Contact Information:

Media Contact

Asuka Suzuki

Twitter: CRGenomica

Kredyty mieszkaniowe Kredyty mieszkaniowe

Sprawdź aktualny ranking najlepszych kredytów mieszkaniowych w Polsce - atrakcyjne kredytowanie nieruchomości. - Press Release Distribution
RSS - Press News Release
Add Press Release

Key genetic event underlying fin-to-limb evolution

A study of catsharks reveals how alterations in the expression and function of certain genes in limb buds underlie the evolution of fish fins to limbs

Key genetic event underlying fin-to-limb evolution
( A study of catsharks reveals how alterations in the expression and function of certain genes in limb buds underlie the evolution of fish fins to limbs. The findings are reported by researchers from Tokyo Institute of Technology (Tokyo Tech), the Centre for Genomic Regulation (CRG, Barcelona) and their collaborators in the journal eLife and give new insight into how fish evolved to live on land in the form of early tetrapods.

The first four-legged, land-living creatures - known as early tetrapods - evolved from fish, following the transformation of fins into limbs. This fin-to-limb evolution is a crucial, yet so far unsolved, example of how morphological changes can dramatically alter life on Earth. Now, researchers at Tokyo Tech and CRG, together with scientists across Japan and Spain, have revealed how genetic alterations governing the patterning of skeletal structures in fins may have led to the evolution of limbs and the rise of early tetrapods.

The forelimbs of tetrapod evolved from the pectoral fins of the ancestral fish. These fins contain three or more basal bones connected to the pectoral (shoulder) girdle. However, the most of basal bones located in the anterior side (i.e. the thumb side in the human limb) were lost in early tetrapods, and only the most posterior bone remained as the "humerus (i.e. the upper arm of humans)".

Pectoral fins of catsharks also contain three basal bones as seen in the ancestral fish (Fig. 1a). Thus, the team examined the fin development of catsharks, and revealed that there was a shift in the balance of anterior (thumb side) and posterior (pinky side) fields in their fin buds compared to that in mouse limb buds (Fig. 1a, below).

A key regulator protein controlling the balance of anterior and posterior fields of limb buds of tetrapods is Gli3. This protein is expressed in the anterior part of limb buds, and regulates the expression of a number of genes providing cells with information about their position along the anterior-posterior axis. For example, Alx4 and Pax9 are expressed in a small area of the anterior part of the limb bud, while Hand2 is expressed in a large area of the posterior field (Fig. 1b, below).

To determine whether shifts in the balance of anterior and posterior field occurred during fin-to-limb evolution, Onimaru, postdoctoral researcher currently at Sharpe's lab (CRG), and his colleagues carefully compared the expression, function and regulation of genes involved in anterior-posterior patterning in pectoral fins of catsharks, with those of mice. They found that, in pectoral fin of catshark embryos, Gli3 expression was intensified posteriorly, and the balance of the anterior and posterior fields was shifted (Fig. 1b, below). This indicates that a major genetic shift (posteriorisation) occurred as tetrapods evolved.

Furthermore, they found that the catshark genome lacked a sequence found in mice and other tetrapods, which is responsible for preventing Gli3 expression in the posterior part of tetrapod limb buds. As a known repressor, the restriction of Gli3 to the anterior may result in the loss of skeletal structure in this domain. When the researchers experimentally "posteriorised" pectoral fin buds of catsharks, the fins lost anterior skeletal elements, and showed a single bone connected to the pectoral girdle, as seen in fossil Tiktaalik pectoral fins (Fig. 2).

These results suggest that one of the key genetic events during the fin-to-limb evolution was a shift of the balance of the anterior and posterior fields (a "posteriorisation") and loss of anterior skeletal elements (Fig. 3). Further research involving genome-wide studies, particularly into the role of Gli3, will help explore these results more fully.


Background Fin-to-limb evolution and anterior-posterior patterning The earliest land-living creatures evolved from ancestral fishes, when fins transformed into limbs. Determining precisely how early tetrapods evolved, and in particular how fin-to-limb transformation occurred, has long proven difficult for scientists.

During limb development, the embryonic cells are allocated and determined for specific roles and positions, gradually building a correctly-formed limb. Part of this process includes so-called 'anterior-posterior patterning' - the determination of where individual parts of the limb bud develop along the anterior-posterior axis (thumb-pinky axis).

Previous research had divided the skeletal elements of shark pectoral fins into three parts along the anterior-posterior axis. In lobe-finned fish and tetrapods, however, two of the three segments - the anterior-positioned ones - had disappeared. This suggested that anterior-posterior patterning, and the genes which determine such positioning of skeletal elements, may play a key role in fin-to-limb evolution.

A key anterior-posterior patterning gene is Gli3 - a transcriptional factor which is known to control genes involved in creating fingers and toes, although little is understood about its full role in skeletal patterning of fins and limbs. Given its link to skeletal patterns, determining the exact role of Gli3 is an important future goal for scientists, and may prove invaluable in understanding fin-to-limb evolution.

Methodology To determine how fins evolved into the limbs of four-legged land-living creatures, Mikiko Tanaka and her team, from Tokyo Tech, used the latest genetic technologies to precisely track the expression, function and regulation of key anterior-posterior patterning genes in the fin/limb buds of both catshark and mouse embryos. They were then able to compare the fish and tetrapod genetic patterns, and uncovered a key difference between them in terms of fin/limb development.

They analysed expressions of anterior-posterior patterning genes, and found that the anterior field was larger in catshark fins than in mouse limbs. Then they found that the shift of the balance of the anterior-posterior field was caused by changes in transcriptional regulation of a key anterior-posterior patterning gene, Gli3. When Onimaru experimentally posteriorised the catshark fins, the resulting fins lost parts of their anterior skeletal elements and showed a single basal bone connected to the pectoral girdle.

Future work Future work involving systematic genome-wide studies would help expand on the current research. As mentioned, little is known about Gli3 regulation, even in mice, and so systematic studies of the precise genetics behind the development of limb skeletal structure is needed.

Reference Authors: Koh Onimaru1, 4, Shigehiro Kuraku2, Wataru Takagi3, Susumu Hyodo3, James Sharpe4, 5 and Mikiko Tanaka1
Title of original paper: A shift in anterior-posterior positional information underlies fin-to-limb evolution
Journal: eLife
DOI: 10.7554/eLife.07048
Affiliations: 1Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Japan, 2Phyloinformatics Unit, RIKEN Center for Life Science Technologies (CLST), Japan, 3Laboratory of Physiology, Atmosphere and Ocean Research Institute, University of Tokyo, Japan, 4EMBL-CRG Systems Biology Research Unit, Centre for Genomic Regulation (CRG), and Universitat Pompeu Fabra (UPF), Spain, 5 Institució Catalana de Recerca i Estudis Avançats (ICREA), Spain.

Tanaka Lab:
Sharpe Lab:

About Tokyo Institute of Technology As one of Japan's top universities, Tokyo Institute of Technology seeks to contribute to civilization, peace and prosperity in the world, and aims at developing global human capabilities par excellence through pioneering research and education in science and technology, including industrial and social management. To achieve this mission, we have an eye on educating highly moral students to acquire not only scientific expertise but also expertise in the liberal arts, and a balanced knowledge of the social sciences and humanities, all while researching deeply from basics to practice with academic mastery. Through these activities, we wish to contribute to global sustainability of the natural world and the support of human life. Website:

About Centre for Genomic Regulation The Centre for Genomic Regulation (CRG) is an international biomedical research institute of excellence, founded in December 2000 and based in Barcelona (Spain). The mission of the CRG is to discover and advance knowledge for the benefit of society, public health and economic prosperity. The breadth of topics, approaches and technologies at the CRG permits a broad range of fundamental issues in life sciences and biomedicine to be addressed. Nearly 380 scientists from 42 different nationalities work at the CRG on multidisciplinary projects, focusing on a broad range of topics: stem cells, epigenetics, cellular and developmental biology, genomics, cancer, systems biology, to name a few. Researchers receive strong support by cutting-edge technological platforms. Over 200 publications in high quality journals are published every year, and researchers are also active in facilitating the transfer of new basic findings into products for society.

