Table 4 Antisense RNAs transcribed within the ORF or 5' UTR of genes involved in heterocyst differentiation
Gene | Gene Function | Gene Expression After Nitrogen Step-down | RNA Location | Antisense RNA Expression After Nitrogen Step-down |
|---|---|---|---|---|
narB (alr0612) | nitrate reductase | increased by 12 h | narB ORF and 5' UTR | no change |
fraH (alr1603) | cell-cell connection | increased by 12 h | alr1603 ORF | slight decrease by 21 h |
alr3649 | heterocyst specific ABC transporter | increased by 12 h | 5' end of alr3649 ORF into upstream gene | increased by 12 h |
alr3479 | similar to nitrogen regulation protein NtrR | decreased slightly at 6 h only | alr3479 ORF | increased by 21 h |
glnB (all2319) | nitrogen assimilation | no change | glnB 5' UTR | no change |
hetR (alr2339) | heterocyst differentiation regulator | increased by 6 h | hetR ORF and 5' UTR | decreased by 21 h |
hetC (alr2817) | heterocyst differentiation | increased by 12 h | two RNAs, one in hetC ORF and one in hetC-hetP intergenic region | increased by 12 h |
hetF (alr3546) | heterocyst differentiation | no change | hetF ORF and 5' UTR; NsiR1* | increased by 6 h |
all3558 | nitrogen assimilation regulation | no change | all3558 ORF | increased by 21 h |
hepK (all4496) | exopolysaccharide synthesis | increased by 12 h | hepK ORF; contains repeat sequence at 5' end | no change |
nblA | phycobilisome degradation | increased by 12 h; largest increase at 21 h | nblA ORF and 5' and 3' UTRs | antisense transcription until 12 h only |
hglE (alr5351) | heterocyst-specific glycolipid | increased by 12 h; largest increase at 21 h | hglE 3' end of ORF | increased by 12 h |
hglD (alr5354) | heterocyst-specific glycolipid | increased by 21 h | hglD ORF and 5' UTR | no change |
hglC (alr5355) | heterocyst specific glycolipid gene | increased by 6 h; largest increase at 21 h | hglC ORF | increased at 6 h only |