Human Pangenome Map
Context:
- A pangenome reference map was created using the genomes of 47 anonymous individuals, mostly from Africa but also from the Caribbean, the Americas, East Asia, and Europe, according to a recent study that was published in the May 10 issue of the journal Nature.
Genome and genome sequencing definitions:
- The genome, which is made up of all the genes and the spaces between them that are found in each of our 23 pairs of chromosomes, is the blueprint for life.
- A continuous DNA thread makes up each chromosome.
- In other words, our genome is made up of 23 distinct strings, each of which is made up of millions of little units known as nucleotides or bases.
- All 23 of our chromosomes are made up of the four different building blocks (A, T, G, and C), which are ordered and repeated millions of times in various configurations.
- The process of genome sequencing is utilised to pinpoint the four letters’ exact placement within chromosomes.
- Understanding the genetic diversity of humans and our susceptibility to specific diseases is made possible by the sequencing of individual genomes.
- An identity card like Aadhaar is the genome. As unique as each Aadhar card is, so too is our genome.
Benchmark genome:
- Newly sequenced genomes are compared to a reference genome, which serves as a reference map. This aids in our comprehension of the locations where the recently sequenced genome and the reference genome diverge.
- The creation of the first reference genome in 2001 was one of the scientific achievements of this century. It assisted in the identification of hundreds of genes associated with numerous diseases, improved genetic understanding of conditions like cancer, and the development of new diagnostic procedures.
- Despite being a fantastic achievement, the reference genome of 2001 was only 92% complete and had several flaws. Furthermore, because it was constructed mostly from the genome of a single person with a mixed African and European background, it was not representative of all humans. Since then, all 23 human chromosomes’ entire end-to-end sequences have been added to the reference genome map, which has been updated and polished.
What is a pangenome map?
- The pangenome is a graph, in contrast to the older reference genome, which is a linear sequence.
- Each chromosome’s network resembles a stem of a bamboo, with nodes where the sequences of all 47 individuals converge and internodes of various lengths that indicate genetic variances between those individuals of various ancestries.
- In the pangenome project, the researchers used long-read DNA sequencing technologies, which result in strings of contiguous DNA strands that are tens of thousands of nucleotides long, to generate entire and contiguous chromosome maps.
- Longer reads make it possible to construct sequences with the fewest possible errors and read through repetitive chromosomal regions that were previously difficult to sequence with short-read technology.
Why Pangenome Maps are crucial:
- We can better appreciate the differences between any two people and comprehend human diversity if we have a full and error-free human pangenome map.
- It will also aid in our understanding of the genetic variations that underlie underlying medical disorders in particular groups.
- Despite the fact that the current map lacks Indian genome sequences, it will improve the mapping of Indian genomes against the error-free and comprehensive reference genomes already available.
Conclusion:
- Future pangenome maps will provide insight into disease prevalence, aid in the discovery of new genes for rare diseases, aid in the development of improved diagnostic techniques, and aid in the development of novel drugs to treat those diseases. These maps will include high quality genomes from Indians, including those from many endogamous and isolated populations within the nation.
