Tuesday, 5 June 2012


Thin-slicing study of the oxytocins receptor (OXTR) gene and the evaluation and expression of the prosocial disposition.
by Lauren Baxter
Based on the study; Kogan, Aleksandr (2011). "Thin-slicing study of the oxytocin receptor (OXTR) gene and the evaluation and expression of the prosocial disposition".PNAS : Proceedings of the National Academy of Sciences (0027-8424), 108 (48), p. 19189.

Otis Redding and Glen Campbell sang about it in the 60’s with “Try a Little Kindness/Tenderness”  and Frederick Buechner once wrote “compassion is sometimes the fatal capacity for feeling what it is like to live inside someone else’s skin”(1926) but could how kind you are be affected by a single gene. Surely one would believe personality traits are determined by a multitude of both genetic and epigenetic factors but could this single-gene paradigm be ultimately a defining factor in the evaluation and expression of the prosocial disposition.

 Scientists at the University of Toronto Mississauga, Canada have completed a study in which the behavioural manifestations were observed of the oxytocin receptor (OXTR) gene. A single-nucleotide polymorphism is defined as single base-pair site in a genome where nucleotide variation can be found. (Campbell, N. 2008)

In this instance, SNP rs53576 has been implicated in pro-social behaviour. Homozygous subjects carrying the G allele of the rs53576 SNP of the gene exhibit more prosocial behaviour than the respective A allele carriers. (Kogan, A. 2011) Largely involved in both social and emotional procedures, Oxytocin is a neuropeptide produced within the hypothalamus. (Sofronew, M. 1983; Bartz, JA. 2006) Within humans, experiments have been conducted that show an increase in oxytocin leads to an increase respectively with facets of prosociality including trust, generosity and empathy. (Kosfeld, M. 2005; Zak, PJ. 2007; Bazara, J. 2009) In comparison to individuals homozygous for the A allele, carriers of the G allele are at a decreased risk to develop autism and through methods of self-analysis, report higher levels of this prosocial disposition. (Tost, H. 2010)In a neurological sense, carriers of the G allele often have a larger hypothalamus and amygdala activity. (Tost, H. 2010)

In the present study, scientists subjected a sample of 116 observers to watch 20 second, silenced video clips of 23 target individuals with varying genotypes listening to a romantic partner reveal a personal experience of suffering. It was hypothesised that individual differences in the genotype would predict how prosocial observers judge target individuals; that carriers of the G allele would indicate pro-sociability through non-verbal displays and that variations in targets’ nonverbal displays of affiliative cues would account for said judgement differences. (Kogan, A. 2011)

Although undoubtedly, social traits are influenced by a multitude of factors, the variation in rs53576 is a certainly a contributing factor. The study concluded people with the ‘GG’ version of the OXTR gene were judged to be kinder than those with ‘GA’ or ‘AA’ versions due to those carrying said ‘GG’ variation displaying more non-verbal empathetic gestures. (Kogan, A. 2011) Overall, the results support the hypotheses and therefore the communicability of slight genetic variations and the influence of the human mind to recognize nonverbal displays connected with specific genotypes. However further research will need to be conducted in order to understand the pathways through which genes prejudice behaviour. Furthermore, what are the implications of this within humanity? Is gene therapy the answer to a more empathetic society? Or could the knowledge of gene expression become an impost on human relationships?


References and Further Reading
Barraza, Jorge A. (01.06.2009). "Empathy toward Strangers Triggers Oxytocin Release and Subsequent Generosity". Annals of the New York Academy of Sciences (0077-8923), 1167 (1), p. 182.
Bartz, JA. Hollander, E. (2006) The neuroscience affiliation; Forging links between basic and clinical research on neuropeptides and social behaviour. Horm Behav. 50:518-528.
Campbell, N. et al. (2008) Biology. 8th ed. Boston; Pearson Education Inc.
Inoue, T. et al. (1994) Structural organization of the human oxytocin receptor gene. J Biol Chem. 269:32451-32456.
Kogan, Aleksandr (2011). "Thin-slicing study of the oxytocin receptor (OXTR) gene and the evaluation and expression of the prosocial disposition".PNAS : Proceedings of the National Academy of Sciences (0027-8424), 108 (48), p. 19189.
Kosfeld, M., Heinrichs, M., Zak, P.J., Fischbacher, U. & Fehr, E. 2005, "Oxytocin increases trust in humans", Nature, vol. 435, no. 7042, pp. 673-6.
Soforoniew, M. (1983) Vasopressin and oxytocin in the mammalian brain and spinal cords. Trends Neurosci. 6:467-472.
Zak, PJ. Stanton, AA. Ahmadi, S. (2007) Oxytocin increases generosity in humans. PLoS ONE. 2:e1128.

