Long Necks: The Answer is in The Giraffe's Genome

             In the article “Genome Reveals Clues to Giraffes 'Blatantly Strange’ Body Shape” scientists recently engaged in studying the genes of which are specific to a giraffe's height and other natural habits. Giraffes are part of a group of species called ruminant, among these species are cattle, sheep antelope etc., giraffes are unique animals among this group because of their enormous size. Prior to recent studies not much has been known about the giraffe. It wasn’t till 2016 when a composite of the giraffes genome project was put into place, called the Ruminant Genome Project. What researchers found was that there were a number of genes that not only regulate the rate at which giraffe bones grow but the circulatory function to which the blood travels 6 up into the animals brain. Giraffes genes show that their growth rate  is significantly faster than any other animal on the planet.

            The gene known as FGFRL1 was a very important gene because unlike other ruminants this gene was different in giraffes. This gene regulated bone growth and the ability for the giraffe to deal with hypertension. To test that the FGFRL1 did in fact regulate the blood pressure, growth and development, and multiple systems scientists used CRISPR to manipulate a group of mice's DNA with the gene. Results indicated mice whose DNA had been altered when injected with the  drug called angiotensin-II, did not suffer high blood pressure. A group of mice whose DNA was not manipulated when injected with the drug did suffer high blood pressure. This breakthrough had led to a possible hypothesis in which the gene FGFRL1 could lead to finding answers as well as new treatments for cardiac diseases in humans. Until further research is done I think that it is best to continue exploring the ruminants genome to find out other facts that have led to the evolution of giraffes. 

Genome Reveals Clues to Giraffes Strange Body Shape

 

When you think of a giraffe the first thing you think about is their really long necks. You might think a scientist knows how giraffes got their really long necks but its quite the opposite they know very little. What we do know is that giraffe bones grow faster than any human also the amount of pressure to pump blood up their necks would be fatal to a human. Isn't that crazy? Rasmus Heller and his group collected a giraffe genome and they identified almost 500 genes that were unique to giraffes or contain variants found only in giraffes. 

What the genes showed was how different giraffe genomes were from other animals genomes such as blood pressure regulation, growth and development, nervous and visual systems. Hundreds of genes observed and looked at but only one stood out the most the FGFRL1. This gene is the most divergent but also it has seven amino acid substitutions that are unique to giraffes. This gene is also found in humans which is involved in cardiovascular development and bone growth so this could be playing a role on why giraffe necks are so long.  

Picture is from article.

Giraffes Are Actually Four Species - Not One

The giraffe has been previously considered one species. However, recent research has proven that there are actually four, rather than one, species of giraffes. Giraffes were considered to be split into sub-species before the light of this knowledge based off of their different patterns of coat and their habitat. This study consisted of tracking seven different genomic sequences that researchers chose to study genetic diversity in the mitochondrial DNA from giraffes in Namibia. The mitochondrial DNA evidence displayed that there were distinct differences in four different groups and that these four groups of giraffes had not cross-bred to exchange genetic material for over millions of years. This was enough to prove that there were four distinct species of giraffes now, and there have been for a while. These four species are the Southern Giraffe (Giraffa giraffa), the Masai Giraffe (Giraffa tippelskirchi), the Reticulated Giraffe (Giraffa reticulata), and the Northern Giraffe (Giraffa cameopardalis). Each of these species may be adapted based off of their habitat or their diet. Conservationists believe that based of this information that these four species of giraffes need to be re-assessed for their conservation status. Previously, they were considered a single species, so this data may change the status of them as "Least Concern" to a more threatened status. The four tallest species of mammals are the four recently-discovered giraffe species.

The science in this article indicates that for over a million years these giraffes have been separated into distinct species, yet we have only now discovered this information. This is a reminder that conservation science always is learning new information and there are many strides still to be taken to protect the species of our planets. A giraffe is an animal that everyone knows of, but this proves how much we still do not know about them. This makes me question the species of giraffes we may not have known that have gone extinct to due overlooking them as separate species. These gentle giants need our recognition and to be paid attention to because of their 70% decline in population over the last fifteen years. The mitochondrial DNA that was the sample studied is the same DNA that is studied in ancestry testing in humans. It is interesting to see the vast number of information stored in our DNA and the different ways we can use that information to further our understanding of life around us. 

Works Cited

Department of Health & Human Services. "Mitochondrial DNA." Genetics Home Reference. U.S. National Library of Medicine, June 2016. Web. 20 Nov. 2016. <https://ghr.nlm.nih.gov/mitochondrial-dna#resources>.

