I just happened across a new site called DnaTube.com Scientific Video Site. According to the website:
“DnaTube is a scientific research site providing video based studies, lecturers and seminars. Our goal is to contribute science by generating self-growing community who shares their scientific experiences. Most of DnaTube members are graduate students from universities of all countries.”
There’s a very brief introduction to DNA, genes, and inheritence.Â Even better, I watched a FASCINATING video showing the 3D structure of a mitochondria.Â For anyone who’s purchased a mtDNA genealogy test, this is a great video to understand more about mitochondria. I also watched a very cool video about red blood cells.
It looks as thought DnaTube is just starting, so check back often to see what’s new and interesting.
The CCR5 gene encodes a chemokine receptor (a long name for a protein that sits in the walls of our cells).When the body has been invaded by a pathogen such as a cold virus, CCR5 plays an important role in fighting that virus.Smart viruses such as HIV-1, however, hijack the CCR5 protein and use it to sneak into CD4+ T cells & macrophages.
In some populations the CCR5 gene has experienced a mutation that deleted 32 basepairs in the gene sequence.The mutation prevents the expression of the protein on the cell surface.As a result, people with this mutation show some degree of protection from certain viruses.In fact, homozygosity of the CCR5-D32 allele (meaning BOTH copies of the gene are mutated) leads to “nearly complete resistance to HIV-1 infection.”People with only 1 copy are as much as 70% resistant! Surprisingly, homozygotes do not show any other problems as a result of the mutation.
My first foray into genetic genealogy took place in 2003 when I ordered the mtDNAPlus (which sequences both HVR1 and HVR2) from Family Tree DNA.
Like so many other genealogists, I had been unable to trace my maternal line as far as I would have hoped.My most distant ancestor, Sarah L. Bodden, was born in 1846 in the Cayman Islands and had died in 1914 in Honduras.No one knew anything about Sarahâ€™s parents or her life, and given the location and the difficulty of research I felt that this line had little prospect of development.It was a perfect opportunity to employ genetics.
Inside (almost) every one of my 50 trillion cells (thatâ€™s 50,000,000,000,000!!!) there is a tiny circle of DNA that has been given to me, most likely unchanged, in a direct line from Sarah through 125 years, 5 generations, and across 1750 miles.By sequencing a small part of the DNA I could identify from which branch of the â€œmaternal family treeâ€ Sarah descended.Based on the information I had managed to put together, I predicted that Sarah was a descendant of English immigrants who settled the Cayman Islands and would thus possess mtDNA belonging to a European lineage.
Senator Edward Kennedy (D-Massachusetts) proposed a piece of legislation before the United States Senate on 1 March 2007 called the â€œLaboratory Test Improvement Act.â€The Act is proposed as a series of amendments to the Federal Food, Drug, and Cosmetic Act (FFDCA).
Sen. Kennedyâ€™s statement(pdf) before the Senate, found in the Congressional Record from this month, defines his goal as â€œ[ensuring] the quality of clinical tests used every day in hospitals and doctorsâ€™ offices across the country.â€Additionally, he pointed out that the â€œtests are being used to diagnose illnesses, predict who is most susceptible to specific diseases, and identify persons who carry a genetic disease that they could pass on to their children.â€
The Daily American Newspaper in Somerset, Pennsylvania, recently highlighted a family surname study being conducted through a local forensics company.Â The Eustace/Eustis/Eustice surname Y Chromosome DNA study began in July 2006 and according to the news article the project has tested 80 men in eight countries, a remarkable number.
Ron Eustice, one of the leaders of the study and editor of the Eustice Families Post newsletter emphasizes the importance of DNA to his genealogical research:
â€œMost family historians have spent countless hours poring over genealogical records, trying to connect the dots.Â DNA testing is rapidly establishing itself as the newest and perhaps most reliable tool in the field of family history research. I believe that including DNA evidence is an essential part of family history research.â€
Argus BioSciences, located in Belmont, California, is an up-and-coming company offering DNA sequencing for the study of genetic genealogy.Founded in 2003 by Dr. David Whyte, the company offers mtDNA sequencing and haplotype determination.
Although Argus is currently (as of March 2007) offering only mtDNA testing, all products are being offered at a greatly reduced rate.Sequencing of the hypervariable region (which includes HVR1-3) is offered for only $125.00 (regularly $149).You can compare this price to those offered by other companies in my DNA testing company comparison chart.Additionally, Argus is offering complete sequencing of the entire mitochondrial genome (16, 569 bases) for $345 (regularly $695).The company will also accept four monthly payments of $95 to pay for a full sequencing (to inquire, contact Argus at firstname.lastname@example.org).Currently only one other company (Family Tree DNA) offers complete mtDNA sequencing as a regular product.
The last time I counted there are at least 21 unique companies offering DNA testing for genealogical purposes, either Y-chromosome, mtDNA, or autosomal testing (see the Sidebar to the right for a listing).Â To get a clearer picture of what each company offers I created a master list of every company and the services they offer.Â See here.
While compiling the list I also gathered information about the markers that each Y-chromosome test analyzed.Â See here.Â There are of course the standard markers offered by most companies as well as the markers offered by only a single company.Â What company have you been tested by?
AncestryByDNA is a popular genetic test developed by DNAPrint Genomics, Inc.The company offers a variety of genetic testing, including Y-chromosome and mtDNA ancestry.They are most well-known, however, for their two admixture tests.Admixture tests examine SNPs, or single nucleotide polymorphisms, in the 22 autosomal chromosomes in each of our cells.Although every humanâ€™s DNA is 99.9% identical, the 0.1% differences make each one of us unique.Researchers have noticed that people in a particular region often have a mutation in common, one that people in most or all other regions of the world do not have.These usually harmless mutations, called SNPs, are believed to have bio-geographic properties â€“ people endogenous to certain regions of the world have different versions of the SNPs.A person who submits his DNA for analysis could have SNPs which reveal genetic contributions from a wide variety of regions.
How many founding Asian groups braved their way across the Bering land bridge during those frigid Pleistocene ice ages?Was it a single wave of people who later developed into the three distinct linguistic and cultural groups that populated the Americas, or were there multiple waves of people each with their own language and culture? Or was it some mix of the two?The issue has been and continues to be a topic of debate.
Linguistic studies of the Na-dene, Aleut-Eskimo, and Amerind language groups suggested that there were three waves across the land bridge, one for each language group.Recent genetic research, however, has suggested that there was only a single wave of founding groups into the Americas. (Read a free online review here).
With the arrival of Black History Month and following on the heels of PBSâ€™s popular series â€˜African American Livesâ€™, increasing numbers of African Americans are deciding to explore the world of DNA testing and genetic genealogy.As a result many newspapers and magazines are taking the opportunity to introduce their readers to this increasingly popular avenue of genealogical research.
The Rocky Mountain News in Denver, Colorado is currently three articles into a six-part series examining the role and effect of genetic genealogy in African American research [Thanks to Genealogy Reviews Online]:
Saturday, 17 February 2007 (Two articles, here and here).
Monday, 19 February 2007
Tuesday, 20 February 2007
Wednesday, 21 February 2007
Thursday, 22 February 2007
Friday, 23 February 2007