Category Archives: Transhuman News

March 2, 2013

Brett Smith for redOrbit.com Your Universe Online

According to a report in the journal Nature Genetics, an international team of geneticists has announced the successful sequencing of the sea lamprey genome.

The sea lamprey makes for an interesting genetic case from an evolutionary standpoint, being a jawless vertebrate that diverged from jawed vertebrates millions of years ago.

The sea lamprey is a primitive jawless vertebrate that diverged from other jawed vertebrates early in the vertebrate ancestry, said co-author David McCauley, from Oklahoma University, in a statement. Because of its early divergence from other living vertebrates, the sea lamprey genome can provide insights for understanding how vertebrate genomes have evolved, and the origins of vertebrate character traits.

McCauley explained that vertebrates have multiple copies of many genes in their genome as the result of two whole-genome rounds of genetic duplication.

One outstanding question has been the timing of these duplications in vertebrate history, he said. Results from this project suggest that two rounds of duplication predated the divergence of the ancestral lamprey from modern jawed vertebrates. This result is important for understanding how vertebrate genomes have evolved, and in particular, for understanding if the organization of the genome is common to all vertebrates.

The OU geneticist added that the lampreys unique neural physiology makes for an interesting genomic and evolutionary study.

Most vertebrates contain an insulating layer of cells that surround nerve cells, he said. Cells that wrap around a nerve fiber, or axon, are enriched in a protein known as myelin. The insulating properties of myelin allow signals to be conducted rapidly along the nerve fiber, and the loss of myelin results in numerous neurodegenerative diseases in humans.

McCauley said the neurons within lampreys are unwrapped, suggesting that the insulation is specific to jawed vertebrates.

Excerpt from:
Geneticists Complete Sea Lamprey Genome Sequencing

Public release date: 28-Feb-2013 [ | E-mail | Share ]

Contact: Angela Startz astartz@ou.edu 405-325-6664 University of Oklahoma

Beginning in 2004, a group of scientists from around the globe, including two University of Oklahoma faculty members, set out to map the genome of the sea lamprey. The secrets of how this jawless vertebrate separated from the jawed vertebrates early in the evolutionary process will give insight to the ancestry of vertebrate characters and may help investigators more fully understand neurodegenerative diseases in humans.

David McCauley, associate professor in the Biology Department in the OU College of Arts and Sciences, and Sandra W. Clifton, with the OU Center for Advanced Genome Technology, collaborated with scientists from Japan, Germany, the United States, Canada and Great Britain.

McCauley isolated and prepared the liver tissue from the single adult female sea lamprey, from which genomic DNA was isolated for sequencing. Clifton was involved in management of the sea lamprey sequencing project at the Genome Institute at Washington University in St. Louis until her retirement in 2010. The project then was taken over by Patrick Minx. Clifton participated in the discussions regarding the paper preparation, and she is a senior author on the paper. Sequencing was performed at the Genome Institute and the project was directed by Weiming Li at Michigan State University with funding provided by the National Human Genome Research Institute at the National Institutes of Health.

"The sea lamprey is a primitive jawless vertebrate that diverged from other jawed vertebrates early in the vertebrate ancestry," writes McCauley. "Because of its early divergence from other living vertebrates, the sea lamprey genome can provide insights for understanding how vertebrate genomes have evolved, and the origins of vertebrate character traits. Several important findings arise from sequencing the sea lamprey genome: Vertebrates have undergone two 'whole-genome' rounds of duplication, resulting in multiple copies of many genes present in vertebrates. One outstanding question has been the timing of these duplications in vertebrate history. Results from this project suggest that two rounds of duplication predated the divergence of the ancestral lamprey from modern jawed vertebrates. This result is important for understanding how vertebrate genomes have evolved, and in particular, for understanding if the organization of the genome is common to all vertebrates.

"Most vertebrates contain an insulating layer of cells that surround nerve cells. Cells that wrap around a nerve fiber, or axon, are enriched in a protein known as myelin. The insulating properties of myelin allow signals to be conducted rapidly along the nerve fiber, and the loss of myelin results in numerous neurodegenerative diseases in humans."

McCauley adds that lampreys lack these "wrapped" neurons, suggesting the insulated neurons are specific to jawed vertebrates. "Somewhat surprisingly, the sea lamprey genome contains multiple proteins involved in the synthesis of myelin, including its basic protein. This important finding suggests the origin of myelin predated the divergence of lampreys from the lineage leading to jawed vertebrates, but the role of these proteins in lampreys is not known. Other important findings shed light on evolution of the vertebrate adaptive immune system, and the evolution of paired appendages, such as fins in fish and fore-limbs and hind-limbs in tetrapod vertebrates such as humans and animals."

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The findings recently were published in the March issue of Nature Genetics. To read the full article, visit http://www.nature.com/ng.

See the original post:
Sea lamprey genome mapped with help from scientists at OU

Feb. 28, 2013 Beginning in 2004, a group of scientists from around the globe, including two University of Oklahoma faculty members, set out to map the genome of the sea lamprey. The secrets of how this jawless vertebrate separated from the jawed vertebrates early in the evolutionary process will give insight to the ancestry of vertebrate characters and may help investigators more fully understand neurodegenerative diseases in humans.

