Oh Yeah, Developmental Biology!

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Posts tagged with "genetics"

Dinosaurs, Fruit Flies, and Us

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July 26th, 2013

There have been revolutionary advances in our knowledge of genetics in the past 30 years. This is particularly true in a field of endeavor called developmental genetics, which strives to understand how genes work to put us together. To make a baby that grows and eventually makes its own babies.

We have found that genes which coordinate development in the fruit fly are similar in structure, function, expression, and genomic organization to genes in human beings (i.e., how they are arranged on chromosomes, what regulates them and how they interact with each other). Yet fruit flies are not like us: among other obvious differences they have wings and we don’t (even if we wish we did!).

The formation of wings or legs or a segmented abdomen or hundreds of other steps are all part of a genetically specified developmental program leading to a body plan, a process which is called pattern formation. The revolution in part is the understanding of the degree of conservation of the genes responsible across huge phylogenetic chasms. In other words the degree to which the genes are the same even though we evolved into different animals almost a hundred million years ago.

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Suicidal behaviour is a disease, psychiatrists argue

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Quadruple helix' DNA discovered in human cells

In 1953, Cambridge researchers Watson and Crick published a paper describing the interweaving ‘double helix’ DNA structure - the chemical code for all life. Now, in the year of that scientific landmark’s 60th Anniversary, Cambridge researchers have published a paper proving that four-stranded ‘quadruple helix’ DNA structures - known as G-quadruplexes - also exist within the human genome. They form in regions of DNA that are rich in the building block guanine, usually abbreviated to ‘G’.

The findings mark the culmination of over 10 years investigation by scientists to show these complex structures in vivo - in living human cells - working from the hypothetical, through computational modelling to synthetic lab experiments and finally the identification in human cancer cells using fluorescent biomarkers.

Read more at: http://phys.org/news/2013-01-quadruple-helix-dna-human-cells.html#jCp

ohyeahdevelopmentalbiology:

Heterochromia (also known as a heterochromia iridis or heterochromia iridium) is an ocular condition in which one iris is a different color from the other iris (complete heterochromia), or where the part of one iris is a different color from the remainder (partial heterochromia or sectoral heterochromia). It is a result of the relative excess or lack of pigment within an iris or part of an iris, which may be inherited or acquired by disease or injury. This uncommon condition usually results due to uneven melanin content. A number of causes are responsible, including genetic, such as chimerism, Horners Syndrome and Waardenburg syndrome.

ohyeahdevelopmentalbiology:

Heterochromia (also known as a heterochromia iridis or heterochromia iridium) is an ocular condition in which one iris is a different color from the other iris (complete heterochromia), or where the part of one iris is a different color from the remainder (partial heterochromia or sectoral heterochromia). It is a result of the relative excess or lack of pigment within an iris or part of an iris, which may be inherited or acquired by disease or injury. This uncommon condition usually results due to uneven melanin content. A number of causes are responsible, including genetic, such as chimerism, Horners Syndrome and Waardenburg syndrome.


fuckyeahneuroscience:

Scientists Identify Gene Required for Nerve Regeneration | Sci-News.com
A gene that is associated with regeneration of injured nerve cells has been identified by a team of researchers led by Prof Melissa Rolls of Penn State University.
The team has found that a mutation in a single gene can entirely shut down the process by which axons – the parts of the nerve cell that are responsible for sending signals to other cells – regrow themselves after being cut or damaged.
“We are hopeful that this discovery will open the door to new research related to spinal-cord and other neurological disorders in humans,” said Prof Rolls, who co-authored a paper published online in the journal Cell Reports.
“Axons, which form long bundles extending out from nerve cells, ideally survive throughout an animal’s lifetime. To be able to survive, nerve cells need to be resilient and, in the event of injury or simple wear and tear, some can repair damage by growing new axons,” Prof Rolls explained.
Previous studies suggested that microtubules – the intracellular ‘highways’ along which basic building blocks are transported – might need to be rebuilt as an important step in this type of repair.
“In many ways this idea makes sense: in order to grow a new part of a nerve, raw materials will be needed, and the microtubule highways will need to be organized to take the new materials to the site of growth,” Prof Rolls said.
The team therefore started to investigate the role of microtubule-remodeling proteins in axon regrowth after injury. In particular, they focused on a set of proteins that sever microtubules into small pieces. Out of this set, a protein named spastin emerged as a key player in axon regeneration.
Above: In fruit flies with two normal copies of the spastin gene, a team of scientists led by Prof Melissa Rolls of Penn State University found that severed axons were able to regenerate. However, in fruit flies with two or even only one abnormal spastin gene, the severed axons were not able to regenerate (Melissa Rolls / Penn State University)

Original paper here. 

fuckyeahneuroscience:

Scientists Identify Gene Required for Nerve Regeneration | Sci-News.com

A gene that is associated with regeneration of injured nerve cells has been identified by a team of researchers led by Prof Melissa Rolls of Penn State University.

