Skip to comments.Scientists Analyze Chromosomes 2 and 4: Discover Largest "Gene Deserts"
Posted on 04/13/2005 6:20:23 PM PDT by PatrickHenry
A detailed analysis of chromosomes 2 and 4 has detected the largest "gene deserts" known in the human genome and uncovered more evidence that human chromosome 2 arose from the fusion of two ancestral ape chromosomes, researchers supported by the National Human Genome Research Institute (NHGRI), part of the National Institutes of Health (NIH), reported today.
In a study published in the April 7 issue of the journal Nature, a multi-institution team, led by [load of names deleted, but available in the original article].
"This analysis is an impressive achievement that will deepen our understanding of the human genome and speed the discovery of genes related to human health and disease. In addition, these findings provide exciting new insights into the structure and evolution of mammalian genomes," said Francis S. Collins, M.D., Ph.D., director of NHGRI, which led the U.S. component of the Human Genome Project along with the DOE.
Chromosome 4 has long been of interest to the medical community because it holds the gene for Huntington's disease, polycystic kidney disease, a form of muscular dystrophy and a variety of other inherited disorders. Chromosome 2 is noteworthy for being the second largest human chromosome, trailing only chromosome 1 in size. It is also home to the gene with the longest known, protein-coding sequence - a 280,000 base pair gene that codes for a muscle protein, called titin, which is 33,000 amino acids long.
One of the central goals of the effort to analyze the human genome is the identification of all genes, which are generally defined as stretches of DNA that code for particular proteins. The new analysis confirmed the existence of 1,346 protein-coding genes on chromosome 2 and 796 protein-coding genes on chromosome 4.
As part of their examination of chromosome 4, the researchers found what are believed to be the largest "gene deserts" yet discovered in the human genome sequence. These regions of the genome are called gene deserts because they are devoid of any protein-coding genes. However, researchers suspect such regions are important to human biology because they have been conserved throughout the evolution of mammals and birds, and work is now underway to figure out their exact functions.
Humans have 23 pairs of chromosomes - one less pair than chimpanzees, gorillas, orangutans and other great apes. For more than two decades, researchers have thought human chromosome 2 was produced as the result of the fusion of two mid-sized ape chromosomes and a Seattle group located the fusion site in 2002.
In the latest analysis, researchers searched the chromosome's DNA sequence for the relics of the center (centromere) of the ape chromosome that was inactivated upon fusion with the other ape chromosome. They subsequently identified a 36,000 base pair stretch of DNA sequence that likely marks the precise location of the inactived centromere. That tract is characterized by a type of DNA duplication, known as alpha satellite repeats, that is a hallmark of centromeres. In addition, the tract is flanked by an unusual abundance of another type of DNA duplication, called a segmental duplication.
"These data raise the possibility of a new tool for studying genome evolution. We may be able to find other chromosomes that have disappeared over the course of time by searching other mammals' DNA for similar patterns of duplication," said Richard K. Wilson, Ph.D., director of the Washington University School of Medicine's Genome Sequencing Center and senior author of the study.
In another intriguing finding, the researchers identified a messenger RNA (mRNA) transcript from a gene on chromosome 2 that possibly may produce a protein unique to humans and chimps. Scientists have tentative evidence that the gene may be used to make a protein in the brain and the testes. The team also identified "hypervariable" regions in which genes contain variations that may lead to the production of altered proteins unique to humans. The functions of the altered proteins are not known, and researchers emphasized that their findings still require "cautious evaluation."
In October 2004, the International Human Genome Sequencing Consortium published its scientific description of the finished human genome sequence in Nature. Detailed annotations and analyses have already been published for chromosomes 5, 6, 7, 9, 10, 13, 14, 16, 19, 20, 21, 22, X and Y. Publications describing the remaining chromosomes are forthcoming.
The sequence of chromosomes 2 and 4, as well as the rest of the human genome sequence, can be accessed through the following public databases: GenBank (www.ncbi.nih.gov/Genbank) at NIH's National Center for Biotechnology Information (NCBI); the UCSC Genome Browser (www.genome.ucsc.edu) at the University of California at Santa Cruz; the Ensembl Genome Browser (www.ensembl.org) at the Wellcome Trust Sanger Institute and the EMBL-European Bioinformatics Institute; the DNA Data Bank of Japan (www.ddbj.nig.ac.jp); and EMBL-Bank (www.ebi.ac.uk/embl/index.html) at EMBL's Nucleotide Sequence Database. [Links in original article.]
NHGRI is one of the 27 institutes and centers at NIH, an agency of the Department of Health and Human Services. The NHGRI Division of Extramural Research supports grants for research and for training and career development at sites nationwide. Additional information about NHGRI can be found at www.genome.gov.
What happened to, Everybody be nice.?
If we evolved from apes why are there still apes?
Blind from what? What's to gain from believing that I evolved from an ape? The only thing this "science" does is confuse people about their faith. Thats it. Am I going to go ask an ape for reparations... What? you tell me... Pretty idiotic to believe in nonsense, whose sole purpose is to undermine the church in the first place.
Read this especially the things about the Church and family
Clearly He did so, but the mechanism of reuse is what's in contention.
Now now, Ahban. No need to resort to lies. You're better than that.
Thanks for the ping!
<sigh> that's fer shure.
The immune system includes organs and tissues in which lymphocytes predominate as well as cells that circulate in peripheral blood. Lymphoid organs includes: lymph nodes and vessels, spleen, tonsils, adenoids, appendix, bone marrow, thymus, and intestinal lymphoid tissue. The bone marrow and thymus play a role in developing the primary cells of the immune system: B cells and T cells.
If America was once part of England why is there still an England?
Clearly your complete and total inability to grasp scientific evidence is on display for all to see.
I am sure you see electricity as magic and that when lightning strikes it is "God is Angry."
How you reconcile wireless connections is beyond me but I suspect it is something like "invisible angels move bits from place to place." I guess you pray to these invisible angels to keep your radio and TV connections going daily.
I am sure toilet flushing is beyond your ability to reckon. Just write it up to more magic.
Because it was part of England.
Wonder what a tarsier looks like?Tarsiers are really cute, in their way. But they sorta look like what that mouse/human chimera would look like if they took that experiment too far!
The only thing this "science" does is confuse people about their faith.
Ah... So you're going to turn your computer back in and communicate via smoke signals?
Or the average corporate or governmental middle manager. Although the way I've most often heard their behavior described was as a P**ing contest, to see who could reach higher on the wall, and thus earn the favor of the Alpha above them. :)
We must first determine what we are talking about when we use the terms "Science" and "Evolution"
I. Science. According to the Oxford Dictionary science is "A branch of study which is concerned either with a connected body of demonstrated truths or with observed facts systematically classified and more or less colligated by being brought under general laws, and which includes trustworthy methods for the discovery of new truth within its own domain."
For a postulate to qualify as a scientific theory is must fulfill three basic criteria.
1. The postulate must be observable.
2. The postulate must be capable of repeatable experimental verification.
3. The postulate must withstand a falsifiability test, or an experiment must be conceived the failure of which would disprove the postulate.
Neither evolution nor creation can meet the above three criteria and thus are not theories but postulates. In fact neither are fully capable of becoming theories because of the limits of observing events that happened many years in the past.
Which translation? They don't all agree in every detail and nuance.