Alcoholism - Is it a Genetic Mutation?


                                                                                                                 Mia Thannhauser

Alcohol dependence, also known as alcoholism, is considered medically as a disease. Its symptoms, as listed by the American Association for Clinical Chemistry (2010), include increased tolerance, cravings, loss of control and physical dependence. For decades, sufferers of the disease have not only experienced its harsh physical and psychological effects, but also discrimination and stereotypes created by society. In recent years, however, scientific research has revealed that the likelihood of developing alcoholism is increased by the possession of variations in certain genes (Arbor 2011). When variation occurs in two specific genes, unc-79 and GABRA2, it is thought that it influences alcohol sensitivity (O’brien 2010) and impulsive behaviours (Arbor 2011).

Gene mutations are permanent alterations to sequences of DNA sections of chromosomes (U.S. National Library of Medicine 2012). When mutations occur in genes, it can affect the cell or organism’s ability to function normal, therefore promoting alcoholism in humans.

The gene unc-79 in mice, as well as the human version of the gene, is a poorly understood gene thought to interact with a neuron called NALCN (O’Brien 2010). In studies with mice, the mice that possessed mutated unc-79 genes voluntarily chose alcohol over water when offered the two. The mutant mice also were highly more sensitive to the alcohol. When injected with pure ethanol, the mice blacked out for much longer than the non-mutant mice. These observations in mice are thought to arise from the unc-79 gene mutation, dubbed as Lightweight, altering the neuronal responses to alcohol governed by NALCN (O’Brien 2010).


The GABRA2 gene is responsible for the functioning of receptors in part of the mammalian brain called the insula (Arbor 2011). In a recent study, those with the variant GABRA2 gene demonstrated higher levels of impulsiveness when under distress, with high activation in the insula. This links to the idea humans, particularly females, turn to alcohol to relieve distress and anxiety (Arbor 2011).

Both unc-79 and GABRA2 gene variants are just some of the genes that contribute to the symptoms of alcoholism, but do not directly cause it. However, as alcoholics, their families and researchers attempt to discover its medical foundations, the discoveries of mutations in genes as alcoholism contributors is extremely significant for prevention, treatment and understanding of alcohol dependence.


Monday, 4 June 2012

Genetics in Cancer


Genetics in Cancer

Hello, everyone. Today, I shall discuss the topic of cancer or, more accurately, a recent advance in genetics that should assist us greatly in the fight against cancer. Cancer currently afflicts 112,300 Australians, and causes 39,000 deaths every year (Australian Institute of Health and Welfare 2008). You can see that this is quite an intolerably large figure. Luckily, scientists are becoming able to identify the specific genetic mutations that lead to individual malignant neoplasms (that’s just the smart-people name for cancerous tumours). This innovation lets us give more effective treatment, and undergo greater in-depth analysis of the origins of a cancer.

The University of Colorado
This technique is still in the early stages of development, so scientists are not even close to identifying all of the genetic mutations that cause all types of cancer. However, researchers at the University of Colorado Cancer Centre performed a clinical trial in 2010 in which they did actually manage to link genetic anomalies to cancer. In this case, they studied a particular rearrangement of genes inside the cancer cells of thirteen different lung cancer patients. The study involved testing a drug designed to target this ‘gene rearrangement’ (Camidge 2010).

Diagram of human lungs containing a tumour
These researches managed to show that the identification of genetic mutations in cancer cells allows cancer to be treated very effectively. To see just how effective it is, you can look at the results of the trial for one of its patients, 60-year-old Ellen Pulhamus. Before the study, she had five malignant tumours, which shrunk by 62 percent after just six weeks! In addition to that, another round of treatment brought down their size by a further 50 percent! (Brown 2010) Results as fantastic as these mean that oncologists should soon be able to move on from prescribing drugs that will only work for about one in ten cancer patients, and charge forward to the stage where they can determine exactly which patients will benefit from which treatments, by looking at the genes of their tumours (Brown 2010).

Tumours in a lung

Another goal of the researchers in this field is to try to use gene identification to trace cancer cell mutation back to its origins. This could allow the primary prevention of some cancers by exposing the kinds of lifestyles and environmental conditions that lead to them (Brown 2010). It may even provide current cancer patients with some peace of mind, in that they could find out the reason or reasons behind them being so sick.




