makes no heterocysts. When that source is consumed or removed,
vegetative cells differentiate into heterocysts within about 18 hours.
do the cells sense nitrogen deprivation and translate that perception into
the induction of the genes necessary for heterocyst differentiation? At present,
the answer to this question is not known.
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