Once upon a time, it was rare to meet someone who took an interest in their genealogy beyond the desire to know why people in that old family photo looked the way they did or wondered what had led up to the portrait for which they sat decades or centuries before.
For folks whose curiosity extended to fascination or perhaps obsession, finding a specialist in the genealogy field who was properly trained to ferret out lineages and the links that connect generations over time could have been dicey. Short of credentials hanging on a wall from a respected institution, finding a legitimate family tracer wasn’t like rifling through local Yellow Pages.
Then, someone came up with the brilliant idea of making it easy to conduct a genealogical search simply by ordering a boxed kit that contained instructions and swabbing materials, collecting saliva on the swab and mailing the sample back to the resource. Then came the inevitable wait for typically surprising revelations or news that could be life-altering.
How popular has DNA ancestry testing become?
Call it innate curiosity or just plain nosiness. According to MIT Technology Review, 26 million+ people had taken at-home DNA ancestry tests by February 2019.
What’s behind this growing trend besides curiosity? “Surging public interest in ancestry and health—propelled by heavy TV and online marketing,” according to reliable sources. “If the pace continues, the gene troves could hold data on the genetic makeup of more than 100 million people within 24 months,” Regalado says.
For some test takers, the mystique is grounded in finding long lost relatives or seeing where certain traits originated. Whether one submits a swab to find out whether she has a predisposition to cancer or is just curious to know why he has what he considers an irrational chocolate craving, these answers and more can find resolution when a researcher “decodes around 600,000 positions where people’s DNA code commonly differs,” adds Regalado.
The importance of DNA research
Not much of a science nerd? Perhaps this can help: “Gene expression is the process the cell uses to produce the molecule it needs by reading the genetic code written in the DNA,” explains Fabio Candotti, M.D. The cell acts like a language interpreter by translating genetic code. Each group of three letters adds one amino acid (there are 20 altogether) that do the job of building proteins.
What is genetic transcription?
Perhaps the most succinct explanation of this complicated process is that information stored on a single strand of DNA is replicated into a new molecule of what is called messenger RNA.
DNA acts like a storage center, safeguarding genetic material located within the cell nuclei. RNA may act in the same manner but RNA “is not used for long-term storage and can freely exit the nucleus.” That’s why it is not an identical copy of the DNA. Transcription takes place by an RNA enzyme that acts as glue, biding together DNA sequences. Once a copy is made, the transcription process ends.
Do you get an equal amount from your mother and father?
“Genetically, you actually carry more of your mother’s genes than your father’s.” The reason for this is that children only receive mitochondria organelles from moms. And in case you can't recall the definition of Mitochondria, here is a refresher, adds Beekman: "These are your energy-producing cell factories.” are the energy-producing factories of the cell; without them, a cell would not be able to generate energy from food.
How do DNA, RNA and mRNA differ?
While all three lay claim to being made of multiple nucleotides that form a chain (a polynucleotide), that’s where commonalities end. All three function differently. DNA, for example, contains Adenine(A), Cytosine(C), Guanine(C) and Thymine(T), while RNA has no Thymine, but it does have Uracil(U).
RNA is short and composed of single strands. Cousin DNA is double-stranded and it’s long. Compare RNA with mRNA and while they look alike, they don’t function alike. Imagine mRNA as a genetic information base carrier that resides in a cell’s DNA where it morphs into protein. If this topic engages you, you’ll want to know that there exists a fourth category: tRNA. While mRNA assumes the shape of a single line, tRNA takes the form of a clover so it’s easy to differentiate them.
More letters you should know: C, T, U and G -- plus protein
Having read the aforementioned DNA ancestry breakout, you may already have figured out what these four letters stand for: Cytosine; Thymine; Uracil and Guanine. All four are what scientists call “bases” that are found in a DNA molecule. In fact these four bases pair up to function properly, say scientists writing for Genome.gov: “Adenine pairs with thymine, and cytosine pairs with guanine.” Together, a protein is assembled that is called a gene.
