Abstract
Algae include a diverse array of photosynthetic eukaryotes excluding land plants. Explaining the origin of algal plastids continues to be a major challenge in evolutionary biology. Current knowledge suggests that plastid primary endosymbiosis, in which a single-celled protist engulfs and "enslaves" a cyanobacterium, likely occurred once and resulted in the primordial alga. This eukaryote then gave rise through vertical evolution to the red, green, and glaucophyte algae. However, some modern algal lineages have a more complicated evolutionary history involving a secondary endosymbiotic event, in which a protist engulfed an existing eukaryotic alga (rather than a cyanobacterium), which was then reduced to a secondary plastid. Secondary endosymbiosis explains the majority of algal biodiversity, yet the number and timing of these events is unresolved. Here we analyzed a five-gene plastid data set to show that a taxonomically diverse group of chlorophyll c2-containing protists comprising cryptophyte, haptophyte, and stramenopiles algae (Chromista) share a common plastid that most likely arose from a single, ancient (≈1,260 million years ago) secondary endosymbiosis involving a red alga. This finding is consistent with Chromista monophyly and implicates secondary endosymbiosis as an important force in generating eukaryotic biodiversity.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 15507-15512 |
| Number of pages | 6 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 99 |
| Issue number | 24 |
| DOIs | |
| State | Published - Nov 26 2002 |
| Externally published | Yes |
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Keywords
- Cryptophyte
- Haptophyte
- Plastid evolution
- Secondary endosymbiosis
- Stramenopiles
ASJC Scopus subject areas
- Genetics
- General
Cite this
The single, ancient origin of chromist plastids. / Yoon, Hwan Su; Hackett, Jeremiah; Pinto, Gabriele; Bhattacharya, Debashish.
In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 99, No. 24, 26.11.2002, p. 15507-15512.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The single, ancient origin of chromist plastids
AU - Yoon, Hwan Su
AU - Hackett, Jeremiah
AU - Pinto, Gabriele
AU - Bhattacharya, Debashish
PY - 2002/11/26
Y1 - 2002/11/26
N2 - Algae include a diverse array of photosynthetic eukaryotes excluding land plants. Explaining the origin of algal plastids continues to be a major challenge in evolutionary biology. Current knowledge suggests that plastid primary endosymbiosis, in which a single-celled protist engulfs and "enslaves" a cyanobacterium, likely occurred once and resulted in the primordial alga. This eukaryote then gave rise through vertical evolution to the red, green, and glaucophyte algae. However, some modern algal lineages have a more complicated evolutionary history involving a secondary endosymbiotic event, in which a protist engulfed an existing eukaryotic alga (rather than a cyanobacterium), which was then reduced to a secondary plastid. Secondary endosymbiosis explains the majority of algal biodiversity, yet the number and timing of these events is unresolved. Here we analyzed a five-gene plastid data set to show that a taxonomically diverse group of chlorophyll c2-containing protists comprising cryptophyte, haptophyte, and stramenopiles algae (Chromista) share a common plastid that most likely arose from a single, ancient (≈1,260 million years ago) secondary endosymbiosis involving a red alga. This finding is consistent with Chromista monophyly and implicates secondary endosymbiosis as an important force in generating eukaryotic biodiversity.
AB - Algae include a diverse array of photosynthetic eukaryotes excluding land plants. Explaining the origin of algal plastids continues to be a major challenge in evolutionary biology. Current knowledge suggests that plastid primary endosymbiosis, in which a single-celled protist engulfs and "enslaves" a cyanobacterium, likely occurred once and resulted in the primordial alga. This eukaryote then gave rise through vertical evolution to the red, green, and glaucophyte algae. However, some modern algal lineages have a more complicated evolutionary history involving a secondary endosymbiotic event, in which a protist engulfed an existing eukaryotic alga (rather than a cyanobacterium), which was then reduced to a secondary plastid. Secondary endosymbiosis explains the majority of algal biodiversity, yet the number and timing of these events is unresolved. Here we analyzed a five-gene plastid data set to show that a taxonomically diverse group of chlorophyll c2-containing protists comprising cryptophyte, haptophyte, and stramenopiles algae (Chromista) share a common plastid that most likely arose from a single, ancient (≈1,260 million years ago) secondary endosymbiosis involving a red alga. This finding is consistent with Chromista monophyly and implicates secondary endosymbiosis as an important force in generating eukaryotic biodiversity.
KW - Cryptophyte
KW - Haptophyte
KW - Plastid evolution
KW - Secondary endosymbiosis
KW - Stramenopiles
UR - http://www.scopus.com/inward/record.url?scp=0037180558&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037180558&partnerID=8YFLogxK
U2 - 10.1073/pnas.242379899
DO - 10.1073/pnas.242379899
M3 - Article
C2 - 12438651
AN - SCOPUS:0037180558
VL - 99
SP - 15507
EP - 15512
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 24
ER -