Key 'sleep gene' found by scientists

A team of scientists reported in the August 14, 2009 issue of Science that they have discovered the first gene involved in regulating the optimal length of human sleep. They identified a mutated gene that allows a mother and daughter to thrive on 6 hours of sleep. This is an exception to most humans who need a minimum of eight hours sleep to maintain optimal health. Professor Ying-Hui Fu, senior author of the study, says that “this finding offers an opportunity to unravel the regulatory mechanism of sleep.” Although the mutation is rare, scientists believe it may be a key to further understanding the regulatory mechanisms of sleep quality and quantity. If successful this could lead to treatments that provide relief for pathologies associated with sleep disturbance.

In the current study a mother and daughter were discovered to have shorter daily sleep requirements than most individuals. Blood samples were taken from both women and studied in Fu’s lab. A mutation was identified in a gene known as hDEC2. To further discover the impact of the study, the scientists genetically engineered mice to express the mutated gene. They studied the impact on their behaviour and sleep patterns. Both the genetically engineered mice and normal mice were deprived of 6 hours of sleep. When comparing the response of the two, scientists found that the engineered mice did not need to compensate for their lost sleep as much as the normal mice. “These changes in the mutant mice could provide an explanation for why human subjects with the mutation are able to live unaffected by shorter amounts of sleep during their lives” says Fu. The professor says that the next step is to identify the exact role of DEC2, as well as any physiological conditions associated with the mutated gene.

The article is available from: http://esciencenews.com/articles/2009/08/13/first.human.gene.implicated.regulating.length.human.sleep
For more information about the discovery, see the following article:
http://www.voanews.com/english/2009-08-13-voa54.cfm

Rare Genetic Mutation Allows for Less Sleep Each Night.

Sleep has always been necessary for survival. We have all been told that we need 8-9 hours sleep each night to function correctly. Recently a mother and daughter have been found to have a genetic mutation on the gene DEC2 that allows them to have only about 6 hours sleep each night. Even though this mother and daughter only get approximately 6.25 hours sleep a night, they still appear to be completely healthy.

Investigations have been done on this gene using transgenic mice. A mutation of the DEC2 gene was introduced to a group of the mice and they were found to need about 1.2hours less sleep each night than the control mice. In addition when the gene was removed from the mice it had an opposite effect and they slept quite a lot more.

Regulation of sleep has always been quite a grey area in science and the discovery of this new mutation may lead to new research. An associate professor, Mehdi Tafti, at the Center for Intergrative Genomics said that "In normal sleepers, if you reduce their duration to six hours, after a few days you will see some negative impact." This has been found to be different in 5% of the general population.

Source - http://www.scientificamerican.com/article.cfm?id=genetic-mutation-sleep-less
Image - http://blogs.denverpost.com/avs/wp-content/photos/sleep.jpg
Anna Di Mauro 42016663

Producing Better Crops

Soybeans are a widely used produce with a high global demand. There are several uses of soybeans, and these include, but are not limited to, various food additives and feed for livestock. In recent years over half the total harvest of soybean crops was genetically modified.

The three leading countries for soybean productions is the United States, Brazil and Argentina. The crops in the United States and Argentina are almost exclusively genetically modified. Due to their similarity, genetically modified soybeans are treated just like regular soybeans during harvesting, shipment, processing and storage.

Researchers are currently trying to determine ways of increasing and improving soybean crop longevity, size, durability, resilience and content. One example is the “Round Up Ready” soybeans which demonstrate these qualities. These particular soybeans have been modified to resist the weed killer, “Round up”. This allows the soybeans to continue growing once sprayed while neighbouring plants of different species are killed. These attributes are desired for better value on each harvest.

This is only one example of a genetically modified food, and there are many more that have had varying levels of success. This is due to the controversy that still surrounds the idea of genetic modification as some see it as ‘playing god’ and some countries have total bans on genetically modified foods.

Ryan Bayldon-Lumsden
42005519

Predicting Future Genes

Predicting Future Genes.

From Article: Molecular Ecology of Global Change
Article by: THORSTEN B. H. REUSCH and TROY E. WOOD

Recent studies on Global environmental change has found that there is evidence that it is altering the genetic traits for all biology; such information can be used to predict future genes in Organisms. The key factors as climatic variables and increase in CO2 concentration in the atmosphere were looked at. It was found that Genomes are susceptible to rapid evolution to global climate change at phenotypic genetic levels, as a response to changes in Ecological factors such as increase in CO2. The study finds that Genetic Traits that have mainly changed in model species are photoperiod responses, stress tolerance and traits associated with enhanced dispersal and reproduction. The genetic basis of changing traits with a defining role under climate change, stress tolerance and photoperiod behavior, is just recently starting to be understood for organisms, providing a point for selective gene approaches and future studies in targeted species.

The study has documented evolutionary changes are correlative, while in depth experiments that manipulate variables have been rare. These are Important for prediction because they provide large insight into heritable change to simulated conditions that exist today and may be present in the future. The growing knowledge available to molecular ecologists holds great promise for identifying the genetic basis of many more traits relevant to morph under global change. Moreover, knowledge of the genetic architecture of trait correlations should provide the necessary framework to aid understanding limits to phenotypic evolution; and allow greater understanding of metabolic costs and tolerance, in relation to climatic variations which forms linkages possibly causing negative trait correlations. Because adaptation to changing environment is always contingent upon the vast distribution of genes among earth’s species, high-resolution estimates of gene flow should be used to inform predictions of evolutionary changes that may be there to expect.


