Human Genome Project:
The project started off in the early 1980's supported by the Department of Energy in workshops in '84 and '86. A scientist named James D. Watson was head of the National Center for the Human Genome Research at the NIH (National Institue of Health) in the US starting around '88. His boss, Bernadine Healy, and Watson disagreed over the issue of patenting genes and Watson was forced to resgin in '92, he was soon replaced by Francis Collins in April '93. The 3-billion project was funded formally in 1990 by teh Department of Engery and the National Institutes of Health. It was expected to take 15 years to complete.
-First, the central regions of each chromosome, known as centromeres, are highly repetitive DNA sequences that are difficult to sequence using current technology. The centromeres are millions (possibly tens of millions) of base pairs long, and for the most part these are entirely un-sequenced.
-Second, the ends of the chromosomes, called telomeres, are also highly repetitive, and for most of the 46 chromosome ends these too are incomplete. It is not known precisely how much sequence remains before the telomeres of each chromosome are reached, but as with the centromeres, current technological restraints are prohibitive.
-Third, there are several loci in each individual's genome that contain members of multigene families that are difficult to disentangle with shotgun sequencing methods - these multigene families often encode proteins important for immune functions.
Other than these regions, there remain a few dozen gaps scattered around the genome, some of them rather large, but there is hope that all these will be closed in the next couple of years.
Other than these regions, there remain a few dozen gaps scattered around the genome, some of them rather large, but there is hope that all these will be closed in the next couple of years.
In summary: the best estimates of total genome size indicate that about 92.3% of the genome has been completed [2] and it is likely that the centromeres and telomeres will remain un-sequenced until new technology is developed that facilitates their sequencing. Most of the remaining DNA is highly repetitive and unlikely to contain genes, but it cannot be truly known until it is entirely sequenced. Understanding the functions of all the genes and their regulation is far from complete. The roles of junk DNA, the evolution of the genome, the differences between individuals, and many other questions are still the subject of intense interest by laboratories all over the world.
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