alexa The number of symbiotic origins of organelles.
General Science

General Science

Biological Systems: Open Access

Author(s): CavalierSmith T

Abstract Share this page

Abstract Mitochondria and chloroplasts both originated from bacterial endosymbionts. The available evidence strongly supports a single origin for mitochondria and only somewhat less strongly a single, slightly later, origin for chloroplasts. The arguments and evidence that have sometimes been presented in favor of the alternative theories of the multiple or polyphyletic origins of these two organelles are evaluated and the kinds of data that are needed to test more rigorously the monophyletic theory are discussed. Although chloroplasts probably originated only once, eukaryotic algae are polyphyletic because chloroplasts have been secondarily transferred to new lineages by the permanent incorporation of a photosynthetic eukaryotic algal cell into a phagotrophic protozoan host. How often this has happened is much less clear. It is particularly unclear whether or not the chloroplasts of typical dinoflagellates and euglenoids originated in this way from a eukaryotic symbiont: their direct divergence from the ancestral chloroplast cannot be ruled out and indeed has several arguments in its favor. The evidence for and against the view that the chloroplast of the kingdom Chromista was acquired in a single endosymbiotic event is discussed. The possibility that even the chloroplast of Chlorarachnion might have been acquired during the same symbiosis that created the cryptomonad cell, if the symbiont was a primitive alga that had chlorophyll a, b and c as well as phycobilins, is also considered. An alga with such a combination of pigments might have been ancestral to all eukaryote algae.
This article was published in Biosystems and referenced in Biological Systems: Open Access

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Relevant Topics

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

Agri & Aquaculture Journals

Dr. Krish

1-702-714-7001Extn: 9040

Biochemistry Journals

Datta A

1-702-714-7001Extn: 9037

Business & Management Journals


1-702-714-7001Extn: 9042

Chemistry Journals

Gabriel Shaw

1-702-714-7001Extn: 9040

Clinical Journals

Datta A

1-702-714-7001Extn: 9037

Engineering Journals

James Franklin

1-702-714-7001Extn: 9042

Food & Nutrition Journals

Katie Wilson

1-702-714-7001Extn: 9042

General Science

Andrea Jason

1-702-714-7001Extn: 9043

Genetics & Molecular Biology Journals

Anna Melissa

1-702-714-7001Extn: 9006

Immunology & Microbiology Journals

David Gorantl

1-702-714-7001Extn: 9014

Materials Science Journals

Rachle Green

1-702-714-7001Extn: 9039

Nursing & Health Care Journals

Stephanie Skinner

1-702-714-7001Extn: 9039

Medical Journals

Nimmi Anna

1-702-714-7001Extn: 9038

Neuroscience & Psychology Journals

Nathan T

1-702-714-7001Extn: 9041

Pharmaceutical Sciences Journals

Ann Jose

1-702-714-7001Extn: 9007

Social & Political Science Journals

Steve Harry

1-702-714-7001Extn: 9042

© 2008- 2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version