David McCauley, associate professor in the Biology Department in the OU College of Arts and Sciences, and Sandra W. Clifton, with the OU Center for Advanced Genome Technology, collaborated with scientists from Japan, Germany, the United States, Canada and Great Britain.

McCauley isolated and prepared the liver tissue from the single adult female sea lamprey, from which genomic DNA was isolated for sequencing. Clifton was involved in management of the sea lamprey sequencing project at the Genome Institute at Washington University in St. Louis until her retirement in 2010. The project then was taken over by Patrick Minx. Clifton participated in the discussions regarding the paper preparation, and she is a senior author on the paper. Sequencing was performed at the Genome Institute and the project was directed by Weiming Li at Michigan State University with funding provided by the National Human Genome Research Institute at the National Institutes of Health.

"The sea lamprey is a primitive jawless vertebrate that diverged from other jawed vertebrates early in the vertebrate ancestry," writes McCauley. "Because of its early divergence from other living vertebrates, the sea lamprey genome can provide insights for understanding how vertebrate genomes have evolved, and the origins of vertebrate character traits. Several important findings arise from sequencing the sea lamprey genome: Vertebrates have undergone two 'whole-genome' rounds of duplication, resulting in multiple copies of many genes present in vertebrates. One outstanding question has been the timing of these duplications in vertebrate history. Results from this project suggest that two rounds of duplication predated the divergence of the ancestral lamprey from modern jawed vertebrates. This result is important for understanding how vertebrate genomes have evolved, and in particular, for understanding if the organization of the genome is common to all vertebrates.

"Most vertebrates contain an insulating layer of cells that surround nerve cells. Cells that wrap around a nerve fiber, or axon, are enriched in a protein known as myelin. The insulating properties of myelin allow signals to be conducted rapidly along the nerve fiber, and the loss of myelin results in numerous neurodegenerative diseases in humans."

McCauley adds that lampreys lack these "wrapped" neurons, suggesting the insulated neurons are specific to jawed vertebrates. "Somewhat surprisingly, the sea lamprey genome contains multiple proteins involved in the synthesis of myelin, including its basic protein. This important finding suggests the origin of myelin predated the divergence of lampreys from the lineage leading to jawed vertebrates, but the role of these proteins in lampreys is not known. Other important findings shed light on evolution of the vertebrate adaptive immune system, and the evolution of paired appendages, such as fins in fish and fore-limbs and hind-limbs in tetrapod vertebrates such as humans and animals."

The findings recently were published in the March issue of Nature Genetics.

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Sea lamprey genome mapped

The human genome can generate molecular hoops similar in makeup to DNA that could potently interfere with genetic activity, researchers say.

These findings reveal there are secrets within the genomes of humans and other animals that scientists are still uncovering, and the old belief that life has useless junk DNA is more false than ever, scientists added.

Discovering more about circular versions of RNA (a molecule similar to DNA that can carry genetic information) could also lead to new ways of fighting diseases such as diabetes, brain tumors and Parkinson's disease, investigators added.

The human genome the blueprint for human life is made of DNA. From the genome, intermediate molecules known as RNA are created that help manufacture key biomolecules such as proteins, which then carry out cellular processes.

After international teams of researchers completely sequenced the human genome, they found about 95 percent of it unexpectedly did not code for proteins. Since this noncoding DNA initially seemed to have no known biological function, some scientists referred to it as junk DNA. [Unraveling the Human Genome: 6 Molecular Milestones]

However, over time, researchers have discovered this noncoding DNA can serve a wide variety of vital purposes. For instance, noncoding DNA can give rise to snippets of RNA known as micro-RNA that can suppress the so-called messenger RNA that normally helps manufacture proteins. This micro-RNA serves a key role in controlling genetic activity, and scientists are developing therapies based on micro-RNA to dampen harmful, malfunctioning genes.

Now researchers find the genomes of humans and other animals can generate circular RNA, highly stable rings that can sponge up micro-RNA, apparently keeping them from interfering with genetic activity if necessary.

"There seems to be a whole new layer of gene regulation," researcher Jrgen Kjems, a molecular biologist at Aarhus University in Denmark, told LiveScience.

For instance, Kjems and his colleagues found high levels of a circular RNA they dubbed ciRS-7 in the human and mouse brain. This molecule potently suppresses a micro-RNA named miR-7, which is found in everything from worms to humans. They also found a circular RNA known as Sry that is specific to testicles and targets a micro-RNA known as miR-138, suggesting that circular RNA might play a role in sex development.

In addition, when Nikolaus Rajewsky at the Max Delbrck Center for Molecular Medicine in Berlin and his colleagues analyzed human, mouse and nematode worm RNA, they detected thousands of circular RNAs. These were often linked with specific tissues or developmental stages.

Read the original here:
Weird Molecular Hoops Made From Human Genome