According to the U.S. National Library of Medicine, since all genes contain the data required to make proteins, it’s the process that takes the longest explanation. Beginning with transcription and translation, information stored in DNA is transferred via RNA where tRNA described above is responsible for assembling a protein, making this process “one of the fundamental principles of molecular biology.”
How scientists determine ancestry and interpret those findings
Profiling has become a favorite tool of biomedical researchers because it enables them to get accurate information on the person submitting DNA. Techniques used to make determinations include DNA microarrays (measuring the activity of specific genes) and sequencing technologies (identifying all of the active genes within a cell).
The sequencing function shows investigators the cell’s potential, characteristics and even the way it is designed to function, but it won’t identify which genes within the cell are causing these traits to kick in. That’s why a gene expression profile must be undertaken, which reveals how a cell is functioning “at a specific time.” How is it behaving? Is it being influenced by either internal or external stimuli? Is it dividing? Professionals can even tell the type of environment within the host cell and learn whether it is receiving signals from other cells.
How do genes differ from chromosomes?
The word gene was coined by Danish botanist Wilhelm Johannsen in 1909 to describe the section of DNA that carries the information for a specific trait and they are the reason that we wind up with characteristics associated with our parents. Every cell in the body contains up to “thousands of genes.” Chromosomes, made up of proteins and DNA, are key players when cells divide and they ensure even copy and distribution functions, too. There are 46 chromosomes (23 pairs) in every cell.
While genes are located on chromosomes, they’re not visible, even when under microscopes, yet they are always at work inserting and deleting, processes that result in mutations. Alternately, you can see chromosomes using a microscope, perhaps because they are “the packed structure of a DNA with proteins,” notes BYJUS scientists. When chromosomes mutate, chromosomal abnormalities can result that could have far greater consequences.
Current landmark scientific discoveries in ancestry tracing
Browse the most recently completed studies to understand how diverse this subject can be.
Recent papers include the following topics, but since new postings are continually added on this website, this list remains fluid:
- A multi pronged investigation into risk factors for obesity
- MicroRNA research on the dynamics of Australian bearded dragon hibernation patterns
- Insights into the presence of Leukemia inhibitory factors in in-vitro maturation stages
- Targeted RNA expression profiling high-grade endometrial sarcoma related to uterine sarcoma
Ways we use genetic information to determine diseases or allergies
According to World Health Organization (WHO) scientists, “most diseases involve many genes in complex interactions.” Add environmental influences and people who are not born with these predispositions can still acquire diseases. “The genetic susceptibility to a particular disease due to the presence of one or more gene mutations, and/or a combination of alleles need not necessarily be abnormal,” say scientists working within WHO’s department of Noncommunicable Diseases and Mental Health (NMH).
Research studies focused on major noncommunicable diseases are currently at the forefront of clinical trials and experiments that are driving new perspectives on the treatment of cancer, cardiovascular disease and even mental health. From the use of tumor-suppressor genes to exposure to chemicals and investigating ethnic predispositions to certain illnesses (e.g., South Asians are prone to heart attacks, say WHO researchers), and with an additional spotlight on lifestyle habits that can exacerbate a predisposition, the future of diagnoses and treatment is limitless.
How do ancestry resources help uncover one’s past?
According to researchers at the Max Planck Institute Evolutionary Anthropology group, biologists and genetic engineers analyze saliva-laden swabs to read a string of letters on the DNA helix that are represented on that swab. Algorithms are applied to pull the meaning out of those letters, identifying patterns and markers that enable ancestry to be translated from that sample.
The pioneering study known as Mitochondrial Eve, set standards for analyzing saliva samples and researchers still rely upon this process to do the job. In simple terms, once the algorithm is applied, the entire genome is chopped up and compared to a vast database that reveals one’s ancestry.
Few biological processes have captured the imagination of people as profoundly as ancestry tracking, and with every submission undertaken by curious people eager to know where they came from, whether they are predisposed to be diagnosed with a serious illness or just to track down a potential family member, the net widens. Who knows what the future will bring?