The team has found that a mutation in a single gene can entirely shut down the process by which axons – the parts of the nerve cell that are responsible for sending signals to other cells – regrow themselves after being cut or damaged.

“We are hopeful that this discovery will open the door to new research related to spinal-cord and other neurological disorders in humans,” said Prof Rolls, who co-authored a paper published online in the journal Cell Reports.

“Axons, which form long bundles extending out from nerve cells, ideally survive throughout an animal’s lifetime. To be able to survive, nerve cells need to be resilient and, in the event of injury or simple wear and tear, some can repair damage by growing new axons,” Prof Rolls explained.

Previous studies suggested that microtubules – the intracellular ‘highways’ along which basic building blocks are transported – might need to be rebuilt as an important step in this type of repair.

“In many ways this idea makes sense: in order to grow a new part of a nerve, raw materials will be needed, and the microtubule highways will need to be organized to take the new materials to the site of growth,” Prof Rolls said.

The team therefore started to investigate the role of microtubule-remodeling proteins in axon regrowth after injury. In particular, they focused on a set of proteins that sever microtubules into small pieces. Out of this set, a protein named spastin emerged as a key player in axon regeneration.

Above: In fruit flies with two normal copies of the spastin gene, a team of scientists led by Prof Melissa Rolls of Penn State University found that severed axons were able to regenerate. However, in fruit flies with two or even only one abnormal spastin gene, the severed axons were not able to regenerate (Melissa Rolls / Penn State University)

Original paper here

Hox Genes in Development: The Hox Code

Hox genes, a family of transcription factors, are major regulators of animal development. Unlike most genes, however, the order of Hox genes in the genome actually holds meaning.

The Hox genes are a set of transcription factor genes that exhibit an unusual property: They provide a glimpse of one way in which gene expression is translated into the many different forms that animals (metazoans) exhibit. For the most part, the genome seems to be a welter of various genes scattered about randomly, with no order present in their arrangement on a chromosome—the order only becomes apparent in their expression through the process of development. The Hox genes, in contrast, seem like an island of comprehensible structure. These are genes that specify segment identity—whether a segment of the embryo will form part of the head, thorax, or abdomen, for instance—and they are all clustered together in one (usually) tidy spot. Within that cluster, there is even further evidence of order.

More on Hox genes

What is Genetics?

'Are you confused by all the talk of DNA and genes? We can help. Take the tour of the basics.'

Six interactive videos that take you through some of the basic concepts in genetics. 

Move over DNA: Six new molecules can carry genes

All of a sudden, DNA has no reason to feel special. For decades it seemed that only a handful of molecules could store genetic information and pass it on. But now synthetic biologists have discovered that six others can pull off the same trick, and there may be many more to find.

The ability to copy information from one molecule to another is fundamental to all life. Organisms pass their genes to their descendants, often with small changes, and as a result life can evolve over the generations. Barring a few exceptions, all known organisms use DNA as the information carrier.

A host of alternative nucleic acids have been made in labs over the years, but no one has made them work like DNA.

This problem has now been cracked. “This unique ability of DNA and RNA to encode information can be implemented in other backbones,” says Philipp Holliger of the MRC Laboratory of Molecular Biology in Cambridge, UK.

"Everyone thought we were limited to RNA and DNA," says John Sutherlandof the MRC Laboratory of Molecular Biology in Cambridge, UK, who was not involved in the study. “This paper is a game-changer.”

