Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bone, enamel, dentine, milk & saliva share gene family

26.07.2004


Fish and mammal teeth are not created equal. Sometime after the move from spineless to having a backbone, the family of genes that controls tissue mineralization evolved to produce mammalian tooth enamel, bones and dentine, but fish enameloid developed from different genes, according to Penn State researchers.



"We also suggest that mammalian enamel is distinct from fish enameloid," the researchers reported in this week’s online edition of the Proceedings of the National Academy of Sciences. "The similar nature as a hard structural overlay on exoskeleton and teeth is because of convergent evolution." The researchers include Dr. Kazuhiko Kawasaki, senior research associate and Dr. Kenneth W. Weiss, the Evan Pugh Professor of biological anthropology and genetics, Penn State and Tohru Suzuki, professor of agricultural science, Tohoku University, Japan.

While similar structures and traits are often similar because they come from the same genetic basis, it is not unusual to have physical traits that look alike and serve the same purpose, developed from completely unrelated genes.


The genes responsible for bones, enamel, dentine, milk and saliva in most vertebrates belong to the same family; that is, they descend from a common ancestral gene, and for the most part, reside on the same chromosome. These genes are all responsible for calcium binding; whether it is the growth of bone on cartilage, tooth components like enamel and dentine, or production of calcium rich milk and saliva. However, all calcium-binding genes do not exist in all vertebrates.

"Birds have a gene to make hard egg shells, but they do not have genes for making tooth components," says Kawasaki. "Birds probably lost the enamel gene so long ago that there would be no trace of it."

The researchers have traced the development of these calcium-binding genes to a gene, SPARC, that existed before the split occurred between invertebrates and vertebrates during the Precambrian, 500 to 600 million years ago. Sometime after vertebrates arose, a gene called SPARCL1, or SPARC-like 1, developed and this gene is the ancestor of the family of genes that produce the wide variety of mineralized tissues.

Gene families develop because of tandem gene duplication, which occurs when two copies of one gene are copied onto a new chromosome. This error in duplication allows changes to occur in one copy of the gene, while the other copy remains unchanged and preserves the gene’s original function. Over time, the individual gene function slowly diverges.

"In any species, some of the duplicate genes could be incomplete or nonfunctional," says Kawasaki. "Others may be become specialized genes coding for things that exist in other vertebrates such as eggshell."

Penn State researchers were originally looking in this chromosome region for a genetic explanation of baboon tooth shape, where they found a series of genes with similar structures, but that all were involved in calcium binding.

Kawasaki used existing data on humans, mice, chicken and zebra fish along with data collected from the DNA of fugu or puffer fish to investigate this chromosome region.

"We also used our original fugu fish data to confirm that the databases were giving us the correct results," says Kawasaki.

The researchers used messenger RNA, the substance that contains the information for producing proteins to reverse engineer DNA that codes for these proteins. This copy DNA can be used to locate the original gene on the chromosome. Except for one of the three genes that codes for mammalian tooth enamel, all the other genes are found in the same area of the same gene. One of the enamel genes, AMEL, is found on the X and Y chromosomes in humans.

The gene that codes for fish enameloid however, is not related to this gene family and is not found on the same gene.

"Muscles, guts, nerves exist in both invertebrates and vertebrates," says Weiss. "But mineralized tissues such as bones, enamel and dentine are what make vertebrates different."

The split between invertebrates and vertebrates occurs during a time when there is a very spotty fossil record. Most estimates of the timing are done by molecular clock calculations.

The appearance of these mineral tissue genes after the split can shed light on the murky period when creatures developed backbones for internal support, sharp teeth for eating and protection, hard shells to protect developing young and milk to nurture them until they could use their teeth to catch and consume dinner.

"Now we are going to look to see if these genes are expressed in embryos when and where they are supposed to be expressed," says Weiss.

Andrea Elyse Messer | EurekAlert!
Further information:
http://www.psu.edu

More articles from Life Sciences:

nachricht Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View
22.06.2018 | University of Sussex

nachricht New cellular pathway helps explain how inflammation leads to artery disease
22.06.2018 | Cedars-Sinai Medical Center

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>