Spermidine is bound to a unique protein in early sea urchin embryos.

@article{Canellakis1985SpermidineIB,
  title={Spermidine is bound to a unique protein in early sea urchin embryos.},
  author={Zoe Nakos Canellakis and Philip K. Bondy and Anthony A. Infante},
  journal={Proceedings of the National Academy of Sciences of the United States of America},
  year={1985},
  volume={82 22},
  pages={7613-5}
}
Spermidine is rapidly taken up and becomes bound to protein during the very early hours of sea urchin embryogenesis. During the first 6 hr after fertilization of freshly obtained sea urchin eggs (Strongylocentrotus purpuratus), which are incubated in the presence of exogenous [3H]-spermidine, up to 7% of the total cell-associated spermidine appears uniquely… CONTINUE READING