# Analysis of fate determination of vegetative cells with reduced phycocyanin content in a multicellular cyanobacterium using Raman microscopy

## TL;DR

The paper uses Raman microscopy to study how certain cells in a cyanobacterium change under nitrogen deprivation, revealing that some cells can switch between states.

## Contribution

The study introduces 'proheterocysts' as a new intermediate cell state that can revert or divide instead of differentiating.

## Key findings

- Proheterocysts have lower phycocyanin-related Raman band intensity than vegetative cells.
- Proheterocysts can divide or revert to vegetative cells instead of differentiating into heterocysts.
- Raman microscopy effectively tracks cell fate determination in cyanobacteria.

## Abstract

The one-dimensional multicellular cyanobacterium
Anabaena
sp. PCC 7120 exhibits two different cell types under nitrogen-deprived conditions. We found that the intensity of the Raman band at 1,629 cm
−1
, which is associated with phycocyanin, was higher in undifferentiated cells (vegetative cells) than in differentiated cells (heterocysts). We observed cells whose band intensity at 1,629 cm
−1
was statistically lower than that of vegetative cells, and named them “proheterocysts”. We found that proheterocysts did not necessarily differentiate, and could divide or revert to being vegetative cells, as defined by having a higher band intensity at 1,629 cm
−1
.