Navigation Links
Worm-like marine animal providing
Date:6/18/2008

Research on the genome of a marine creature led by scientists at Scripps Institution of Oceanography at UC San Diego is shedding new light on a key area of the tree of life.

Linda Holland, a research biologist at Scripps Oceanography, and her colleagues from the United States, Europe and Asia, have deciphered and analyzed fundamental elements of the genetic makeup of a small, worm-like marine animal called amphioxus, also known as a lancelet.

Amphioxus is not widely known to the general public, but is gaining interest in scientific circles because of its position as one of the closest living invertebrate relatives of vertebrates. Although amphioxus split from vertebrates more than 520 million years ago, its genome holds tantalizing clues about evolution.

The research led by Holland is published in the July issue of the journal Genome Research. A corresponding research paper is published in the June 19 issue of Nature.

Holland and her colleagues studied the genes of the amphioxus species Branchiostoma floridae through samples obtained in recent years during field work off Tampa, Fla.

Because amphioxus is evolving slowlyits body plan remains similar to that of fossils from the Cambrian timethe animal serves as an intriguing comparison point for tracing how vertebrates have evolved and adapted. This includes new information about how vertebrates have employed old genes for new functions.

"We are finding that today's complicated vertebrate has not invented a lot of new genes to become complicated," said Holland, of the Marine Biology Research Division at Scripps Oceanography. "Amphioxus shows us that vertebrates have taken old genes and recombined them, changed their regulation and perhaps changed the gene function."

Originally discovered in the 1700s, amphioxus appears fish-like with a small tail fin and medial fins, but no paired ones. They spend most of their time burrowed in sand, with their snouts extended for filter feeding.

The human genome has only about 25 percent more genes than the amphioxus genome, according to Holland. During evolution, humans have duplicated genes for different functions. Such duplication has given humans and other vertebrates a much larger "toolkit" for making various structures that are absent in amphioxus, including cells for pigment and collagen type II-based cartilage, for example.

In the new research, Holland and her colleagues describe success in probing the roots of important functions such as immunity. While vertebrates have two types of immune systemsinnate, which is a general first line of defense against pathogens, and adaptive, involving antibodies specific for particular pathogensinvertebrates like amphioxus have only innate immune systems. In amphioxus, several of these innate immune genes have been independently duplicated many times over. It may be that with a second line of defense, vertebrates, compared with invertebrates like amphioxus, are less reliant on innate immunity to ward off infection.

The neural crest cells of vertebrates are an excellent example of how "old" genes have acquired new functions. In all vertebrates, neural crest cells migrate from the developing neural tube throughout the body, giving rise to such structures as pigment cells, cartilage of the head and a number of other cell types. Although amphioxus has a brain and spinal cord and makes them using the same genes in the same way as vertebrates, amphioxus has no neural crest cells. Even so, amphioxus has all of the genes necessary for generating migratory neural crest cells; vertebrates have just put them together in new ways. It can be compared with a chef who takes basic leftovers in a refrigerator and whips up a fine gourmet dish.

"The take-home message from this sequencing is that the human and amphioxus genomes are very much alike," said Holland.

A collaborative effort of some 30 laboratories around the world solved the sequence of the amphioxus genome.

Further, deeper analyses between the amphioxus and human genomes in the years ahead will provide even more important clues about genetic evolution.

"All of this is just the tip of the iceberg," said Holland. "It will take a number of years for people to look in greater depth at the amphioxus and human genomes. In terms of figuring out what evolution has done and how it generally works, the amphioxus genome has really been a goldmine and will continue to be one in the years ahead."


'/>"/>

Contact: Mario Aguilera
scrippsnews@ucsd.edu
858-534-3624
University of California - San Diego
Source:Eurekalert  

Related biology news :

1. New study raises concerns about proposed mitigation strategy for marine bycatch
2. Queens marine biologist investigates aliens beneath the waves
3. Marine chemist says not so fast to quick oil detection method
4. Scientists reveal the lifestyle evolution of wild marine bacteria
5. New whale detection buoys will help ships take the right way through marine habitat
6. Arctic marine mammals on thin ice
7. Researchers to develop ocean sanctuary noise budget to evaluate potential impact on marine mammals
8. Pew Institute teams with Chantecaille Cosmetics to protect global marine life
9. Marine bacterias mealtime dash is a swimming success
10. International team announces discovery of massive Jurassic marine reptile
11. Can Dungeness crab and eelgrass help improve management of our marine resources?
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Worm-like marine animal providing
(Date:5/6/2017)... SINGAPORE , May 5, 2017 ... has just announced a new breakthrough in biometric ... that exploits quantum mechanical properties to perform ... new smart semiconductor material created by Ram Group ... across finance, entertainment, transportation, supply chains and security. ...
(Date:4/17/2017)... 17, 2017 NXT-ID, Inc. (NASDAQ: NXTD ... filing of its 2016 Annual Report on Form 10-K on Thursday ... ... available in the Investor Relations section of the Company,s website at ... website at http://www.sec.gov . 2016 Year Highlights: ...
(Date:4/11/2017)... Research and Markets has announced the addition of the ... ... grow at a CAGR of 30.37% during the period 2017-2021. ... prepared based on an in-depth market analysis with inputs from industry ... over the coming years. The report also includes a discussion of ...
Breaking Biology News(10 mins):
(Date:5/22/2017)... ... May 22, 2017 , ... Cancer diagnostics and ... booth B2 at the Association for Pathology Informatics Annual Summit at ... to demonstrating its Cancer Diagnostic Cockpit and Consultation Portal, Inspirata will present research ...
(Date:5/21/2017)... ... May 20, 2017 , ... CNSDose is ... trial and error process by finding the right antidepressant faster. CNSDose speeds ... doctor-patient relationship through a personalized approach to treatment. , A peer-reviewed ...
(Date:5/19/2017)... ... 19, 2017 , ... The University City Science Center is ... for commercialization, and who are affiliated with the 21 partner academic and research ... now in its tenth round, is the first multi-institutional proof-of-concept program for the ...
(Date:5/18/2017)... ... May 18, 2017 , ... ... The Tapas Cooking Challenge is a two-hour team-building package designed for groups of ... by Chef Jodi Abel, which include items, such as Blackened Shrimp with Edamame ...
Breaking Biology Technology: