Featured Research

from universities, journals, and other organizations

Why red algae never colonized dry land

Date:
March 20, 2013
Source:
CNRS (Délégation Paris Michel-Ange)
Summary:
The first red alga genome has just been sequenced. The genome of Chondrus crispus, also known by the Breton name 'pioka', turns out to be small and compact for a multicellular organism. It has fewer genes than several other species of unicellular algae, which raises a number of questions about the evolution of red algae. This low number of genes could explain why these organisms never colonized dry land, unlike their green counterparts-from which all terrestrial plants are descended.

A Chondrus crispus red alga.
Credit: © Jonas Collén

The first red alga genome has just been sequenced by an international team coordinated by CNRS and UPMC at the Station Biologique de Roscoff (Brittany), notably involving researchers from CEA-Genoscope[1], the universities of Lille 1 and Rennes 1 and the Muséum National d'Histoire Naturelle[2]. The genome of Chondrus crispus, also known by the Breton name 'pioka', turns out to be small and compact for a multicellular organism. It has fewer genes than several other species of unicellular algae, which raises a number of questions about the evolution of red algae. This low number of genes could explain why these organisms never colonized dry land, unlike their green counterparts-from which all terrestrial plants are descended. These findings open up new perspectives on the natural history of algae and of terrestrial plants.

They are published online in the journal PNAS on March 11th 2013.

Chondrus crispus is a multicellular red alga of about 20 cm in length. It is very common on the rocky coasts of the North Atlantic where it plays an essential role as a primary producer in these ecosystems. Certain red algae are now used in the agri-food industry for the thickening properties of the carrageenans from their cell walls. These sulfated polysaccharides correspond to the food additive E-407, which goes into many desserts and other dishes. Beyond industrial applications, this first sequencing of a red alga genome sheds new light on plant evolution as a whole.

The Chondrus genome had some surprises in store for the researchers. With only 9,606 genes and 105 million base pairs, it is indeed very small for a multicellular organism. By way of comparison, the unicellular green alga Chlamydomonas reinhardtii has 14,516 genes, while the multicellular terrestrial plant Arabadopsis thaliana has 27,416. The Chondrus genome is also very compact, with each function generally corresponding to a single gene. Gene families are small, and genes closely spaced.

To explain these surprising characteristics, the researchers proposed the hypothesis that, more than a billion years ago, red algae experienced a massive loss of genetic material as a result of extreme environmental conditions. This dramatic event in their evolutionary history would have had many consequences. One result could be the loss of flagellar genes, still present in most other organisms and responsible for the motility of certain cells (such as the gametes during sexual reproduction in most organisms, including humans).

Had this massive gene loss never occurred, red algae might have extensively colonized the terrestrial environment, in the same way as green algae, which are the ancestors of all land plants. Yet this event-a real evolutionary bottleneck-has denied red algae the plasticity and genetic potential necessary to adapt to life on land.

The sequence of the Chondrus genome thus opens the archives of more than 1,500 million years of evolutionary history of terrestrial and marine plants. It provides a new basis for the study of red algae biology and is the first step in a program aiming to improve our understanding of the origin of life on Earth, the adaptation of red algae to their environment and the biosynthesis pathways of biomolecules of interest, such as carrageenans. The scientists of the group are also hoping to discover new enzymes of interest for marine biotechnology.

[1] CEA-Genoscope was in charge of the sequencing and annotation facility.

[2] Led by the research unit Végétaux marins et biomolécules (CNRS/UPMC), this study also involved the following French laboratories: Génomique métabolique (CEA/CNRS/Université d'Evry) at CEA-Genoscope, Glycobiologie structurale et fonctionnell'e (CNRS/Univ. Lille 1), Laboratoire d'océanographie microbienne (CNRS/UPMC), Ecosystèmes, biodiversité, évolution (CNRS/Univ. Rennes 1), Biologie des organismes et écosystèmes aquatiques (CNRS/Muséum National d'Histoire Naturelle/IRD/UPMC), Adaptation et diversité en milieu marin (CNRS/UPMC) and Génome et développement des plantes (CNRS/Université de Perpignan).


Story Source:

The above story is based on materials provided by CNRS (Délégation Paris Michel-Ange). Note: Materials may be edited for content and length.


Journal Reference:

  1. J. Collen, B. Porcel, W. Carre, S. G. Ball, C. Chaparro, T. Tonon, T. Barbeyron, G. Michel, B. Noel, K. Valentin, M. Elias, F. Artiguenave, A. Arun, J.-M. Aury, J. F. Barbosa-Neto, J. H. Bothwell, F.-Y. Bouget, L. Brillet, F. Cabello-Hurtado, S. Capella-Gutierrez, B. Charrier, L. Cladiere, J. M. Cock, S. M. Coelho, C. Colleoni, M. Czjzek, C. Da Silva, L. Delage, F. Denoeud, P. Deschamps, S. M. Dittami, T. Gabaldon, C. M. M. Gachon, A. Groisillier, C. Herve, K. Jabbari, M. Katinka, B. Kloareg, N. Kowalczyk, K. Labadie, C. Leblanc, P. J. Lopez, D. H. McLachlan, L. Meslet-Cladiere, A. Moustafa, Z. Nehr, P. Nyvall Collen, O. Panaud, F. Partensky, J. Poulain, S. A. Rensing, S. Rousvoal, G. Samson, A. Symeonidi, J. Weissenbach, A. Zambounis, P. Wincker, C. Boyen. Genome structure and metabolic features in the red seaweed Chondrus crispus shed light on evolution of the Archaeplastida. Proceedings of the National Academy of Sciences, 2013; DOI: 10.1073/pnas.1221259110

Cite This Page:

CNRS (Délégation Paris Michel-Ange). "Why red algae never colonized dry land." ScienceDaily. ScienceDaily, 20 March 2013. <www.sciencedaily.com/releases/2013/03/130320095036.htm>.
CNRS (Délégation Paris Michel-Ange). (2013, March 20). Why red algae never colonized dry land. ScienceDaily. Retrieved April 17, 2014 from www.sciencedaily.com/releases/2013/03/130320095036.htm
CNRS (Délégation Paris Michel-Ange). "Why red algae never colonized dry land." ScienceDaily. www.sciencedaily.com/releases/2013/03/130320095036.htm (accessed April 17, 2014).

Share This



More Plants & Animals News

Thursday, April 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Change of Diet Helps Crocodile Business

Change of Diet Helps Crocodile Business

Reuters - Business Video Online (Apr. 16, 2014) — Crocodile farming has been a challenge in Zimbabwe in recent years do the economic collapse and the financial crisis. But as Ciara Sutton reports one of Europe's biggest suppliers of skins to the luxury market has come up with an unusual survival strategy - vegetarian food. Video provided by Reuters
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) — A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. Video provided by Newsy
Powered by NewsLook.com
Thousands Of Vials Of SARS Virus Go Missing

Thousands Of Vials Of SARS Virus Go Missing

Newsy (Apr. 16, 2014) — A research institute in Paris somehow misplaced more than 2,000 vials of the deadly SARS virus. Video provided by Newsy
Powered by NewsLook.com
Raw: Three Rare White Tiger Cubs Debut at Zoo

Raw: Three Rare White Tiger Cubs Debut at Zoo

AP (Apr. 16, 2014) — The Buenos Aires Zoo debuted a trio of rare white Bengal tiger cubs on Wednesday. (April 16) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins