Featured Research

from universities, journals, and other organizations

How biodiversity arises: Single gene mutation during development can lead to differences in jaw shape, feeding strategies

Date:
May 26, 2014
Source:
University of Massachusetts Amherst
Summary:
A new study of how biodiversity arises shows how a mutation in a single gene in development can lead to different consequences not only in jaw shape, but how this leads to different feeding strategies. It is among the first to show how one genetic change influences trait development and function.

For these experiments, Hu and Albertson consider the fish skull not simply as a collection of bones, ligaments and muscle, but as a dynamic mechanical device capable of a complex range of movements. Preparation of a cichlid craniofacial skeleton in the ventral view. The bone is stained red and cartilage blue.
Credit: R. Craig Albertson

A new study of how biodiversity arises, by evolutionary biologists at the University of Massachusetts Amherst, shows how a mutation in a single gene during development can lead to different consequences not only in how an animal's skull and jaw are shaped, but how this leads to different feeding strategies to exploit different ecological niches.

The study in the cichlid fish model by Yinan Hu, a doctoral student in organismic and evolutionary biology, with his advisor Craig Albertson, is among the first to address how a single genetic change can influence both trait development and function. Results appear in the current early online issue of Proceedings of the National Academy of Sciences.

Until now, Albertson explains, the field of evolutionary developmental biology (evo-devo) has focused mainly on connecting gene-level changes with the evolution of different anatomical shapes, or morphology, but the field has been less successful in revealing how these anatomical changes influence how an organism performs in its specific environment. This has left a gap in understanding of what allows species to adapt to new environments.

"It is not the shape of an organism that determines fitness per se," he notes, "rather it is how an organism interfaces with its environment that determines its survival. Shape tells part of this story, but function gets you a lot closer to understanding how well suited an animal is to its surroundings. In this paper, I think we have extended the discussion of how genes and genetic variation influence ecological fitness."

For this work, Hu and Albertson combined traditional genetic mapping and experimental embryology to show how changes in the ptch1 ("patch1") gene, a member of the hedgehog signaling pathway, alter skull and jaw development in African cichlid fishes, leading to pronounced shape changes in the adult. They also modeled the skulls of these fishes to show how this genetic variation and its anatomical consequences predict differences in feeding mechanics.

African cichlids are an ideal model system for studying how biodiversity originates and it is maintained over time, Albertson says, because it is "unprecedented in terms of the number of species that have evolved in a brief period of geological time."

As Hu explains, "Patch1 is a well-studied gene involved in various aspects of building organisms over development. What we show is how differential deployment of this gene over development can lead to changes in the skull that should have pronounced effects on how that fish makes a living."

"One form of the gene helps to produce faster moving jaws that are better able to collect highly mobile prey. The alternate form leads to the development of jaws that are slower but more powerful, which is better for consuming hard prey. It accomplishes this by altering many bones in the head at once. In other words, these simple genetic variants should go a long way toward allowing organisms to carve out different ecological niches," he adds.

For these experiments, Hu and Albertson consider the fish skull not simply as a collection of bones, ligaments and muscle, but as a dynamic mechanical device capable of a complex range of movements. Specifically, they borrowed the mechanical engineering principal of four-bar linkages, a simple movable chain with four joints, to understand how genetically induced changes in the skull translate to differences in jaw movement efficiency.

Fish skulls are dynamic entities with many bony elements capable of moving independently of one another. Biologists have used mechanical engineering concepts to help make sense of this complexity. Hu and Albertson note in this study that genetic changes in ptch1 result in changes in the length of two of three movable links in this four-bar system. The result is two different skull forms with different predicted kinematics, or geometries of jaw motion.

Speaking to these changes in jaw shape and kinematics, Albertson says, "The effects of different ptch1 variants on jaw development may help to explain how this group has managed to evolve so many species in such a brief period of time. A single genetic change affects multiple skeletal elements in a way that influences feeding mechanics. Natural selection doesn't need to coordinate changes at multiple places in the genome to enable a species to adapt to a new environment. A small number of changes is likely sufficient to enable competing species to carve out different niches, enabling their coexistence. This is really the crux of biodiversity, how efficiently species are able to adapt in a changing environment."

While the effects of ptch1 on cichlid development described here are limited to the lower jaw, in another recent paper in Nature Communications Albertson and colleagues show how changes in a second well characterized molecular pathway can lead to functionally relevant changes in the cichlid upper jaw.


Story Source:

The above story is based on materials provided by University of Massachusetts Amherst. Note: Materials may be edited for content and length.


Cite This Page:

University of Massachusetts Amherst. "How biodiversity arises: Single gene mutation during development can lead to differences in jaw shape, feeding strategies." ScienceDaily. ScienceDaily, 26 May 2014. <www.sciencedaily.com/releases/2014/05/140526182649.htm>.
University of Massachusetts Amherst. (2014, May 26). How biodiversity arises: Single gene mutation during development can lead to differences in jaw shape, feeding strategies. ScienceDaily. Retrieved September 19, 2014 from www.sciencedaily.com/releases/2014/05/140526182649.htm
University of Massachusetts Amherst. "How biodiversity arises: Single gene mutation during development can lead to differences in jaw shape, feeding strategies." ScienceDaily. www.sciencedaily.com/releases/2014/05/140526182649.htm (accessed September 19, 2014).

Share This



More Plants & Animals News

Friday, September 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
Powered by NewsLook.com
Chimp Violence Study Renews Debate On Why They Kill

Chimp Violence Study Renews Debate On Why They Kill

Newsy (Sep. 17, 2014) The study weighs in on a debate over whether chimps are naturally violent or become that way due to human interference in the environment. Video provided by Newsy
Powered by NewsLook.com
Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
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