Navigation Links
Study of skates and sharks questions assumptions about 'essential' genes
Date:12/17/2011

Biologists have long assumed that all jawed vertebrates possess a full complement of nearly identical genes for critical aspects of their development. But a paper in the December 16 issue of Science with Benjamin King of the Mount Desert Island Biological Laboratory (MDIBL) as lead author shows that elasmobranchs, a subclass of cartilaginous fishes, lack a cluster of genes, HoxC, formerly thought to be essential for proper development.

Hox genes dictate the proper patterning of tissues during embryonic development in all bilateral animals, that is, those with a top and a bottom and a back and a front. In fruit flies, mutations in one Hox gene can lead to such miscues as legs growing where antenna should be. In mammals, Hox genes are required for the proper patterning of vertebrae and ribs. Hox genes are notable for being "co-linear," that is, the order they appear in the genome corresponds to the order of their expression in tissues of developing embryos from head to tail.

Fruit flies have one Hox cluster. In all the jawed vertebrates previously studied, scientists always found four copies of the Hox cluster. These clusters, named HoxA, HoxB, HoxC, and HoxD, are present in humans with roughly 10 genes in each cluster (39 in all). Prior to King's study, it was thought that all jawed vertebrates needed at least one gene from each of the four clusters for viable development. However, King and his colleagues call that fundamental assumption into question by offering compelling evidence that at least two elasmobranch fish, the little skate (Leucoraja erinacea) and the dogfish shark (Scyliorhincus canicula), lack the HoxC cluster.

King and his co-authors, Heather Carlisle and Randall Dahn from MDIBL and Andrew Gillis from Cambridge University, used high-throughput sequencing data to characterize all genes expressed in late-stage embryos from three cartilaginous fishes the elephant shark (Callorhincus milii), dogfish shark (Scylliorhinus canicula), and little skate (Leucoraja erinacea). Studies by other researchers have shown that the elephant shark, which is not an elasmobranch but rather represents a subgroup of cartilaginous fishes called holocephali, has all four Hox clusters. King's sequence data confirmed this. However, the dogfish and skate did not express any HoxC genes.

Searching a draft 26x-coverage genome assembly for the skate, King found all HoxA, HoxB and HoxD cluster genes, but none of the HoxC genes. A separate group of researchers recently reported that they could not find any HoxC genes expressed or in the genome of the dogfish using traditional cloning techniques.

"A goal of the field of evolutionary developmental biology is to learn how developmental processes evolved by comparing many organisms with one another," says King. "Our work illustrates the value of studying elasmobranch fishes to gain new insights. If elasmobranchs do not need HoxC genes to develop properly, we must consider the possibility that there is more flexibility in the role of the various Hox clusters than we previously thought."

Genome sequence data for the skate was provided by the North East Cyberinfrastructure Consortium (NECC), a group researchers from five states (Maine, New Hampshire, Vermont, Rhode Island and Delaware) that includes King, who are working to characterize the skate and provide training in bioinformatics to students and faculty in these states.


'/>"/>

Contact: Ann Cox Halkett
ann.coxhalkett@mdibl.org
207-288-9880 x132
Mount Desert Island Biological Laboratory
Source:Eurekalert

Related biology news :

1. Long-term study shows effect of climate change on animal diversity
2. £2 million study to reveal workings of dementia genes
3. New study looks to define evangelicals and how they affect polling
4. CU-Boulder study suggests air quality regulations miss key pollutants
5. Researchers study acoustic communication in deep-sea fish
6. Study reveals homeowner perceptions in fire-prone areas
7. Researchers study how pistachios may improve heart health
8. Study: urban black bears live fast, die young
9. New study indicates link between weight gains during pregnancy and dieting history
10. Study reveals specific gene in adolescent men with delinquent peers
11. Sweat it out: UH study examines ability of sweat patches to monitor bone loss
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/6/2017)... RAM Group , Singaporean based ... in biometric authentication based on a novel  ... to perform biometric authentication. These new sensors are based on ... Ram Group and its partners. This sensor will have ... and security. Ram Group is a next generation ...
(Date:4/18/2017)... Calif. , April 18, 2017  Socionext Inc., a global ... of a media edge server, the M820, which features the company,s ... recognition software provided by Tera Probe, Inc., will be showcased during ... at the NAB show at the Las Vegas ... ...
(Date:4/13/2017)... 2017 According to a new market research report ... Identity Administration, and Authorization), Service, Authentication Type, Deployment Mode, Vertical, and Region ... expected to grow from USD 14.30 Billion in 2017 to USD 31.75 ... ... MarketsandMarkets Logo ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... ... October 11, 2017 , ... Singh ... orphan drug designation to SBT-100, its novel anti-STAT3 (Signal Transducer and Activator of ... SBT-100 is able to cross the cell membrane and bind intracellular STAT3 and ...
(Date:10/10/2017)... (PRWEB) , ... October 10, 2017 , ... Dr. Bob ... at his local San Diego Rotary Club. The event entitled “Stem ... CA and had 300+ attendees. Dr. Harman, DVM, MPVM was joined by two ...
(Date:10/10/2017)... ... 2017 , ... The Pittcon Program Committee is pleased to ... who have made outstanding contributions to analytical chemistry and applied spectroscopy. Each award ... conference and exposition for laboratory science, which will be held February 26-March 1, ...
(Date:10/9/2017)... ... October 09, 2017 , ... ... of medical marijuana products targeting the needs of consumers who are incorporating medical ... takes place in Phoenix, Arizona. , As operators of two successful Valley dispensaries, ...
Breaking Biology Technology: