Featured Research

from universities, journals, and other organizations

Scientists turn snails into slug-like creatures

Date:
October 12, 2010
Source:
Universitaet Tübingen
Summary:
Biologists have re-shaped the body design of snails. Exposure to platinum results in the formation of an internal shell instead of the normal external shell. During embryogenesis of the freshwater snail a time slot of just one or two days determines whether the animals form an outer shell or not. Reprogramming of the direction of growth of the molluscs´ shell-generating tissue during this sensitive phase prevents the development of the usual convoluted shell. In lieu thereof a small hollow cone grows inside the body -- similar to whats happens in squids.

Marisa transformed.
Credit: Heinz Köhler and Irene Gust, Universität Tübingen

Biologists have re-shaped the body design of snails. Exposure to platinum results in the formation of an internal shell instead of the normal external shell. During embryogenesis of the freshwater snail, Marisa cornuarietis, a time slot of just one or two days determines whether the animals form an outer shell or not. Reprogramming of the direction of growth of the molluscs´ shell-generating tissue during this sensitive phase prevents the development of the usual convoluted shell. In lieu thereof a small hollow cone grows inside the body -- similar to whats happens in squids.

Related Articles


This new program has implications also for other organs: the gill is not located in a mantle cavity over the head, as usual, but rather no mantle cavity is formed at all and the gill remains at the posterior end of the visceral sac and floats freely in the water. These results which recently have been published in Evolution & Development by the group of Prof. Heinz Köhler and Prof. Rita Triebskorn from the Institute for Evolution and Ecology of Tübingen University, Germany, support the theory of 'macromutation'-based radical developmental shifts caused by modifications of signal transduction pathways which may have led to sudden body plan alterations during evolution.

Initially, the phenomenon of snail-slug conversion was discovered by Raphaela Osterauer, PhD candidate supervised by Heinz Köhler, while studying the toxicity of metal ions. Some years ago, the group had established a comparatively sensitive embryo toxicity test on the basis of developing Marisa eggs. When testing the noble metal platinum, which is released into the environment by abrasion from automobile catalytic converters, she found the embryos lacking a shell when being exposed to high concentrations of bivalent platinum ions. Further experiments revealed crucial relevance of exactly that small time slot in which the direction of growth of the shell gland´s tissue is defined. During one or two days only, this tissue is either programmed to evaginate and to form a shell-secreting mantle covering the dorsal part of the snail´s body or, alternatively in the presence of platinum, to invaginate into the gastropod´s body.

It is thus possible to spatially re-direct the shell-forming tissue with all irreversible consequences for the formation of the mantle and the shell and the position of the gill simply by a temporary exposure to platinum ions. After removal of platinum, the artificial slug embryos proceed with their development according to the new developmental program, hatch from their eggs, feed as usual, and do not change their new body plan anymore. They reach an age of more than half a year. During his time, an internal calcareous shell in the shape of a slightly bend, hollow cone grows inside of the body of these animals which remains after their death. Since also extant slugs, sea-slugs, and cephalopods bear small internal shells, the artificial Marisa slugs may serve as a model organisms to investigate the evolution of shell internalization. In recent studies, the Köhler and Triebskorn group was able to raise artificial slugs also in two only distantly related lung snail species.

The molluscs are not genetically modified by platinum -- they are no mutants. However, the scientists expect gene activity regulation to be modified. Similar, mutation-based modifications of gene regulation may have contributed to the evolution of different mollusc body plans and, consequently, the Tübingen research group now plans to concentrate on the analysis of platinum-sensitive gene activity during the early embryogenesis of gastropods.

The biologists assume that the artificial slugs do not occur in the field, since platinum pollution in the environment does not yet reach the concentrations necessary for snail-slug conversion.


Story Source:

The above story is based on materials provided by Universitaet Tübingen. Note: Materials may be edited for content and length.


Journal Reference:

  1. Raphaela Osterauer, Leonie Marschner, Oliver Betz, Matthias Gerberding, Banthita Sawasdee, Peter Cloetens, Nadine Haus, Bernd Sures, Rita Triebskorn, Heinz-R. K?hler. Turning snails into slugs: induced body plan changes and formation of an internal shell. Evolution & Development, 2010; 12 (5): 474 DOI: 10.1111/j.1525-142X.2010.00433.x

Cite This Page:

Universitaet Tübingen. "Scientists turn snails into slug-like creatures." ScienceDaily. ScienceDaily, 12 October 2010. <www.sciencedaily.com/releases/2010/10/101011090229.htm>.
Universitaet Tübingen. (2010, October 12). Scientists turn snails into slug-like creatures. ScienceDaily. Retrieved November 27, 2014 from www.sciencedaily.com/releases/2010/10/101011090229.htm
Universitaet Tübingen. "Scientists turn snails into slug-like creatures." ScienceDaily. www.sciencedaily.com/releases/2010/10/101011090229.htm (accessed November 27, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Thursday, November 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Classic Hollywood Memorabilia Goes Under the Hammer

Classic Hollywood Memorabilia Goes Under the Hammer

Reuters - Entertainment Video Online (Nov. 26, 2014) — The iconic piano from "Casablanca" and the Cowardly Lion suit from "The Wizard of Oz" fetch millions at auction. Sara Hemrajani reports. Video provided by Reuters
Powered by NewsLook.com
Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) — Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) — The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com
Feast Your Eyes: Lamb Chop Sent Into Space from UK

Feast Your Eyes: Lamb Chop Sent Into Space from UK

Reuters - Light News Video Online (Nov. 25, 2014) — Take a stab at this -- stunt video shows a lamb chop's journey from an east London restaurant over 30 kilometers into space. Rough Cut (no reporter narration). Video provided by Reuters
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:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

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