Salpingoeca rosetta

{{Taxobox

| image = Protero-4.png

| image_caption =

| domain = Eukaryota

| unranked_superregnum = Opisthokonta

| unranked_regnum = Holozoa

| classis = Choanoflagellatea

| ordo = Choanoflagellida

| familia = Salpingoecidae

| genus = Salpingoeca

| species = S. rosetta

| binomial = Salpingoeca rosetta

| binomial_authority = Dayel et al., 2011{{cite journal | vauthors = Dayel MJ, Alegado RA, Fairclough SR, Levin TC, Nichols SA, McDonald K, King N | title = Cell differentiation and morphogenesis in the colony-forming choanoflagellate Salpingoeca rosetta | journal = Developmental Biology | volume = 357 | issue = 1 | pages = 73–82 | date = September 2011 | pmid = 21699890 | pmc = 3156392 | doi = 10.1016/j.ydbio.2011.06.003 }}

| subdivision_ranks = Subspecies or strains

| subdivision =

Salpingoeca rosetta ATCC 50818
Salpingoeca rosetta ATCC50818

| synonyms =

Proterospongia sp. ATCC 50818
Salpingoeca sp. ATCC 50818
Salpingoeca sp. ATCC50818

}}

Salpingoeca rosetta is a species of Choanoflagellates in the family Salpingoecidae. It is a rare marine eukaryote consisting of a number of cells embedded in a jelly-like matrix. This organism demonstrates a very primitive level of cell differentiation and specialization. This is seen with flagellated cells and their collar structures that move the cell colony through the water.

Similar low level cellular differentiation and specification can also be seen in sponges. They also have collar cells (also called choanocytes due to their similarities to choanoflagellates) and amoeboid cells arranged in a gelatinous matrix.
Unlike S. rosetta, sponges also have other cell-types that can perform different functions. Also, the collar cells of sponges beat within canals in the sponge body, whereas Salpingoeca rosetta's collar cells reside on the inside and it lacks internal canals. Despite these minor differences, there is strong evidence that Proterospongia and Metazoa are highly related.{{citation needed|date=October 2023}}

Its genome has been studied as a model for pre-metazoan evolution.{{cite journal | vauthors = Fairclough SR, Chen Z, Kramer E, Zeng Q, Young S, Robertson HM, Begovic E, Richter DJ, Russ C, Westbrook MJ, Manning G, Lang BF, Haas B, Nusbaum C, King N | title = Premetazoan genome evolution and the regulation of cell differentiation in the choanoflagellate Salpingoeca rosetta | journal = Genome Biology | volume = 14 | issue = 2 | pages = R15 | date = February 2013 | pmid = 23419129 | pmc = 4054682 | doi = 10.1186/gb-2013-14-2-r15 | doi-access = free }} The genome is 55 megabases in size. Homologs of cell adhesion, neuropeptide and glycosphingolipid metabolism genes are present in the genome.

File:Dayel Protero Colonies inset.jpg

Reproduction cycle

S. rosetta has a sexual cycle during which it transitions between haploid and diploid stages.{{cite journal | vauthors = Levin TC, King N | title = Evidence for sex and recombination in the choanoflagellate Salpingoeca rosetta | journal = Current Biology | volume = 23 | issue = 21 | pages = 2176–80 | date = November 2013 | pmid = 24139741 | pmc = 3909816 | doi = 10.1016/j.cub.2013.08.061 }} When nutrients become limiting, haploid cultures of S. rosetta become diploid. This ploidy shift coincides with mating during which small, flagellated cells fuse with larger flagellated cells. Evidence has also been obtained for historical mating and recombination in S. rosetta.

S. rosetta can be induced to undergo sexual reproduction by the marine bacterium Vibrio fischeri.{{cite journal | vauthors = Woznica A, Gerdt JP, Hulett RE, Clardy J, King N | title = Mating in the Closest Living Relatives of Animals Is Induced by a Bacterial Chondroitinase | journal = Cell | volume = 170 | issue = 6 | pages = 1175–1183.e11 | date = September 2017 | pmid = 28867285 | doi = 10.1016/j.cell.2017.08.005 | pmc = 5599222 }} A single protein of V. fischeri, EroS, fully recapitulates the aphrodesiac-like activity of living V. fischeri.

Colonial organization

S. rosetta was named for the rosette-shaped colonies formed by its cells.{{cite journal | vauthors = Fairclough SR, Dayel MJ, King N | title = Multicellular development in a choanoflagellate | journal = Current Biology | volume = 20 | issue = 20 | pages = R875-6 | date = October 2010 | pmid = 20971426 | pmc = 2978077 | doi = 10.1016/j.cub.2010.09.014 }} The colonies are held together by adhesion molecules long thought to be found only in Metazoan organisms.{{cite journal | vauthors = King N, Hittinger CT, Carroll SB | title = Evolution of key cell signaling and adhesion protein families predates animal origins | journal = Science | volume = 301 | issue = 5631 | pages = 361–3 | date = July 2003 | pmid = 12869759 | doi = 10.1126/science.1083853 | bibcode = 2003Sci...301..361K | s2cid = 9708224 }} Additionally, recent evidence suggests that a bacterial sulfonolipid, called rosette inducing factor (RIF-1) and produced by Algoriphagus machipongonensis, triggers colony formation in S. rosetta.{{cite journal | vauthors = Alegado RA, Brown LW, Cao S, Dermenjian RK, Zuzow R, Fairclough SR, Clardy J, King N | title = A bacterial sulfonolipid triggers multicellular development in the closest living relatives of animals | journal = eLife | volume = 1 | pages = e00013 | date = October 2012 | pmid = 23066504 | doi = 10.7554/eLife.00013 | pmc = 3463246 | doi-access = free }} The effect of RIF-1 on colony formation in S. rosetta has been suggested as an example of how interactions between bacteria and eukaryotes may have led to multicellularity in the latter.

References

External links

Category:Choanoflagellate species

Category:Protists described in 2011