Cancer is a tragedy that most of us will have to experience at some point in our lives, whether it be through having to endure it ourselves or witness it in someone close to us. The work done by researchers like those at the University of Colorado Cancer Centre will allow us to extend, or even save, a considerable number of lives, from within our species and perhaps outside it. With cancer being the prevalent calamity that it is, such an achievement will have far-reaching positive consequences for our entire race.





References

Australian Institute of Health and Welfare 2008, All cancers combined, viewed 18 March 2012, <http://www.aihw.gov.au/acim-books/>

Brown, J 2010, Advances in genetics give cancer fight a bright future, viewed 18 March 2012, <http://www.mb.com.ph/node/248618/advance>

Camidge, DR 2010, ‘Optimizing the detection of lung cancer patients harboring anaplastic lymphoma kinase (ALK) gene rearrangements potentially suitable for ALK inhibitor treatment.’, Clinical Cancer Research, vol. 15, no. 22, pp. 5581-90.



Colour Blindness




The incredible discovery of colour blindness by John Dalton in the early 1790’s has lead to many scientific explanations as to the cause of colour blindness. The importance of colour on earth is that it allows human being’s to accomplish tasks in everyday life. Colour vision deficiency affects 5% of males and 0.5% of females (U.S National Library of Medicine 2012). This deficiency is the inability to “see” certain colours, or different perception of colour (State Government of Victoria 2011).

The mechanism of colour vision is based on its absorption of light by visual pigments enclosed within the rod cells and cone cells, which is centralised in the photosensitive structure called Fovia; dense grouping of cone cells, situated in the retina; light sensitive tissue (CinemaSource 2002). Rod cells allow visualisation in low-level lighting, and cone cells are responsible for colour reception (University of Illinois of Chicago n.d.). In the Fovia, there are three types of receptor cells: blue cone (S cones – short wavelength), green cone (M cones – medium wavelength), and red cone (L cones – long wavelength) (Augustine ,GJ, Purves, D, Fitzpatrick, D, et al. 2001). Signals from the Fovia are delivered to the brain allowing visualization in colour through the human eye. The absence of one or more of these receptor cells leads to colour vision deficiency (University of Illinois of Chicago n.d.).

With 23 pairs of chromosomes in the human system, one pair is the sex chromosome where the receptor cells are situated. In a female there are two pairs of X chromosomes, and in a male there is an X chromosome and a Y chromosome (U.S National Library of Medicine 2012). The receptor cells are situated on the X-chromosome. The absence of one or more of the receptor cells is commonly due to a genetic error, known as ‘X-linked recessive genetic disease’, which mainly affects the sex chromosomes X and Y. This disease occurs in the sex chromosome where both copies of a gene must either be mutated or damaged (Health Grades Inc, 2012). Since colour blindness is due to a genetic error, it can be stated that colour blindness is genetically inherited.

For colour vision deficiency to be inherited, both the mother and father have to be carriers of this genetic disease. Inheriting this gene error is usually from mother (carrier) to son, because the mother is the carrier without having any diseases or symptoms of the disease. The likelihood of inheriting vision deficiency is fifty-fifty. However, males are more likely to inherit this trait because generally male cannot have a ‘bad’ X chromosome along with a ‘bad’ gene without getting the disease. Thus, an altered copy of the gene in each cell is enough to cause the disease. Whereas, females typically have a second ‘good’ X chromosome, thus making them the carriers. Therefore, a mutation is required in both copies of X-chromosome to cause the disease. (Health Grades Inc, 2012)

Without colour vision, there are many difficulties in everyday lives that a colour deficient person encounters, such as, traffic lights. This is why the discovery was important in that it has lead to research that lead to the invention of ‘corrective lenses’, which are glasses that are specialised for the specific type of vision deficiency and allows the individual to have normal vision. Therefore, allowing normal functioning in day to day activity.






Reference:

1.     Augustine ,GJ, Purves, D, Fitzpatrick, D, et al. 2001, NeuroScience: Cones and Color Vision, 2nd edn, Sinauer Associates, viewed 18th March 2012,

2.    CinemaSource 2002, ‘Chapter 1: Visual Color Theory’, Visual Color Theory, pp.3, viewed 18th March 2012,

3.    Colour Blindness, n.d., Colour Blindness Cure & Correction, viewed 18th March 2012,



4.   
Health Grades Inc, 2012, Inheritance and Genetics of X-linked Recessive Genetic Diseases, viewed 18th March 2012,



5.    Health Grades Inc, 2012, X-linked Recessive Genetic Diseases, viewed 18th March 2012,

6.    Sarcone, GA 2012, Color Blindness or Color Vision Deficiency, Archimedes’ Laboratory, viewed 18th March 2012,

7.    State Government of Victoria 2011, Colour Blindness, viewed 18th March 2012,

8.    University of Illinois of Chicago, n.d., Department of Ophthalmology and Visual Sciences, Color Blindness, viewed 18th March 2012,

