Nitrogen Availability Gene Expression Project
Global Gene Expression of Prochlorococcus Ecotypes In Response To Changes In Nitrogen Availability
Mol Syst Biol. 2006;2:53. Epub 2006 Oct 3.

Nitrogen (N) often limits biological productivity in the oceanic gyres where Prochlorococcus is the most abundant photosynthetic organism. The Prochlorococcus community is composed of strains, such as MED4 and MIT9313, that have different N utilization capabilities and that belong to ecotypes with different depth distributions. An interstrain comparison of how Prochlorococcus responds to changes in ambient nitrogen is thus central to understanding its ecology. We quantified changes in MED4 and MIT9313 global mRNA expression, chlorophyll fluorescence, and photosystem II photochemical efficiency (Fv/Fm) along a time series of increasing N starvation. In addition, the global expression of both strains growing in ammonium-replete medium was compared to expression during growth on alternative N sources. There were interstrain similarities in N regulation such as the activation of a putative NtcA regulon during N stress. There were also important differences between the strains such as in the expression patterns of carbon metabolism genes, suggesting that the two strains integrate N and C metabolism in fundamentally different ways.

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Pubmed: 17016519

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Browse N-replete: 0 h N deprivation: 0 h MED4 and MIT9313
Browse N-replete: 3 h N deprivation: 3 h MED4 and MIT9313
Browse N-replete: 6 h N deprivation: 6 h MED4 and MIT9313
Browse N-replete: 12 h N deprivation: 12 h MED4 and MIT9313
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Browse N-replete: 48 h N deprivation: 48 h MED4 and MIT9313
Browse N-replete: log phase Urea: log phase MED4 and MIT9313
Browse N-replete: log phase Nitrite: log phase MIT9313 only
Browse N-replete: log phase Cyanate: log phase MED4 only