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Sterol Composition and Biosynthetic Genes of the Recently Discovered Photosynthetic Alveolate, Chromera velia (Chromerida), a Close Relative of Apicomplexans
Author(s) -
Leblond Jeffrey D.,
Dodson Joshua,
Khadka Manoj,
Holder Sabrina,
Seipelt Rebecca L.
Publication year - 2012
Publication title -
journal of eukaryotic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 1066-5234
DOI - 10.1111/j.1550-7408.2012.00611.x
Subject(s) - sterol , biology , biosynthesis , squalene , biochemistry , algae , biogenesis , isomerase , gene , lanosterol , phytosterol , farnesyl diphosphate synthase , botany , cholesterol
Chromera velia is a recently discovered, photosynthetic, marine alveolate closely related to apicomplexan parasites, and more distantly to perkinsids and dinoflagellates. To date, there are no published studies on the sterols of C. velia . Because apicomplexans and perkinsids are not known to synthesize sterols de novo, but rather obtain them from their host organisms, our objective was to examine the composition of the sterols of C. velia to assess whether or not there is any commonality with dinoflagellates as the closest taxonomic group capable of synthesizing sterols de novo. Furthermore, knowledge of the sterols of C. velia may provide insight into the sterol biosynthetic capabilities of apicomplexans prior to loss of sterol biosynthesis. We have found that C. velia possesses two primary sterols, 24‐ethylcholesta‐5,22E‐dien‐3β‐ol, and 24‐ethylcholest‐5‐en‐3β‐ol, not common to dinoflagellates, but rather commonly found in other classes of algae and plants. In addition, we have identified computationally three genes, SMT 1 (sterol‐24C‐methyltransferase), FDFT 1 (farnesyl diphosphate farnesyl transferase, squalene synthase), and IDI 1 (isopentenyl diphosphate Δ‐isomerase), predicted to be involved in sterol biosynthesis by their similarity to analogous genes in other sterol‐producing eukaryotes, including a number of algae.