9.    U.S National Library of Medicine 2012, Colour Vision Deficiency, viewed 18th March 2012,

10. U.S National Library of Medicine 2012, How many chromosomes do people have?, viewed 18th March 2012,



Commercialising the Pawpaw

Recent developments in genetic technology have brought the once commercially impractical pawpaw to possibly becoming a viable candidate for mass consumption. The common pawpaw, which quickly goes rotten and has many seeds which can deter consumers, is native to North America, and is currently only sold at small farmers markets due to distribution difficulties. (Shore, 2012)  A project, led by Kermit Ritland, and partnered with plant propagation firm Bevo Agro, will attempt to commercialise the fruit. The pawpaw produces large amounts of ethylene gas, acting as a hormone to trigger ripening in many fruits, and so causes the pawpaw to move from ripe to rotten approximately 72 hours after being picked. (Kenrick, 2009)

The first aim of the project is to produce a much slower ripening fruit. A gene has already been identified in the apple that controls the production of ethylene gas, and this candidate gene will be targeted in the pawpaw. Researchers plan to produce a slower ripening fruit through a selective breeding program rather than direct genetic manipulation. (Shore, 2012) The project will use natural variation in the gene that controls ethylene release, using several trees over multiple generations. The use of modern techniques, such as the ability to identify certain genetic markers before full maturity of the plant, gives researchers the ability to shorten the breeding process from possibly decades to several years. Studying these markers gives researchers vital information on the presence and prominence of these ethylene genes to cultivate and cross breed the plants with desirable characteristics. The ultimate aim is to produce plants with the effects of these genes reduced or even muted. (Shore, 2012)

The second aim of the project is to produce a seedless version of the fruit by inducing polyploidy, the same state which produces seedless watermelon. This requires a change in the number of chromosomes in the plant. The pawpaw is naturally a diploid, meaning it has two homologous sets of chromosomes. Polyploidy is the state of the cells having more than two homologous chromosomes. The plant is sterile as its gametes have a different chromosomal number to the gametes of fertile plants, preventing successful fertilization and therefore resulting in a plant that cannot reproduce and preventing the production of seeds. (Lowe & Pomper, 2005) Polyploidy can be induced by introducing chemicals such as colchicine into the cellular environment, which interrupts anaphase of mitosis, stopping proper separation of chromosomes. (Painter, 2011) As the plants are sterile, different methods must be used for propagation, and the project will most likely use techniques such as grafting to reproduce plants that naturally occur as seedless polyploids.

The project promises very exciting new horizons for its sponsors, although the actual results are far from being realized. Due to the relatively slow progress of a selective breeding program, and the reliance on natural variation in cultivated plants, results may be many years away, even with modern genetic techniques.

Will Steadmsn

Sunday, 3 June 2012

Gene Detection


Hi, I’m Nikki Rezk and on newscientist.com I found an article named “Blood Tests Won’t Stop Gene Cheats,” written by Andy Coghlan. The article was released recently and discusses the discovery of muscle-boosting genes that, if used by athletes for the purpose of performance enhancement, would be undetectable in both blood and urine tests. This is alarming as it opens a whole new window in the sport industry, by which professional athletes may be able to cheat their way to the top, by implementing genes to illicitly and unethically strengthen their muscles. An investigation into gene doping, carried out on lab mice, was found to show that the process could dramatically strengthen the muscles, and consequently improve the athletic performance, of these mice without it being detected in blood or urine tests.

Mauro Giacca, a scientist from a genetic engineering centre in Italy, undertook this investigation. Giacca was commissioned to perform this research by the Word Anti-Doping Agency in preparation for the Olympics, due to the startling discovery of gene doping. Specific muscle-boosting genes such as IGF-1 were thought to make muscles grow rapidly and work far more efficiently. Giacca tested the effects of this gene on two test mice groups. He had to inject the mice with a virus for the gene to implant into their muscle cells. So both teams were injected with the virus, but only one with the muscle-boosting gene. The physical ability of both teams was tested, and it was found that the doped mice swam 3 times the distance of that of the control group. Also, a muscle autopsy was done on the mice, which showed that the IGF-1 gene triggered 10 times the normal protein production rate in the muscles. Both the gene and the virus were detected in the muscle autopsy, but it was found that the virus, the gene and the protein that was produced was nowhere to be found in the blood and urine tests. These staggering results show that there may be a method whereby humans, including athletes may gene dope their muscles to improve physical performance and there would be no way of detecting it!

