Cryptomonad; The Eukaryote With 4 or More Genome

3 months ago

If you ever Google search about an Algae with four genomes and you see the word Cryptomonads, it could be shocking to you because you first start to ask yourself how possible it is that they have that number of genomes seeing that it is a lot but what does it really mean for cyptomonads to have four genome. Wait! before I continue do not relate the crypto suffix to cryptocurrency, because they are not the same and these algae has nothing to do with cryptocurrency.

In 1831, the genus cryptomonads was introduced by Christian Gottfried Ehrenberg who was a microbiologist. Cryptomonads are majorly greenish brown in color and it would be expected that since they are green, they should have chlorophyl and accessory pigment in their photosynthetic organelles known as plastid and so they should be able to photosynthesize. And while majority of Cryptomonads are photosynthetic, a lot of them are not utilize photosynthesis like some colorless species like the Cryptomonads paramecium.

^{wikimedia: CSIRO}

Seeing that the Cryptomonads paramecium doesn't utilize photosynthesis, you might think it doesn't need a photosynthetic organelle which is a plastid but it actually does so how did this come into being?

One of the ancestors of cryptomonads consumed a red algae and kept a part of the algae which was the plastid around and the plastid itself was a product of endosymbiosis (which is the process where an eukaryotic cell engulfs a prokaryote, leading to the creation of organelles) which meant that the red algae plastid were a function of primary endosymbiosis while the cryptomonads was a product of secondary endosymbiosis. Cryptomonads didn't only take the plastid, it also took over the Phycoerythrin which is the purple pigment of the red algae so as to be able to utilize photosynthesis.

Its no doubt that cryptomonads is good at endosymbiosis but plastid and phycoerthrin weren't the only organelles that were taken over, they also got the mitochondrion which was what brought about it having four genomes. Its first genome is the Nuclear DNA which is its foundational identity, then it has the Plastid DNA from the red algae, the mitochondrial DNA, and the Nucleomorph.

^{flickr: Proyecto}

With this four genomes, cryptomonads are different from other eukaryotes that have developed organelles by consuming other prokaryotes (endosymbiosis) because other eukaryotes have lost the remains of the endosymbiont. We can all agree that cryptomonads are good at keeping organelles they get from endosymbiosis and that is why cyptomonads paramecium still has plastid when it is not using it for photosynthesis.

When scientists decided to understand why the eukaryote will keep the organelle when it wasn't useful to them, they realized that the organelle is actually useful but for making fatty acids, amino acids and for doing a whole lot of other things. Cryptomonads seem to be very good at housing other organisms or organelles from them as scientist while researching a culture of cyptomonads strain, found two bacterial endosymbionts and a bacteriophage living in the cryptomonads and scientist said the strain of cryptomonads has 7 genomes.

It is no doubt that cryptomonads are able to ingest eukaryotes and in the process keep a part of them to form an organelle which then increases their genome.