Read more

Sep 9
ucsdhealthsciences:

CIRM Funds Six UC San Diego Stem Cell Researchers
The governing board of the California Institute for Regenerative Medicine (CIRM) has announced that six investigators from the University of California, San Diego Stem Cell Research program have received a total of more than $7 million in the latest round of CIRM funding. This brings UC San Diego’s total to more than $128 million in CIRM funding since the first awards in 2006.
UC San Diego scientists funded by the newly announced CIRM Basic Biology Awards IV include Maike Sander, MD, professor of Pediatrics and Cellular and Molecular Medicine; Miles Wilkinson, PhD, professor, Division of Reproductive Endocrinology; Gene Yeo, PhD, MBA, assistant professor with the Department of Cellular and Molecular Medicine and the Institute for Genomic Medicine; George L. Sen, PhD, assistant professor of cellular and molecular medicine; David Traver, PhD, associate professor with the Department of Cellular and Molecular Medicine and Ananda Goldrath, PhD, associate professor in the Division of Biological Sciences.
pictured: Human stem cells, false color.

ucsdhealthsciences:

CIRM Funds Six UC San Diego Stem Cell Researchers

The governing board of the California Institute for Regenerative Medicine (CIRM) has announced that six investigators from the University of California, San Diego Stem Cell Research program have received a total of more than $7 million in the latest round of CIRM funding. This brings UC San Diego’s total to more than $128 million in CIRM funding since the first awards in 2006.

UC San Diego scientists funded by the newly announced CIRM Basic Biology Awards IV include Maike Sander, MD, professor of Pediatrics and Cellular and Molecular Medicine; Miles Wilkinson, PhD, professor, Division of Reproductive Endocrinology; Gene Yeo, PhD, MBA, assistant professor with the Department of Cellular and Molecular Medicine and the Institute for Genomic Medicine; George L. Sen, PhD, assistant professor of cellular and molecular medicine; David Traver, PhD, associate professor with the Department of Cellular and Molecular Medicine and Ananda Goldrath, PhD, associate professor in the Division of Biological Sciences.

pictured: Human stem cells, false color.

neurosciencestuff:

Paddlefish’s doubled genome may question theories on limb evolution
The American paddlefish — known for its bizarre, protruding snout and eggs harvested for caviar — duplicated its entire genome about 42 million years ago, according to a new study published in the journal Genome Biology and Evolution. This finding may add a new twist to the way scientists study how fins evolved into limbs since the paddlefish is often used as a proxy for a more representative ancestor shared by humans and fishes.
“We found that paddlefish have had their own genome duplication,” said Karen Crow, assistant professor of biology at San Francisco State University. “This creates extra genetic material that adds complexity to comparative studies. It may change the way we interpret studies on limb development.”
In order to study how human limbs develop, scientists compare the limb-building genes found in mice with fin-building genes found in fishes. Previous research on paddlefish has suggested that fishes possessed the genetic toolkit required to grow limbs long before the evolution of the four-limbed creatures (tetrapods) that developed into reptiles, birds, amphibians and mammals.
In the last decade, paddlefish have become a useful benchmark in evolutionary studies because their position on the evolutionary tree makes them a reasonably good proxy for the ancestor of the bony fishes that evolved into tetrapods such as humans. However, the fact that paddlefish underwent a genome duplication could complicate what its genes tell us about the fin-to-limb transition, says Crow.

neurosciencestuff:

Paddlefish’s doubled genome may question theories on limb evolution

The American paddlefish — known for its bizarre, protruding snout and eggs harvested for caviar — duplicated its entire genome about 42 million years ago, according to a new study published in the journal Genome Biology and Evolution. This finding may add a new twist to the way scientists study how fins evolved into limbs since the paddlefish is often used as a proxy for a more representative ancestor shared by humans and fishes.

“We found that paddlefish have had their own genome duplication,” said Karen Crow, assistant professor of biology at San Francisco State University. “This creates extra genetic material that adds complexity to comparative studies. It may change the way we interpret studies on limb development.”

In order to study how human limbs develop, scientists compare the limb-building genes found in mice with fin-building genes found in fishes. Previous research on paddlefish has suggested that fishes possessed the genetic toolkit required to grow limbs long before the evolution of the four-limbed creatures (tetrapods) that developed into reptiles, birds, amphibians and mammals.

In the last decade, paddlefish have become a useful benchmark in evolutionary studies because their position on the evolutionary tree makes them a reasonably good proxy for the ancestor of the bony fishes that evolved into tetrapods such as humans. However, the fact that paddlefish underwent a genome duplication could complicate what its genes tell us about the fin-to-limb transition, says Crow.