What is the human genome? This is a detailed plan for the development of the body. It contains information on protein coding. Imagine that a DNA molecule is one big test of protein tests or genes. But, surprisingly, there are only 28 thousand such genes, which is 1% of the total DNA test. Naturally, along with protein tests, various RNAs are also encoded. But they have nothing to do with proteins, such as tRNA or rRNA.
There are also sites that play a regulatory role. They turn various genes on and off as needed. But again, for these purposes, an insignificant share of the total test is required - about another 1%.
So what is the remaining 98% of DNA doing? These days it is thought to be trash. In other words, junk DNA. All this rubbish has accumulated over the course of evolution. That is, it did not affect the size of the molecule in any way, since it had more important tasks. But the simplest is a completely different matter. They have no rubbish.
However, there is another opinion. Those who adhere to it believe that science still has a very poor idea of how the genome works. Therefore, it classifies as rubbish everything that cannot be used. The more we know about the genome, the less unnecessary garbage will remain in it, of which there is now a huge amount.
One of the most interesting things to do is comparing different genomes. There is even a related field called bioinformatics. She studies the sets of genes in humans, their distant ancestors, as well as in other living organisms that inhabit the planet. However, the sets of genes in different species and subspecies differ very little. So what makes a person “the crown of nature”? Most likely, regulatory sites, as well as point mutations in genes.
But if everything is so monotonous for absolutely different creatures, then what can we say about the individual differences between people. These differences are in point substitutions of nucleotides. They are called snips. They are scattered unevenly throughout the genome and do not lead to changes in protein sequences. We will not go into the jungle, but only say that strictly individually these SNPs are expressed in hypervariable regions of DNA. They are as unique to each person as fingerprints.
So we come to the most important thing. Since the 1980s, the human genome has provided invaluable assistance to criminologists in solving a crime. It was at this time that such a term as "DNA analysis" appeared. At first, it was carried out only in solving rape crimes. After all, criminals left a large amount of sperm. But science went forward, and in the 21st century, the possibilities of DNA diagnostics increased significantly.
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Now it is enough to find a drop of blood or saliva, a hair, a microscopic particle of skin at the crime scene - and this will be quite enough. So we can safely talk about a revolution in forensics. Let's remember fingerprinting. She greatly facilitated the investigation. Now it has become even easier. Thanks to progressive diagnostic methods, the innocent convicts were released. At least this state of affairs is observed everywhere in the United States.
DNA analysis is also good in that it allows you to establish the identity of long-dead people from whom there are no DNA samples left. In this case, an analysis is done with close relatives. The thing is that the sequences of hypervariable regions in relatives are very similar. If genomic DNA does not help, then mitochondrial DNA is the final verdict. That is, the error is completely eliminated.
DNA analysis.
In the United States and Great Britain, a project to create a computerized database containing DNA markers of all persons who have committed serious crimes is nearing completion. In other words, there used to be a fingerprint filing cabinet, and now a global database with markers. To obtain such a marker, it is enough to take saliva for analysis.
And a specific example. In 2003, Lacey Peterson, who lived on the outskirts of San Francisco, disappeared in the United States for Christmas. She was 8 months pregnant, and her husband, Scott, claimed that while he was fishing, his wife had been kidnapped. There was no trace, and the police were forced to stop searching.
But after 4 months, the bodies of a woman and a baby, decapitated and badly damaged by fish, were found on the ocean shore. They were no longer even bodies, but skeletons. It took only 2 days to establish that they belonged to Lacey and her unborn son. Scott was detained while crossing the Mexican border. The point was that during the investigation, Scott indicated his fishing spot half a mile from the stretch of coast where the human remains were found. If there was no DNA analysis, then there would be no way to identify the bodies.
However, one should not forget that while such analyzes are very expensive. Therefore, in order to determine the human genome with a complete nucleotide sequence, you need to shell out a tidy sum. Today in the world there are complete genomes of only 2 inhabitants of the planet. This is Jim Watson and Craig Venter. They were engaged in a genomic project and decided to decipher their own DNA tests.
But forensic science is only part of the opportunities that open before humanity. Having on hand the entire genetic chain of a particular person, one can get an idea of his hereditary diseases. Therefore, it will be possible to prevent some serious diseases. And if the genes are adjusted, then in this case a person will be able to get rid of many health problems. But all this is a matter of the future and, most likely, not so distant.