Scientists have recently discovered the first example of a plant living symbiotically within a vertebrate, broadening our understanding of what sorts of symbioses are possible.
The spotted salamander Ambystoma maculatum is known to engage in a symbiotic relationship with the algae Oophila amblystomatis during embryonic development. Developing salamander eggs are covered in an algae-filled slime. The embryos produce nitrogen-rich waste, which the algae use for nutrition. In turn, the algae increase the amount of oxygen available to A. maculatum through photosynthesis.
This mutualistic relationship has long been understood. Recently, transmission electron microscopy, a high resolution microscopic imaging technology, has revealed O. amblystomatis cells residing within salamander embryos. Time-lapse videos of embryonic development reveal a fluorescent green flash occurring within an embryo as its nervous system forms.
There is evidence that these symbiotic algae may be maternally derived- they are the same algae that occur in female oviducts, where the embryo-encompassing jelly sacs form.
This unique symbiosis may provide insight into the early formation of eukaryotic cells. Chloroplasts, the principle photosynthetic organelle in plant cells, are thought to be the product of an ancient symbiosis between a free-living photosynthetic prokaryote and a larger proto-cell.
Credit: Petherick, A. A solar salamander. Nature News. Nature. 30 July 2010.