Gene for Coral Bleaching Discovered

Scientists from the University of Texas have identified a gene in coral that is affected when coral becomes heat stressed. Stressed coral release the algae they depend on for energy in a process more commonly known as bleaching. Bleaching results from unusual water temperatures, too warm or too cool, and causes coral to turn white in color. However, coral do not always die from bleaching and the process can be reversed if early enough in the process.

Photo from What is Coral Bleaching? NOAA

"We understood that there is a target gene essentially used as a biomarker for diseased and distressed corals, and that gene is induced by the response pathway that my lab studies," said Pellegrino, assistant professor of biology. Although Pellegrino never studied coral, he specializes in mitochondria and cell biology. 

The team at the University of Texas plan to do testing in a model organism in order to determine if the gene they discovered can protect coral from heat stress and infection. Coral reefs support 25% of all marine species on the plant. They provide habitats and shelter for marine life, aid in nutrient recycling, and protect coastlines from wave action and tropical storms. Laura Mydlarz from the Department of Biology says, “Understanding the existence of this gene means that there is now the potential to identify if corals are experiencing stress before they appear dead or bleached.” Researchers hope to be able to predict coral survival and identify if they are experiencing stress before the bleaching process occurs.

Honestly, I am on the fence about this gene discovery. It’s great because if scientists can prevent coral bleaching and extend the life of coral, I’m all for it. However, I feel like corals bleach because they cannot survive or function properly in the environment and expelling the algae living in their tissues is how they react to the stress. I think further studies need to be done to determine (a) if corals release the algae as a form of survival or response to not being able to thrive in said conditions, (b) if altering the gene will allow coral to continue living as it does in ideal conditions, and (c) how stressful situations affect the functions of coral.

Gene Editing Could Save Coral Reefs

A recent report has shown that using CRISPR-Cas9 scientists have been modifying genes in corals.  The research has been taking place in Australia using the Great Barrier Reef.  A research group led by Phillip Cleves used CRISPR to change three genes in the early life of coral just after fertilization.  Two of the genes were responsible for coloring for red and green fluorescent proteins and the last gene is involved with regulating how coral grows and settles in a reef.  The research is difficult to conduct because the coral only spawn once or twice a year for a very short period of time.  Getting the timing right was important because changing the genes in an early stage will make it easier for them to see how their changes affected the corals.  Scientists are hoping that this research could eventually lead them to make corals more resilient to bleaching caused by pollution and climate change.  Another hope is that they could eventually use this technology on existing coral and not just use it in the embryonic stage.

rebuilding coral reefs

Currently there is research going on in order to save the coral reefs. In Science Magazine, Warren Cornwall describes the research Madeleine van Oppen has been doing for a few years now in order to genetically change coral so that it is able to withstand higher seawater temperatures. A lot of the coral reefs around the world are dying due to global temperatures rising and an increase of carbon dioxide in the water. It is estimated that the seawater temperatures will increase another 3°C by the year 2100. One of the many problems the researchers at National Sea Simulator face is that coral only spawn once a year. Once the coral spawns, the eggs only survive a few hours if they aren't fertilized by sperm giving researchers a limited window of opportunity that only comes once a year.

It's very sad to read about how much coral we've already lost from The Great Barrier Reef as well as other reefs around the world. This research isn't just to genetically alter coral so that they can survive the increasing temperatures but also to find the stronger corals, ones that are able to survive the warmer water and coral bleaching, and continue to reproduce those in order to rebuild the reefs. There has been success with this research but not enough to stop the decay of the reefs.

Using CRISPR to Save Coral Reefs

CRISPR is a gene-editing tool (CRISPR-Cas9) that allows researchers to tweak any gene in plants or animals and the coral reefs could be the next target for this practice. Researcher Phillip Cleves and team at Stanford University published a paper in Proceedings of the National Academy of Science, in which they used the CRISPR technique to edit three specific genes in corals growing in the Australia Great Barrier Reef.

Australia's Great Barrier Reef is a major concern for coral life.

The genes that the researchers manipulated in the coral's early life cycle, just after the fertilization of egg via sperm. While the coral was a single cell, the genes were manipulated to ensure that all the subsequent cells of the coral would contain the manipulated genes. Two of the manipulated genes were responsible for reef coloring (using red and green fluorescent proteins) and the other regulates growth of coral.

The manipulation of genes to coral is difficult however, due to the reproduction behaviors of coral. Basically, coral only spawn once or twice per year, so the researchers had a very limited window. Results of the CRISPR experiment allow researchers to take more coral genes and determine what they do. Through this research, they may be able to cause coral to become more resilient to bleaching due to environmental conditions. The researchers claim that they will not use the research to genetically engineer the coral at this point, but are using it to develop a database of information. 

Personally, I believe in global warming and climate change and seeing the effects of it on our environment are disheartening. I also believe that coral reefs are not seen as important as they are. They are responsible and a key species in ecosystems. In addition, they help to protect coastlines from wave actions and provide habitats for marine organisms. Bleaching of the coral causes them to become weak and more susceptible to disease. This minor change can kill coral and cause a disruption in the ecosystem. I am totally for genetic engineering when it is ethically correct, and in this case, the use of engineering is to protect marine ecosystems and help to suppress the effect of global warming on the ocean. Over the next few years, I will be happy to see more research done on coral and their genes to try to protect the different species.