The CRG is devoted to excellent training at all the stages of a career in life sciences. The CRG advanced training programme embraces training-through-research, hands-on and theoretical courses, conferences and seminars with leading guest speakers and internal data and journal clubs, to empower researchers with new skills, knowledge and abilities. The institute also runs Courses@CRG, a series of courses open to the scientific community and focusing on a wide range of topics combining theory and hands-on sessions. Career development and transferable skills are also provided through tailor-made training. The CRG runs a successful international PhD and Postdoctoral Programme (more than two hundred PhD students and postdocs), as well as a Summer Internship Programme, providing undergraduate students with the opportunity to carry out a research project during the summer period. Website:

[Attachments] See images for this press release:
Key genetic event underlying fin-to-limb evolution Key genetic event underlying fin-to-limb evolution 2 Key genetic event underlying fin-to-limb evolution 3


Patient satisfaction is a poor surrogate for quality of care in brain surgery

Patient satisfaction is a very poor proxy for quality of care comparisons in elective cranial neurosurgery. Because deaths are rare events in elective cranial neurosurgery, reporting of surgeon or even department-specific mortality figures cannot differentiate a high or low level of the quality of care. The current focus on patient safety in health care has led to public quality-of-care comparisons between health care facilities and even between individual health care professionals. In the United States, a new reimbursement method based on patient satisfaction ratings ...

Challenge to classic theory of 'organic' solar cells could improve efficiency

Challenge to classic theory of organic solar cells could improve efficiency
WEST LAFAYETTE, Ind. - New research findings contradict a fundamental assumption about the functioning of "organic" solar cells made of low-cost plastics, suggesting a new strategy for creating inexpensive solar technology. Commercialization of organic solar cells has been hindered by inefficiencies, but the findings point toward a potential path to create a new class of solar technology able to compete with standard silicon cells. "These solar cells could provide a huge cost advantage over silicon," said Muhammad Ashraful Alam, Purdue University's Jai N. Gupta Professor ...

Most comprehensive projections for West Antarctica's future revealed

Most comprehensive projections for West Antarcticas future revealed
A new international study is the first to use a high-resolution, large-scale computer model to estimate how much ice the West Antarctic Ice Sheet could lose over the next couple of centuries, and how much that could add to sea-level rise. The results paint a clearer picture of West Antarctica's future than was previously possible. The study is published today (18 August) in The Cryosphere, an open access journal of the European Geosciences Union (EGU). "The IPCC's [Intergovernmental Panel on Climate Change] 4th and 5th Assessment Reports both note that the acceleration ...

Possible test for liver cancer using technology for analysing rocks and minerals

A group of clinicians and geochemists are working to develop a test for the most common form of primary liver cancer, HCC (Hepatocellular Carcinoma). HCC kills over 600,000 people worldwide every year. It usually develops from chronic liver disease such as hepatitis or cirrhosis, but there is no good biochemical test to indicate when the cancer develops, meaning that even for patients most at risk, it is nearly impossible to know when a cancer may develop until symptoms appear. Now a multi-national group of scientists are developing a new test for HCC, based on methods ...

How having racially diverse friends can help you on the job

COLUMBUS, Ohio - Employees with a racially diverse group of friends outside of work may actually perform better at their jobs, a new study suggests. Researchers found that workers who had more different-race friends in their personal lives than their co-workers also tended to have a more racially diverse network of friends on the job. This broader network was linked to employees who did more tasks beyond their job responsibilities and who, under certain circumstances, had more trust in their supervisors. "Your friends outside of work actually have this connection to ...

Frequency of family meals increased by a new school presentation

This news release is available in French. This news release is available in French. New research shows that teaching young adolescents practical cooking skills leads to positive changes for the entire family. In an article published today in Applied Physiology, Nutrition, and Metabolism, an NRC Research Press journal (a division of Canadian Science Publishing), researchers evaluated the Kinect-Ed presentation and found an increase in the frequency of family dinners after participation. Kinect-Ed, a 90-minute motivational nutrition education presentation, was ...