- Link to article:
http://www3.interscience.wiley.com.ezproxy.library.uq.edu.au/cgi-bin/fulltext/117989803/HTMLSTART
- Tables can be found via side tabs from article page


Student: Pranay Nath
42005854

Genetic Discovery To Eradicate Malaria?

Malaria is a disease that affects over 300 million people every year and causes over a million deaths. Current methods of control such as chemical sprays are proving ineffective, as seen in some areas of Africa, where malaria kills one child every 30 seconds.

Researchers have created a genetically modified (GM) mosquito that cannot pass on the malaria virus. By adding a gene into the mosquito's genome, the mosquito is resistant to the malaria virus and therefore cannot pass it on to a human or any other animal.

There is concern that these GM mosquitoes will not be able to compete with the malaria-carrying mosquitoes as the resistance gene will make them too weak to survive in the wild. However, tests have shown that GM mosquitoes slowly become the dominant species over time.

Scientists are currently focusing on methods to ensure the resistance genes are inherited by every offspring of the GM mosquitoes. If scientists can prove that the resistance genes will not have negative impacts on the environment, this may be a cheap and effective way to reduce the prevalence of the malaria virus.

Article Link:
http://www.theage.com.au/news/world/genetic-discovery-may-eradicate-malaria/2007/03/20/1174153063164.html

Annabelle Franklin
41754472

Noah the Gaur

A rare Asian ox called a Gaur was successfully cloned Sioux Center Iowa in 2003. It was successfully cloned and gestated in the womb of a cow which is a scientific first. The project was particularly interesting as it coupled cloning with that of interspecies birth. The researchers hope that technique may be able to to be used to shore up animal population.

The steps involved in this process are as follows.
1. Remove DNA from a unfertilized cow egg.
2. Insert full DNA strand from Gaur into the empty egg.
3. apply small electrical pulses to fuse.
4. Add chemicals to induce fertilisation events.
5. Place fertilized back inside cows uterus.

This process was repeated five times but only Noah made it to the late stages of fetal Development the other four were unfortunately spontaneously aborted. After Ten months of hard work by the scientists Noah the Gaur was born in Iowa. Unfortunately he died after 48 hours of life from Dysentry, "We don't think it had to do with the cloning,'Dysentery affects farm animals" Robert Lanza Vice president of scientific development at the center said.

Here is link to an interesting video on the cloning of Noah (warning video contains animal surgeries).

http://www.nature.com/stemcells/video/cloning/index.html

Skin Cells Cure Sickling in Red Blood Cells

Imagine if the cells of the largest organ in humans; skin cells could treat pateints with sickle cell anemia. This is no longer a possibility but a reality!

Sickle cell anemia is an inherited blood disorder that causes the body to produce abnormally shaped red blood cells. People with this disease are born with two sickle cell genes, one inherited from each parent. It is caused by the substitutuion of an amino acid in the protein sequence of hemoglobin. As a result, normally round blood cells become shaped like a crescent or sickle. These cells have short life spans compared to normal blood cell which causes the person to be anemic. Also, due to the abnormal shape, sickle cells often block blood vessels and thus reduce blood flow. This causes severe pain and various complications due to organ damage.

In a study published in Science by AAAS in 2007, scientists found significant evidence that supported the use of skin cells to restore the function of sickled red blood cells. In this study, three groups of mice were examined; control (normal mice), untreated (mice with sickle cell anemia but no treatment) and treated (mice with sickle cell anemia and treatment). Mice injected with humainsed sickle globin genes developed typical disease symptoms such as "severe anemia, urine concentration defects and overall poor health". From these mice, skin cells  from the tail were reprogrammed with gene therapy and cloned into induced pluripotent stem cells (iPS). iPS cells are genetically and developmentally similar to embryonic cells, wich are able to turn into all cell types. The iPS cells correct the sickle cell mutation by specific gene targeting. The genetically corrected iPS cells are then transplanted into sickle cell affected mice.

According to the results, the mice treated with iPS cells recovered 8 weeks after the transplant. The results of blood smears showed that treated mice had significanly lower amount of elongated or sickled cells compared to the untreated mice. Also, the blood count tests showed that treated mice had noticeable increases in red blood cell count and hemoglobin. There was also a definite reduction in sickle cell hemoglobin protein in treated mice, 4 to 8 weeks after transplantation.

Using iPS cells as a means of treatment has various advantages listed as follows:

1. iPS cells able to repair genetic defects

2. No requirement for unmatched transplanted cells (skin cells used from same person who is infected and so no compatibility problems)

3. Ability to use and convert iPS cells into any cell type for therapy

In conclusion, the treatment of sickle cell anemia by iPS cells of mouse skin cells is definitely a promising advancement towards curing sickled red blood cells in humans. Further research in this area is currently taking place, with a specific focus on reprogramming techniques in an attempt to reduce risks and developing reliable protocols for human iPS cells.

Reference:

2007, Hanna, et al. "Treatment of Sickle Cell Anemia Mouse Model with IPS cells generated from Autologous Skin", Science, American Association for the Advancement of Science, New York, Vol 318, pp1920-1923 < http://www.sciencemag.org/cgi/content/full/318/5858/1920 >

DOI: 10.1126/science.1152092

Images from Google images

Student Name:  Manal Masood

Student Number: 42028349