DNA Diagnostic Center. "What Is Mitochondrial DNA (mtDNA) and How Is It Used?" Paternity & DNA Testing. DNA Diagnostic Center, 22 Sept. 2014. Web. 20 Nov. 2016. <https://www.dnacenter.com/blog/mitochondrial-dna-mtdna-used/>.

Fennessy, J., and D. Brown. "Giraffa Camelopardalis (Giraffe)." The IUCN Red List of Threatened Species. International Union of Conservation of Nature, 2010. Web. 20 Nov. 2016. <http://www.iucnredlist.org/details/9194/0>.

Gill, Victoria. "Giraffe Genetic Secret: Four Species of Tallest Mammal Identified." BBC News Science & Environment. BBC News, 8 Sept. 2016. Web. 20 Nov. 2016. <http://www.bbc.com/news/science-environment-37311716>.

Morell, Virginia. "Inside the Fight to Stop Giraffes' 'Silent Extinction'" National Geographic. National Geographic Society, 25 June 2015. Web. 20 Nov. 2016. <http://news.nationalgeographic.com/2015/06/150625-giraffes-animals-science-conservation-africa-endangered/>.

A Quadruple Take on the Giraffe: There are Four Species, Not One

Scientists used to think that there was only one species of giraffes but they now know that there are four species. Dr. Axel Janke, a geneticist from the Senckenberg Biodiversity and Climate Research Center, along with Julian Fennessy from the Giraffe Conservation Foundation in Namibia and their colleagues tested the DNA of almost two hundred giraffes from across Africa. They found genetic mutations that were present in some groups of giraffes, but were lacking in others. Before giraffes were just classified as Giraffa camelopardalis, but now they will be one of four species: the southern giraffe, the Masai giraffe, the reticulated giraffe, and the northern giraffe. A few differences between the giraffes include jagged lines and dark spots on the Masai giraffe or the five horn structures on the northern giraffe, but most of them look the same for the most part. According to Dr. Janke, the species might have diverged from one another about 1.5 million years ago. They do not know why it took so long to figure out that giraffes have four different species, but he thinks it may have something to do with the fact that there are not studied as much as other African wildlife such as lions, elephants, and rhinos. Giraffes are my favorite animal, so when I saw this article, I knew that I had to read it. It is crazy to think that there are now four different giraffe species because they all look more or less the same on the outside. It is shocking that it took so long to find out that there are multiple species of giraffes, but it does make sense if they were not studied as much as other African wildlife.

Giraffe genome reveals clues to sky-scraping height

Giraffes are the largest land animals on the planet. Scientists were able to sequence the genome of the giraffe as well as its cousin, the okapi, to unravel the genetic mysteries behind the animal's unusual physical features. Because these two animals have different physical features from one another and they are the only current living members of the Giraffidae family, the okapi genome makes the perfect screen for identifying things that were unique in the giraffe. Douglas Cavener of Penn State worked with an international team of colleagues to sequence the whole genome of a species of giraffe as well as an okapi. They compared the protein-coding regions of the giraffe and okapi genomes to see how they differed. The scientists then compared the giraffe and okapi genes with several other animals like cattle and mice to observe the genetic differences that separate them from other mammals. The scientists identified 70 genes with variations that are unique to giraffes. Half of the genes have been found to regulate growth and development. A mutation of one of the 70 genes causes defects to both cardiovascular and bone development in humans and mice.

The next step according to geneticist Hopi Hoekstra is to run tests to see whether the giraffe gene variants produce the physical differences that the researchers predict. Until the scientists inspect the non-protein coding regions of the giraffe, they are still far away from discovering what makes a giraffe a giraffe. However, this study needs to be completed soon since the numbers of giraffes are decreasing dramatically. The population of giraffes in Africa have declined 40% since 2000.

I really liked this article! When I was on my senior trip to Disney World in high school, I went on the safari ride at Animal Kingdom and the tour guide told us that the giraffe and okapi were closely related and I had a hard time understanding how due to their physical features. However, with the help of genetics and this study, I learned more about the genetic mysteries and differences between the giraffe and okapi. I also found it astonishing that there is a mutation in the genes of giraffes that causes defects to humans bones as well as cardiovascular system. I really hope that the number of giraffes in the world stop decreasing for the sake of this experiment to continue as well as the fact that they are such an amazing and beautiful creature.