Rosculus
From Wikipedia, the free encyclopedia
| Rosculus | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Clade: | Sar |
| Clade: | Rhizaria |
| Phylum: | Cercozoa |
| Class: | Helkesea |
| Order: | Helkesida |
| Family: | Sainouridae |
| Genus: | Rosculus Hawes, 1963 |
| Species | |
| |
Rosculus is a genus of parasitic organisms which are poorly studied. Taxonomically, Rosculus is currently accepted to be in the family Sainouroidea, which contains a sister genus and Rosculus. Many species in this genus are aquatic, but genomic data shows that some species are terrestrial. Rosculus is thought to thrive in anaerobic and aerobic environments. This protist is very small in size, and it contains a massive genome. One defining characteristic of Rosculus is its discoidal cristae but morphologically.
Rosculus is a genus of organisms in the supergroup Rhizaria.[1] Under Rhizaria, we see a group of cercozoan flagellates, called Sainouroidea, which contains two genera of amoebae: Rosculus and its sister group, Guttulinopsis.[2][3] These two groups are distinguished because Guttulinopsis displays aggregate multicellularity, and they can have a fruiting body stage, and Rosculus does not.[3] Other than the fruiting structures and aggregate multicellularity, there is little to no morphological difference between these sister taxa.[3] 18S rDNA must be sequenced in many cases to differentiate species in the genus Rosculus vs. Guttulinopsis.[2] Using 18S V4 amplicons, researchers were able to place Rosculus as a Cercozoan flagellate to begin with.[2] Little research has been published on Sainouroideans, however, data suggests that this group is very genetically remarkably diverse.[3] Current publications suggest that Sainoiroidea contain five genera: Cholamonas, Sainouron, Helkesimastix, Guttulinopsis, and Rosculus.[3] Rosculus is not a well-studied genus in protistology. Like many protists, Rosculus has a limited quantity of published, up to date information. The taxonomic information published changes frequently and published scientific papers should be scouted recently for the most up to date information. Currently, Rosculus also contains a handful of published species.
Genomic information
Several published Rosculus species include R. ithacus, R. elongate, and R. terrestris.[2] One Rosculus species, R. vilicus is reported to have a massive mitochondrial genome, made up of about 185,000 bp.[1] For reference, human mitochondrial genomes only contain 16,569 bp.[4] Rosculus's nuclear genome contains 41 million bp.[1]
Size and locomotion
Rosculus is tiny in size. This genus contains organisms that range from 2-13 micrometers in length.[1] What is more interesting is the locomotion of Rosculus. When these species are on the move, they often range from 4.2 to 5.5 micrometers in diameter.[1] These organisms have an interesting movement style. Organisms in this group move very rapidly or abruptly. They use one long hyaline pseudopod to traverse their environments.[1] One paper suggests that the movement of Rosculus is rippling or wave-like.[3] When looking closely at Rosculus scientists have also observed a cyst formation as well, which is a sort of dormant reproductive stage where we do not see this movement.[1]
