High yield in flood zones?

Every year floods destroy hundreds of hectares of rice plants in lowland regions of Southeast Asia. These floods force many farmers to grow a variety of rice plants, that have long stems. These plants however have a very low yield compared to the shorter stem rice plant varieties. Scientists at the Nagoya University have recently managed to isolate the genes which give deepwater rice varieties their long stems. The genes are called snorkel 1 and 2

They have discovered that as water levels rise, the deepwater rice plants release a hormone called ethylene which activates the genes snorkel 1 and 2 which in turn causes rapid stem growth. The higher the water rises, the more ethylene released. Scientists 'trialled this by inserting these two genes into non deepwater rice plants and found that they grew longer stems. It is hoped that this breakthrough will help farmers grow high yielding rice species in flood prone regions.

Original article from: http://www.newsdaily.com/stories/tre57i4t7-us-rice-floods/

Derek Ngoo 43054647

"Those Genes Suit Your Complection!"

by Lauren Smith (41741801)

With the incredible resources now available for mapping entire genomes comes the huge task of linking genotype to phenotype. Human skin pigmentation is one such area currently being investigated.

Skin Colour is determined by a combination of the thickness of one's skin and its level of melanin; the thicker one's skin, the 'yellower' it's pigmentation and the higher one's level of melanin, the darker one's skin.

Recent studies have identified specific single nucleotide polymorphisms (SNPs)which are genetic markers that impact the melanin biosynthesis pathway or melanosome biogenesis and hence skin pigmentation.

Such SNPs have been identified in the following genes:

TYR, TYRP1, OCA2, SLC45A2, SLC24A5
SLC24A4, IRF4, TPCN2, MC1R, ASIP, KITLG

This research has applications in fields ranging from the history of human evolution to treatment for albinos (humans with no melanin).

These findings are just a fragment of the slowly mounting evidence that Geneticists are beginning to understand the code which is the very language of life - DNA.

Reference list:
Sturm, R A (2009)Molecular Genetics of Human Pigmentation Diversity
US national Library of Medicine; http://www.ncbi.nlm.nih.gov

To find out more:

http://www.ncbi.nlm.nih.gov/pubmed/19297406?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DiscoveryPanel.Pubmed_Discovery_RA&linkpos=5&log$=relatedreviews&logdbfrom=pubmed

http://www.biosci.ohio-state.edu/~pfuerst/courses/eeobmg640/reading2skincolor.pdf

Related Articles of Interest:

http://www.marieclaire.com/world-reports/news/latest/black-white-skin

http://www.msnbc.msn.com/id/28471626/

Fragmented Mitochondrial DNA found in Human Body Louse (Pediculus humanus)

The human body louse (Pediculus humanus) is a common pest found throughout the world. A parasitic organism that feeds on blood, it is a known transmitter of diseases such as typhus and relapsing fever. Until recently lice were known primarily from their infamy but new research first published in Genome Research (http://www.genome.org/) has highlighted a remarkable feature in this species. Having analysed the mitochondrial DNA of the human body louse it has been found to be highly fragmentized. So far this is the first animal species that has shown this unique characteristic.

Normally in animals mitochondrial DNA consists of a circular chromosome that contains 37 genes. The length of this chromosome is ~16 kb long. The mitochondria in the human body louse instead had its DNA and all 37 genes contained in 18 minicircular chromosomes. While this is the first time an animal has been found with multiple mitochondrial "minichromosomes" they have been previously found in plants and some protists.

It has also been found that other blood sucking lice also share this characteristic but the type of lice that feed on the hair or dead skin of animals do not have fragmented mitochondrial chromosomes. This has sparked some discussion among scientists on whether evolution of these minichromosomes had evolved at the same time as these animals begun to feed on blood.

Shao, R., Kirkness, E & Barker, S 2009, 'The single mitochondrial chromosome typical of animals has evolved into 18 minichromosomes in the human body louse, Pediculus humanus' Genome Res. published ahead of print March 31, 2009, viewed 1/4/2009, http://genome.cshlp.org/content/early/2009/03/25/gr.083188.108

'Lice genomes pieces of a new puzzle', media release, 1/4/2009, http://www.biologynews.net/archives/2009/03/30/lice_genomes_pieces_of_a_new_puzzle.html

Dyslexia, a genetic probem?

Four independent studies from the United States, Germany, and England implicate two genes in fostering dyslexia. The genes contribute to early brain development.

Dyslexia, a learning disorder that afflicts at least 5 percent of elementary school children, is characterized by difficulties in perceiving sounds within words, spelling and reading problems, and troubles with written and oral expression.
Both of the newly implicated genes normally trigger production of proteins that assist neurons in migrating to appropriate destinations during brain formation. Each gene lies in a section of chromosome 6 that previous studies linked to dyslexia.
"Genetic testing for susceptibility to dyslexia is a realistic possibility in the future," says pediatrician Jeffrey R. Gruen of Yale University School of Medicine in New Haven, Conn.
A team led by Gruen found that variants of a gene known as DCDC2 frequently occur in individuals diagnosed with a serious reading disability but not in their immediate-family members who don't have a reading problem. The researchers studied 536 parents and siblings in 153 families, each of which contained at least one person with severe difficulties reading and spelling.