Caribbean Coral Reef Genetic Diversity may allow them to adapt to Climate Change

There are many species of corals in the Caribbean today, however this is probably only about half of what there used to be as half of all the coral species in the Caribbean went extinct between 1 and 2 million years ago and this was due to drastic environmental change in the conditions for which they are present. The Smithsonian Tropical Research Institute believes that one specific genus, Orbicella which was among the survivors of these environmental conditions will continue to adapt to climate change such as global warming. This is believed because this genus has high genetic diversity.

Fossils were collected from ancient coral reef systems and compared numbers of species at different time points. One of the best represented genus throughout time is Orbicella. In addition to looking at the fossil record, the researchers used genome sequencing to estimate past numbers of many species of Orbicella. This was done by taking one of two genetic material copies within an individual, sometimes one copy is different than the other and this is called a genetic variant. After sequencing the whole genome for a species currently found in Florida they were able to use this as a starting point and reconstruct genetic variation found in other individuals of past and present. With this information they were able to find the sizes of populations of different species throughout the past. This research showed Orbicella has been present in large quantities throughout time and has adapted to changes in its surrounding environment. This could be groundbreaking as many people believed coral reefs could be completely decimated in years to come with the effects of global warming. This study gives hope that maybe some can adapt to the more harsh conditions and allow for corals to be viewable by future generations.

New Genetic Data for Invasive Lion fish Populations

The popular belief was that the Red Lionfish was introduced to the Western World via an incident in Florida. New genetic research is indicating that that fact is false. The research suggests that there were multiple introduction sites throughout the Caribbean basin.

The red lionfish is a non-native invasive predatory species in the Western hemisphere originally from the Indo-Pacific region. Since they have no native predators in the Atlantic/Caribbean/South Atlantic they are quickly destroying habitats and wreaking havoc across already unstable marine environments, especially coral reefs.

This data is helping researchers track the Red Lionfish populations as well as if there are more/new introduction sites. The USGS recently conducted a survey taking animals from 14 countries within the Greater Caribbean Basin and Western Atlantic. The genetic differences between fish from difference sites are great enough to suggest they were dispersed from multiple introduction sites. This genetic data is helping scientists understand how the lionfish are spreading and what would be the most effective method of removal.

I think that this article was important because our coral reefs are already struggling with climate change as well as pollution as it is. The reefs do not need another factor to make them even more barren. It is important to monitor and control these populations as the lionfishes' ranges are beginning to expand past the warm tropical waters into more of the Northern Atlantic.

Link: http://www.sciencedaily.com/releases/2015/04/150423154631.htm

The Famous Colorful Coral Reefs

If you have ever seen the movie "Finding Nemo," then you will know about the famous and colorful coral reefs that line very small sections of the ocean floor. The coral reefs are home to about 25% of marine life world wide. But why are these coral reefs so famous and colorful? 

In a recent study conducted by scientists at the University of Southampton, the genetics of the colorful coral reefs have been studied. The study revels that the individual sections of living coral use one single gene to control pigment production to produce their colors. However, the corals do not just use one copy of the gene, the coral instead uses multiple copies of the same gene. The pigments act as sunscreen for the living organism and will create more or less depending on how much sun is on the reef. Another factor that affects the reefs are the many living organisms surrounding the coral. Most algae protect the coral from the sun through a symbiotic relationship.

This article was very interesting because I have always been fascinated with marine life and the coral reefs. The article does touch on why the coral reefs are dying out which I also thought was very interesting since part of it was related with the pigmentation.




found at: http://www.sciencedaily.com/releases/2015/01/150129094216.htm 

Adaptive Coral

A discovery made by researchers at the Center of Biological Research of the Northeast Cibnor, have found that certain types of corals have been adaptive towards the ocean’s acidification that has been increasing since the industrial revolution. This study was preformed along the Gulf of California and the coast of the Mexican Pacific because of its natural acidification. The researchers observed the radiographic plates, taken over a 22-year span, from samples of Porites panamensis. These images enabled the group to view the changes in extension, destiny, and calcification throughout time in the coralline skeleton. They even removed DNA from the coral to get a better understanding of its genetic diversity.

From the study, they were able to discover that the ocean’s acidification had not dramatically affected the coral’s growth, which also depends on the gender of the coral as well. Therefore not all corals are affected in the same way by the increase in acidification. The leader of the team, Eduardo Balart Paez, says that these corals are healthy for the moment because of it’s large energetic expense given by a genetic adaption. As the ocean turns more acid due to the rise in carbon dioxide emission released into the atmosphere, it is crucial for scientists to find out which coral species are able to adapt.  Artificial reefs do exist, but conserving natural reefs have a less adverse affect on certain species and maintains a stable ecosystem.    

Original article: http://www.sciencedaily.com/releases/2013/12/131202082404.htm