Human genome sequencing was a seismic event in life sciences history when researchers released the first set of human genome sequences in February 2001. However, only 15 percent of the genome had been deciphered, and the research was not complete. Molecular complexity and technological advancement were required for the most complex part of DNA.
Almost two decades later, scientists have finally deciphered all of it, resolving a long list of errors in previous versions of human DNA and fundamentally changing the way we view it. Approximately 115 new genes of protein coding were identified as part of this groundbreaking discovery by 99 researchers.
An international consortium which includes around 30 institutions called the Telomere-to-Telomere (T2T) Consortium has released data revealing how DNA affects disease risks and the way cells keep it organized using telomeres. DNA holds essential information that had remained elusive for a long time, says scientists. These details will reveal all.
Human genome: What is it?
The genome is the set of instructions that determine how an organism develops and how it directs its activities (DNA). Their structure is a twisting, paired strand with two twists in parallel, also called a double helix. A DNA strand contains four chemical units called nucleotide bases that make up the genetic “alphabet,” according to the National Human Genome Research Institute.
The human genome, or DNA base pair, is made up of approximately 3 billion base pairs, or letters, within every single cell in the body. An entire body is made up of four letters – the language of DNA.
Why did deciphering the human genome take so long?
Our DNA code contains 3,055 billion base pairs (“letters”), as revealed by scientists. Although the first draft of the document was released in 2001, the wait was two decades long. Genes spread over 23 pairs of chromosomes has been known for decades. The structure of these creatures has remained a mystery, however. Toward the end of the 20th century, researchers began working on deciphering these mysterious structures.
The genome is largely composed of viruses-like segments of DNA that make new copies of themselves, rather than genes. Using an algorithm that decodes the sequences of each fragment of their genome, they pieced them back together again.
Nevertheless, when researchers worked on figuring these structures out, they found that our cells have approximately three billion letters on each twin strand of DNA. Assembling the DNA puzzle turned out to be more difficult than they anticipated.
Millions of bases were unable to be placed because long stretches of the genome were unknown. Their initial draft was released in 2001, however they released the revised draft of the reference genome in 2013, which described a more accurate read of these fragments.
Adam Phillippy tells The New York Times that he was “puzzled in a way by the missing pieces” of the Telomere-to-Telomere Consortium. “Let me just say that to a perfectionist, that’s quite bothersome.”
Human Genome Project – what is it?
Three major methods were employed to decipher the human genome by the Human Genome Project that was realised in 1988:
Our genome’s DNA sequence is determined by the order in which all the bases appear
The process of making maps showing all major sections of chromosomes on which genes are located
Linkage maps are produced through which inherited traits are inherited
There are probably around 20,500 genes in the human genome, and information about their structure, organization, and function can be considered the most fundamental instruction set for the development and function of an individual.
First draft findings of this report revealed a startling lack of genes, compared to previous estimates of between 50,000 and 1,40,000 genes.
As Francis Collins said in 2001, “it is a history book of evolution of our species through time. It is a manual on how to build every cell in a human body and it is a groundbreaking textbook featuring insights that will give health care providers new ways to treat and prevent disease.”