The new findings appear in an upcoming Proceedings of the National Academy of Sciences.
Gruen's group examined the DNA sequence within the crucial chromosome-6 region. DNA alterations specific to reading disability appeared only in DCDC2.
The gene's precise function remains unclear. After injecting neurons of rat embryos with a substance that inhibits DCDC2 activity, the investigators found that, as the animals' brains grew, those neurons migrated shorter distances than corresponding cells in healthy rat embryos did.
In laboratory tests on preserved human-brain tissue, Gruen's team observed high concentrations of DCDC2's protein products in areas that brain-scan studies had identified as active during both fluent and poor reading http://www.sciencenews.org/articles/20050430/bob9.asp).
A group led by geneticist Juha Kere of the Karolinska Institute in Stockholm has also found a strong association between variations within DCDC2 and severe dyslexia, as indicated by a pronounced spelling disorder. The team's study, slated to appear in the American Journal of Human Genetics, included 111 German families.
A pair of studies, both conducted in England, link dyslexia to variants of a second gene in the same chromosome-6 region. Laboratory tests indicate that this gene, KIAA0319, also influences early stages of neurons' migration.
A group led by psychologist Julie Williams of Cardiff University reported that specific variations of KIAA0319 frequently appeared in 223 youngsters with dyslexia but not in 273 children without reading problems. The scientists found no association between DCDC2 and dyslexia. They published their findings in the April American Journal of Human Genetics.
A comparably large study just completed by University of Oxford researchers has independently confirmed those results, Oxford geneticist Anthony P. Monaco told Science News.
In contrast, the U.S. and German studies uncovered no role for KIAA0319 in dyslexia. Differences among the populations with dyslexia that were studied or in criteria for diagnosing it may account for the divergent genetic results, Gruen says.
Several genes on chromosome 6 and elsewhere in the genome probably contribute to dyslexia, comments neuroscientist Guinevere Eden of Georgetown University in Washington, D.C. The involvement of DCDC2 and KIAA0319, with their role in brain development, makes sense in light of the subtle disruptions of neural activity that accompany dyslexia, Eden says.

References:
Cope, N. . . . and J. Williams. 2005. Strong evidence that KIAA0319 on chromosome 6p is a susceptibility gene for developmental dyslexia. American Journal of Human Genetics 76(April):581-591. Available at http://www.journals.uchicago.edu/AJHG/journal/issues/v76n4/42045/42045.html.

Further Readings:
Bower, B. 2005. Read all about it. Science News 167(April 30):280-281. Available at http://www.sciencenews.org/articles/20050430/bob9.asp.
______. 2003. Dyslexia's DNA clue: Gene takes stage in learning disorder. Science News 164(Aug. 30):131. Available at http://www.sciencenews.org/articles/20030830/fob1.asp.

Eat a plant, become photosynthetic!

Elysia chlorotica, pictured right, is a green sea slug that lives along the Atlantic coastline of the United States. What makes this slug so unique is that it is able to ingest a certain species of algae (called Vaucheria litorea), store the algae's chloroplasts in the cells lining its gut, then run on "solar power" (i.e. convert sunlight into energy) for much of its life. Plant? Animal? Or freak?

The very fact that this slug can photosynthesise from ingested chloroplasts is perplexing; you see, the chloroplasts themselves contain only enough DNA to encode for about 10% of the proteins required for photosynthesis. Rumpho and her team hypothesised that the sea slug incorporates some of the algal DNA into its own DNA in a process called kleptoplasty. It is still, however, unclear as to how this occurs, but one theory is that some algal DNA is absorbed, along with the plastids, in the slug's gut.

Rumpho and her colleagues first sequenced the plastid genome of Vaucheria litorea and confirmed that it lacks the full complement of genes needed for photosynthesis. Then, to demonstrate the fact that the predator does indeed incorporate algal DNA into its own DNA, they showed that the nuclear gene of oxygenic photosynthesis, psbO, is expressed in the nuclear DNA of the sea slug. Furthermore, it was revealed that the psbO of the V. litorea is identical to that of the E. chlorotica, but absent in the mitochondrial genome of the latter organism.

The researchers believe that many more photosynthetic genes are absorbed by the sea slug through its diet, but do not completely understand as to how such plant genes are activated within the animal's cells.

Original article:

New Scientist - Solar-powered sea slug harnesses stolen plant genes

Additional information:

PNAS - Horizontal gene transfer of the algal nuclear gene psbO to the photosynthetic sea slug Elysia chlorotica

Author:

Insoo Kim (42050911), BIOL1020 P2

Me and my Genome

Recently, a series of companies have just released that a full DNA scan providing all the knobs and whistles of genetic counselling and freezing incase of future developments, will now cost a mere $1000. This has been percieved as being the major step of making this sort of process widely available; by making it affordable to the general public.

Not to mention that there are very serious players involved in these companies. The biggest of
these is the company hosting the most used search engine, Google. It seems as if many of these large companies are showing keen interest in such ventures, putting pressure on the opposing authorities, often using monetary force.

"All three companies use DNA chips to read off hundreds of thousands of the most common single-letter variations in people's DNA, known as single nucleotide polymorphisms (SNPs). While this does not provide nearly as much information as sequencing the entire genome, these scans do offer people an unprecedented glimpse of their own genetic blueprint."


Ethical groups have always had a problem with such things, mostly because of the incredible amount of power given to mankind once released. The following video describes how it shouldn't necessarily be left up to scientists to make the decision, but rather the general public:

In the report, a number of willing volunteers participated in the DNA scan. The general outcome wasn't of any real concern at all. One of the subjects stated:
"My highest risk was for restless legs syndrome. I thought it was a joke! " and a few just liked to find out a bit more about there body, but were quite skeptical.

The frightening thing is the way this sort of thing finds a way to quietly 'sneak' into society. The easiest way for these things to slip under the radar are when people neglect to speak up. So, I challenge you all, to consider such things and to possibly re-evaluate current assumptions and take a stand on something. As the future scientists I think it is essential to speak out about such things and not let it to rest.


Lets not let this one slip under the radar.





Kurt Bornhutter. (42054311)