Editing Stramenopile (section)

== Characteristics ==

{{multiple image
|image1=Cafeteria roenbergensis FENCHEL and D J PATTERSON schematic drawing.svg
|caption1=Schematic drawing of ''[[Cafeteria roenbergensis]]'' (a heterotrophic [[bicosoecid]]), a common bacterivore in marine ecosystems: the anterior flagellum is tripartite and covered with hairs ([[mastigoneme]]s); the posterior flagellum is without hairs.
|image2=Cafeteria roenbergensis atcc50561 Protsville.jpg
|caption2=Two living ''C. roenbergensis''. Light micrograph. The cells are about 6 µm long. The anterior flagellum beats with an undulating pattern, the posterior (recurrent or smooth) flagellum usually holds the cell to the substrate.
}}

The presumed [[apomorphy]] of tripartite flagellar hairs in stramenopiles is well characterized. The basal part of the hair is flexible and inserts into the cell membrane; the second part is dominated by a long stiff tube (the 'straw' or 'stramen'); and finally the tube is tipped by many delicate hairs called [[mastigoneme]]s.<ref name="Bouck 1971">{{cite journal |last=Bouck |first=G. Benjamin |title=The structure, origin, and composition of the tubular mastigonemes of the ''Ochromonas'' flagellum |journal=Journal of Cell Biology |volume=50 |issue=2 |date=1 August 1971 |doi=10.1083/jcb.50.2.362 |pages=362–384|pmid=5123323 |pmc=2108286 }}</ref> The proteins that code for the mastigonemes appear to be exclusive to the stramenopile clade, and are present even in taxa (such as diatoms) that no longer have such hairs.<ref name="Blackman Arikawa Yamada Suzaki 2011">{{cite journal |last1=Blackman |first1=Leila M. |last2=Arikawa |first2=Mikihiko |last3=Yamada |first3=Shuhei |last4=Suzaki |first4=Toshinobu |last5=Hardham |first5=Adrienne R. |title=Identification of a Mastigoneme Protein from Phytophthora nicotianae |journal=Protist |volume=162 |issue=1 |year=2011 |doi=10.1016/j.protis.2010.01.005 |pages=100–114|pmid=20663714 }}</ref>

Most stramenopiles have two flagella near the apex.<ref name="Yoon Andersen Boo Bhattacharya 2009 pp. 721–731">{{cite book |last1=Yoon |first1=H.S. |last2=Andersen |first2=R.A. |last3=Boo |first3=S.M. |last4=Bhattacharya |first4=D. |title=Encyclopedia of Microbiology |chapter=Stramenopiles |publisher=Elsevier |year=2009 |doi=10.1016/b978-012373944-5.00253-4 |pages=721–731|isbn=9780123739445 }}</ref> They are usually supported by four [[microtubule]] roots in a distinctive pattern. There is a transitional helix inside the flagellum where the beating [[axoneme]] with its distinctive geometric pattern of nine peripheral couplets around two central microtubules changes into the nine-triplet structure of the basal body.<ref name="Fu Nagasato Oka Cock 2014 pp. 662–675">{{cite journal |last1=Fu |first1=Gang |last2=Nagasato |first2=Chikako |last3=Oka |first3=Seiko |last4=Cock |first4=J. Mark |last5=Motomura |first5=Taizo |title=Proteomics Analysis of Heterogeneous Flagella in Brown Algae (Stramenopiles) |journal=Protist |volume=165 |issue=5 |year=2014 |doi=10.1016/j.protis.2014.07.007 |pages=662–675|pmid=25150613 |s2cid=7936118 |url=https://hal.sorbonne-universite.fr/hal-01113862/file/PROTIST.pdf }}</ref>

=== Plastids ===

Many stramenopiles have [[plastid]]s which enable them to [[photosynthesis]]e, using light to [[autotroph|make their own food]]. Those plastids are coloured off-green, orange, golden or brown because of the presence of [[chlorophyll a]], [[chlorophyll c]], and [[fucoxanthin]]. This form of plastid is called a stramenochrome or [[chromoplast]].{{efn|They are not called chloroplasts, the most common form of photosynthetic plastid. If used narrowly, a chloroplast is a plastid which contains chlorophyll B, as in [[green algae]], some [[euglenid]]s, and the [[land plants]].}}  The most significant autotrophic stramenopiles are the [[brown algae]] (wracks and many other seaweeds), and the [[diatom]]s. The latter are among the most significant primary producers in marine and freshwater ecosystems.<ref name="Leipe Wainright Gunderson Porter 1994">{{cite journal |last1=Leipe |first1=D. D. |last2=Wainright |first2=P. O. |last3=Gunderson |first3=J. H. |last4=Porter |first4=D. |last5=Patterson |first5=D. J. |last6=Valois |first6=F. |last7=Himmerich |first7=S. |last8=Sogin |first8=M. L. |display-authors=3 |title=The stramenopiles from a molecular perspective: 16S-like rRNA sequences from Labyrinthuloides minuta and Cafeteria roenbergensis |journal=Phycologia |volume=33 |issue=5 |year=1994 |doi=10.2216/i0031-8884-33-5-369.1 |pages=369–377}}</ref> Most molecular analyses suggest that the most basal stramenopiles lacked plastids and were accordingly colourless [[heterotroph]]s, feeding on other organisms. This implies that the stramenopiles arose as heterotrophs, diversified, and then some of them acquired chromoplasts. Some lineages (such as the [[axodine]] lineage that included the chromophytic [[pedinellid]]s, colourless ciliophryids, and colourless actinophryid heliozoa) have secondarily reverted to heterotrophy.<ref name="Leyland Leu Boussiba 2017">{{cite journal |last1=Leyland |first1=Ben |last2=Leu |first2=Stefan |last3=Boussiba |first3=Sammy |title=Are Thraustochytrids algae? |journal=Fungal Biology |volume=121 |issue=10 |year=2017 |doi=10.1016/j.funbio.2017.07.006 |pages=835–840|pmid=28889907 }}</ref><ref name="Derelle López-García Timpano Moreira 2016">{{cite journal |last1=Derelle |first1=Romain |last2=López-García |first2=Purificación |last3=Timpano |first3=Hélène |last4=Moreira |first4=David |title=A Phylogenomic Framework to Study the Diversity and Evolution of Stramenopiles (=Heterokonts) |journal=Molecular Biology and Evolution |volume=33 |issue=11 |date=10 August 2016 |doi=10.1093/molbev/msw168 |pages=2890–2898|pmid=27512113 |pmc=5482393 }}</ref>