Archive for the ‘DNA Buzz Word’ Category

DNA testing may resume for refugees

Saturday, November 7th, 2009

According to a news article published by Associated Press, the American government is discussing the use of DNA tests once again for some foreign refugees seeking residence in the U. S. This may lead to reinstating the pilot program that found massive fraud among those claiming family ties to join relatives already in the U. S. during the Bush administration.

Known as Priority 3, the suspended pilot program was conducted between late 2007 and early 2008, which used DNA testing to verify the blood relationships among family based refugee applicants. The program found that nearly 90% of the family claims were fraudulent. The program initiated DNA testing on applicants from a few African countries including Somalia, Ethiopia and Liberia, who claimed biological relationships with each other and applied to reunite with their family members who had already resettled as refugees and legal residents in the U. S.

The program didn’t test those already in the U. S. because the State Department said the overseas applicants made up 95% of the applicants to the program. The testing started when suspicions of fraud were first raised among refugees in Kenya. Fewer than 20% of the cases confirmed the claimed family relationship, and a large proportion of the applicants refused to take part in the requested test.

There is not a specific standing DNA testing program in place in the United States targeted at immigration and refugee applicants. However, the immigration officers will request a DNA test to be performed on applicants when they are suspicious of the relationship, and the submitted proof is not sufficient to prove the claimed relationship. Although no decision has been officially made, the State Department said in a statement given to the media that the new procedures would likely include DNA testing.

Are you born noble, genetically?

Saturday, September 26th, 2009

Most recently, genetic scientists have done some research into the genetic composition of different castes in India to see if there is any genetic difference between them. Since the separation of castes in India has been so rigid, scientists started with this assumption that long time isolation of each group may have shown in their DNA. The rigidity of the system still present in rural India has also made many wonder exactly how long castes have existed.

The study by geneticist David Reich and colleagues, published in the September 24 issue of Nature, takes a new approach to understanding the genetic history of India.

Reich’s team examined more than 550,000 points across all segments of the human genome. In doing so, they hoped to obtain a more complete picture of Indian genetic history. The research team analyzed the DNA of 132 individuals from India and neighboring regions, dividing them into 25 distinct groups based on geography, caste and language. They calculated how genetically ‘closed’ each of these groups were. In the caste system it is rare to marry someone from another class, making caste societies very closed, or ‘endogamous.’ If this endogamy continues over many generations, it will leave a behind a genetic signature for scientists to discover.Reich and his team found such a signature, indicating a long history of endogamy in several of the groups. In fact, the research team calculated that the DNA of six of the groups can be traced back to just a few individuals who lived anywhere from 30 to more than 100 generations ago. Assuming a generation time of 25 years, that establishes the existence of the caste system in the range of 750 to more than 2,500 years ago — long before the British colonial era.

In a second analysis, Reich and his team examined how ancient migrations could have influenced the formation of castes. First the researchers divided the Indian groups into language families: Indo-European and Dravidian. Dravidian tongues, like Tamil and Malayalam, are mainly spoken in southern India and are believed to be a remnant of languages spoken by some of the earliest inhabitants of the region. Indo-European languages, like Punjabi and Urdu, are more common in the north. They are believed to have arrived with a migration of farmers from southwestern Asia or the Near East about 9,000 years ago.Reich and his colleagues then compared the genetics of each of the Dravidian and Indo-European groups to a sample of European DNA. The team reasoned that, if Indo-European groups were really descended from the farmers, they would show more genetic similarity to the Europeans than the Dravidians.Not surprisingly, the authors’ hypothesis held true. The Indo-European speakers, like the Kashmiri Pandit and Vaish, were more genetically similar to Europeans. And because the majority of the upper castes speak Indo-European languages, while the lower ones tend to be Dravidian speakers, there could be a relationship between the arrival of Indo-European people and the formation of caste structure. Further evidence that an ancient caste system has permeated through India for thousands of years.

Fishy species? DNA can tell

Monday, July 20th, 2009

Fishy species? DNA can tell

I never thought we could be eating fresh water tilapia instead of raw tuna as advertised in a sushi bar. But, according to this study conducted by two New York school girls, half of the time, we are eating substituted fish. Another study published in the science journal Nature also found that 77% of fish sold as red snapper were actually another species.

Apparently, substituted fish not only reveals unethical business conducts, but also presents some health issues. To help address this problem, FDA is teaming up with fishermen in the Alabama Deep Sea Fishing Rodeo to barcode fish species using DNA technology.

FDA scientists will be at the rodeo collecting samples of different species caught, and DNA from those samples will be used to create a genetic profile, or literally a DNA bar code, for each species. The DNA barcodes of the species in the FDA fish DNA database can then be compared against DNA found in any suspect fish served or sold anywhere in the U. S.

FDA is also collecting fish samples at other locations and from seafood shops across the nation.

So, next time, you shell out $9.95 for a grouper sandwich and wonder why it tastes like catfish; you have a way to find out. Simply send the sample to FDA, and let DNA tell the truth!