Algae grows inside salamander cells

In a recent research study co-authored by IU biologist Roger Hangarter and Dalhousie University biologist Ryan Kerney, green algae were found inside the cells of spotted salamander embryos.

While the algae have long been known to inhabit the inside of spotted salamander eggs, this is the first time they have been found inside the animal’s cells.

“This suggests that other animals, local like the salamanders and exotic, could have this type of symbiosis. This is also suggested by the fact that many amphibians have algae inside of their eggs,” Hangarter said.

More importantly, this is the first time algae have been found in the cells of a vertebrate, an animal with a backbone. Algae have been found multiple times in invertebrates, but never in vertebrates.

Kerney, who found out about Hangarter’s research through IU biologist Rudy Raf, had been independently studying the salamanders and learned that Hangarter had time-lapse videos of salamander embryos during development.

“The videos showed that at a certain stage of development in the cell, the algae have a sudden bloom,” Kerney said.

The algae could be cued by a nitrogenous base in the embryos, which the algae would thrive on. Nonetheless, the embryos don’t grow as well if the algae are not as prevalent, Kerney said.

The researchers were able to see the algae using fluorescent microscopy. When a certain wavelength is shone on the algae, they fluoresce to a bright red, easily distinguishing themselves from the natural components of the cell. The biologists also used a string of nucleic acids that binds to the algae and were able to track the string-algae combination inside the cell.

The researchers were not able to find any algae in adult salamanders, but Hangarter said he suspects that if the adults do have algae in their cells, it is transferred through them into their eggs. Kerney is of the same opinion, saying the algae could be inherited as an algal gene.

“Some scientists are trying to insert algae in the cells of vertebrates, and it is really interesting that we found it in the wild, right in ponds,” Kerney said.

Kerney said unfortunately, the salamanders’ pond habitat, though ranging from east Texas all the way to Nova Scotia, is being destroyed at a fast rate.

“One of the first things people do when they get land is fill up ponds because they don’t want wet spots around,” Hangarter said. The salamanders, though incredibly useful in embryological studies, are in less and less supply.

The researchers said they hope they can raise awareness for this useful animal through their findings.

“The salamanders are an interesting part of biology that most people aren’t aware of or have even seen,” Hangarter said. “Hopefully the study brings a little more awareness to them.”