Powdered cranberry combats colon cancer in mice

BOSTON, Aug. 18, 2015 -- Cranberries are often touted as a way to protect against urinary tract infections, but that may be just the beginning. Researchers fed cranberry extracts to mice with colon cancer and found that the tumors diminished in size and number. Identifying the therapeutic molecules in the tart fruit could lead to a better understanding of its anti-cancer potential, they say. The team will describe their approach in one of more than 9,000 presentations at the 250th National Meeting & Exposition of the American Chemical Society (ACS), the world's largest ...

Solar cell efficiency could double with novel 'green' antenna

BOSTON, Aug. 18, 2015 -- The use of solar energy in the U.S. is growing, but panels on rooftops are still a rare sight. They cost thousands of dollars, and homeowners don't recoup costs for years even in the sunniest or best-subsidized locales. But scientists may have a solution. They report today the development of a unique, "green" antenna that could potentially double the efficiencies of certain kinds of solar cells and make them more affordable. The researchers are presenting their work at the 250th National Meeting & Exposition of the American Chemical Society (ACS). ...

IU School of Medicine researchers report biomarkers and apps that predict risk of suicide

IU School of Medicine researchers report biomarkers and apps that predict risk of suicide
INDIANAPOLIS -- People being treated for bipolar disorder and other psychiatric illnesses are at greater risk of attempting suicide, but physicians may now have tools to predict which of those individuals will attempt it and intervene early to prevent such tragedies from occurring. Researchers at Indiana University School of Medicine reported Tuesday in the Nature Publishing Group's leading journal in psychiatry, Molecular Psychiatry, that they have developed blood tests and questionnaire instruments that can predict with more than 90 percent accuracy which of those patients ...

'Molecular tweezer' targets HIV and prevents semen from promoting infection

An unprecedented potential "molecular tweezer" called CLR01, reported in the journal eLife, not only blocks HIV and other sexually transmitted viruses, but also breaks up proteins in semen that boost infection. Semen is the main vector for sexual HIV transmission. It contains proteins that assemble into very stable polymers called amyloid fibrils, which can enhance HIV infectivity by up to 10,000 times. Scientists led by the University of Pennsylvania (USA) and Ulm (Germany) now show that a molecule with the shape of a tweezer not only destroys HIV particles but also ...


How your brain decides blame and punishment -- and how it can be changed

Uniquely human brain region enables punishment decisions

Pinpointing punishment

Chapman University publishes research on attractiveness and mating

E-cigarettes: Special issue from Nicotine & Tobacco Research

Placental problems in early pregnancy associated with 5-fold increased risk of OB & fetal disorders

UT study: Invasive brood parasites a threat to native bird species

Criminals acquire guns through social connections

Restoring ocean health

Report: Cancer remains leading cause of death in US Hispanics

Twin study suggests genetic factors contribute to insomnia in adults

To be fragrant or not: Why do some male hairstreak butterflies lack scent organs?

International team discovers natural defense against HIV

Bolivian biodiversity observatory takes its first steps

Choice of college major influences lifetime earnings more than simply getting a degree

Dominant strain of drug-resistant MRSA decreases in hospitals, but persists in community

Synthetic biology needs robust safety mechanisms before real world application

US defense agencies increase investment in federal synthetic biology research

Robots help to map England's only deep-water Marine Conservation Zone

Mayo researchers identify protein -- may predict who will respond to PD-1 immunotherapy for melanoma

How much water do US fracking operations really use?

New approach to mammograms could improve reliability

The influence of citizen science grows despite some resistance

Unlocking secrets of how fossils form

What happens on the molecular level when smog gets into the lungs?

Using ultrasound to clean medical instruments

Platinum and iron oxide working together get the job done

Tiny silica particles could be used to repair damaged teeth, research shows

A quantum lab for everyone

No way? Charity's logo may influence perception of food in package

[] Key genetic event underlying fin-to-limb evolution
A study of catsharks reveals how alterations in the expression and function of certain genes in limb buds underlie the evolution of fish fins to limbs is a service of DragonFly Company. All Rights Reserved.
Issuers of news releases are solely responsible for the accuracy of their content.