Fortunately, implanting muscle-boosting genes is still very complicated and technically challenging; so it is highly doubtful that athletes will use illicit gene implantation in the near future. Unfortunately, muscle biopsies cannot be done on athletes before competitions, as it is unwarranted and unethical, being a very physically straining operation that would impact on athletic performance. Scientists are now struggling and researching to find ways that these genes can be detected in blood or urine samples, so that high profile sport competitions, such as the Olympics can remain fair and ethical for all competitors. 

Friday, 1 June 2012

Human Milk


Human Milk
As we know, the concept of breastfeeding is vital to a child’s physical and mental development as it contains nutrients which no artificial formula can provide. Infants that are breastfed have a smaller chance of being diagnosed with illnesses (Queensland Health 2011) So the importance of breast milk can be seen, however these benefits are not just for infants. Breast milk is comparatively healthier and more nutritious for adults then bovine(cow) milk. As breast milk is not readily available for consumption, scientists in china have been able to 'genetically modify cows to produce human milk'.(Gray 2011)



To create cows that are able to produce 'human milk,' scientists cloned human genetics which where then added specifically into the DNA of Holstein dairy cows using a process called electrotransformation.(Yang 2011) Once these embryo's had been genetically modified with human genes, they were placed into surrogate cows. Once the genetically modified cows where born it was found that their milk contained lysozymes, lactoferrin and alpha-lactalbumin, which are all proteins that are found in human milk and have numerous health benefits.(Gray 2011)
Lysozymes is a positively charged protein which contains a single polypeptide of 130 amino acid residues in its structure. 'Lysozymes have the ability to protect humans from bacterial infections as they are a type of glucanhyrdolase which allow it to hyrdolyse bacterial cells walls.' It also strengthens the immune system making humans more tolerant to diseases. Both human and bovine(Cow) milk contain lysozymes, however there is a large difference of how much is present. In human milk there is 3-3000 mg/ml present whilst there is 0.05-0.22mg/ml of lysozymes present in cow milk. Apart from a large difference in how much lysozymes is present, 'the activity of lysozymes in cow milk is one tenth the activity in human milk.' So it can be seen that Lysozymes are able to kill bacteria and strengthen the immune system.
(Yang 2011)



Lactoferrin was also found in the milk and is a protein which consists of a single stranded amino acid. 'The number of immune cells in a humans body is increased by this protein'. A lack of lactoferrin has also been found to cause health problems. Like lysozymes, lactoferin can also be found in human and cow milk, however the concentration in cow milk is considerably less. It can be seen that Lactoferrin has numerous health benefits. (Kwait n.d.)



Alpha-lactalbumin is also found in human milk which provides a large percentage of whey protein found in human milk. Whey protein is also found in cow milk however that is provided by beta-lactoglobulin which is believed to cause allergic reactions in children. Alpha-lactalbumin has many health benefits such as aiding in mineral absorption as well as providing protection from dangerous bacteria. (Wyeth n.d.)






Human milk may provide health benefits that cannot be found in cow milk however the basic nutritional values are quite similar. As seen in figure 2, The researchers compared the human milk to normal cow milk and found that there was little difference in the fat, protein, lactose and solids in the milk. (Yang 2011)

So it can be seen that genetically modifying cow milk is a breakthrough which has numerous health effects . Human milk contains proteins such as Lysozymes, Lactoferrinand Alpha-lactalbumin which all have specific functions which have positive affects on human health. So by genetically modifying cows to produce human milk, a healthier milk can be consumed.




Reference List
1. Gray, R 2011, Genetically modified cows produce 'human' milk,
The Telegraph,
viewed 15 March 2012,
<
http://www.telegraph.co.uk/earth/agriculture/geneticmodification/8423536/Genetically-modified-cows-produce-human-milk.html >



2. Kwait, G n.d., Lactoferrin Nature's Premier Immune-Boosting Protein,
Viewed 17 March 2012,
<
http://intelegen.com/ImmuneSystem/lactoferrin.htm >

3. Queensland Health 2011,
Importance of breast feeding,
viewed 15 March 2012,
<http://www.health.qld.gov.au/breastfeeding/importance.asp >.



4.Wyeth n.d., What is alpha-protein: The Right Composition,
Viewed 18 March 2012,
<
http://www.wyethnutrition.com.my/$$Alpha-lactalbumin.html?menu_id=215&menu_item_id=10 >



5.Yang, B 2011, 'Characterization of Bioactive Recombinant Human Lysozyme Expressed in Milk of Cloned Transgenic Cattle',
vol. 6, no. 3, viewed 17 March 2012,
<
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0017593>