Monocercomonoides

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Monocercomonoides
Monocercomonoides melolanthae
Scientific classification
Domain:	Eukaryota
(unranked):	Excavata
Phylum:	Metamonada
Class:	Preaxostyla
Order:	Oxymonadida
Family:	Polymastigidae
Genus:	Monocercomonoides Travis, 1932
Species
M. adarshii Mali, Kulkarni & Mali, 2001[1] M. aurangabade Mali & Patil, 2003[2] M. bovis Jensen & Hammond, 1964[3] M. cetoniae Travis, 1932 M. dobelli Krishnamurthy & Madre, 1979[4] M. garnhami Rao, 1969[5] M. ganapatii Rao, 1969[5] M. gryllusae Sultana & Krishnamurthy, 1978[6] M. hausmanni Radek, 1997[7][8] M. khultabadae Mali & Mali, 2004[9] M. marathwadensis Krishnamurthy & Sultana 1976[10] M. mehdii Krishnamurthy, 1967[11] M. omergae Mali, Kulkarni & Mali, 2001[1] M. polyphagae Krishnamurthy & Sultana 1976[10] M. qadrii Rao, 1969[5] M. sayeedi Abraham, 1961[12] M. singhi Krishnamurthy, 1967[11] M. termitis Krishnamurthy & Sultana 1979[13]

Monocercomonoides is a genus of flagellate Excavata belonging to the order Oxymonadida. It was established by Bernard V. Travis and was first described as those with "polymastiginid flagellates having three anterior flagella and a trailing one originating at a single basal granule located in front of the anteriorly positioned nucleus, and a more or less well-defined axostyle".^[14] It is the first eukaryotic genus to be found to completely lack mitochondria, and all hallmark proteins responsible for mitochondrial function. The genus also lacks any other mitochondria related organelles (MROs) such as hydrogenosomes or mitosomes.^[15] Data suggests that the absence of mitochondria is not an ancestral feature, but rather due to secondary loss. Monocercomonoides sp. was found to obtain energy through an enzymatic action of nutrients absorbed from the environment.^[15] The genus has replaced the iron-sulfur cluster assembly pathway with a cytosolic sulfur mobilization system, likely acquired by horizontal gene transfer from a eubacterium of a common ancestor of oxymonads.^[16] These organisms are significant because they undermine assumptions that eukaryotes must have mitochondria to properly function. The genome of Monocercomonoides exilis has approximately 82 million base pairs (82 Mbp), with 18 152 predicted protein-coding genes.^[17]