Wissenschaft und Deutsch (on Hiatus)

What Are The Odds? – Kermode Bear

The Spirit Bear is actually a white Black Bear, which sounds funny and incredibly contradictory but it is the truth. They are not albino and as such don’t have the pink eyes that is normally associated with albino animals, rather the colour of their fur is a result of two recessive genes being expressed. It is believed that 1 out of 10 Black Bears carry this recessive “white-coat” gene, so in theory, they should be able to exist anywhere that Black Bears live. Interestingly enough, the main population of Kermode Bears can be found on the islands off the coast of British Columbia, Canada in a temperate rainforest appropriately named the Great Bear Rainforest. The population of Spirit Bears is most likely greatest in this area as a result of conservation efforts of the First Nation tribes. These groups valued the Kermode Bear and as such didn’t hunt or trap this beautiful creature. As a result it is believed that the population of the Spirit Bear is between 400-1000 individuals in this area. How is that for proof that animal conservation can truly help a species (or sub-species) survive.

source for above text

I really dislike the way this and most articles are written about the Kermode Bear so I am also going to link in the well known Nat Geo article for a full understanding.

ANATOMY OF OUR GENES: The Human Body

The human body is made of some 50 trillion to 100 trillion cells, which form the basic units of life and combine to form more complex tissues and organs. Inside each cell, genes make up a “blueprint” for protein production that determines how the cell will function. Genes also determine physical characteristics or traits. The complete set of some 20,000 to 25,000 genes is called the genome. Only a tiny fraction of the total genome sets the human body apart from those of other animals.

Most cells have a similar basic structure. An outer layer, called the cell membrane, contains fluid called cytoplasm. Within the cytoplasm are many different specialized “little organs” called organelles. The most important of these is the nucleus, which controls the cell and houses the genetic material in structures called chromosomes. Another type of organelle is mitochondrion. These “cellular power plants” have their own genome and do not recombine during reproduction.

Chromosomes

Chromosomes carry hereditary, genetic information in long strings of DNA called genes. Humans have 22 numbered pairs of chromosomes and a single pair of sex chromosomes—XX in females and XY in males. Each chromosomal pair includes one inherited from the father and one from the mother. If unwound, the microscopic DNA strands in one cell’s nucleus would stretch to over six feet (two meters) in length.

DNA

DNA (deoxyribonucleic acid) is the set of genetic instructions for creating an organism. DNA molecules are shaped like a spiral staircase called a double helix. Each stair is composed of the DNA bases A, C, T, and G. Some segments of these bases contain sequences, like A-T-C-C-G-A-A-C-T-A-G, which constitute individual genes. Genes determine which proteins individual cells will manufacture, and thus what function particular cells will perform. 

read more, photos and info from Nat Geo

Albinism is a genetic condition also called achromia, achromasia, or achromatosis. It is characterized by a deficit in the production in melanin and by the partial or complete absence of pigment in the skin, hair and eyes. This hereditary disease can be found in humans (affecting all races), mammals, birds, fish, reptiles and amphibians. 

Even though it is a hereditary condition, in most cases, there’s no family history of albinism.

People with albinism often have vision problems and are susceptible to sunburns and skin cancers if they do not protect themselves from direct sunlight. 

According to The National Organization for Albinism and Hypopigmentation, one in every 17,000 people in the United States has some type of albinism.

What are the signs and symptoms of albinism?

Since birth, people with albinism have little or no pigmentation in their eyes, skin and hair (oculocutaneous albinism) or sometimes in the eyes alone (ocular albinism). 


The degree of pigmentation varies. Some people gain a little pigmentation in their hair or eyes with age. Some develop pigmented freckles on their skin. An individual with complete absence of melanin is called an albino. One with only a small amount of melanin is described as albinoid.

People with albinism are very pale with fair hair and very light eyes. In some people, the eyes appear red or purple, depending on the amount of pigment. This can happen because the iris actually has very little color. The eyes appear pink or red because the blood vessels inside of the eye show through the iris. 

A person with albinism is generally as healthy as the rest of the population. However, problems with vision and skin are particularly common. 

Vision Problems. Vision problems in albinism result from abnormal development of the retina and abnormal patterns of nerve connections between the eye and the brain. Most people with albinism have problems with their eyesight; many have low vision. Lack of pigment in the eyes results in problems with eyesight, both related and unrelated to photosensitivity. This sensitivity generally leads to discomfort in bright light. 

Skin problems. The dark pigment - melanin - helps protect the skin from the sun’s ultraviolet radiation. People with albinism lack this pigment; their skin can burn more easily from overexposure. They need to take precautions to avoid damage to the skin caused by the sun; this means applying sunscreen lotions, and wearing hats and sun-protective clothing.

read more

photos of animals from Nat Geo

photos of people from Gustavo Lacerda’s photo project on Albinism  


Big Pic: A Fruit Fly Born In Outer Space


Something seems a little off here…

By 


Francie Diep


This is a fruit fly, raised in space. Space was not directly what made it furred all over with white, but indirectly it was. The white stuff is fungus, and the fly grew it because after hatching and growing to adulthood in space, it didn’t fight off a fungal infection the way a healthy fly that had grown up on Earth would.
The image comes from the research of a team of biologists from several U.S. institutions. Observations of astronauts and studies done in human immune cells have shown that space weakens the immune system. This U.S. team wanted to learn more about what was happening at a cellular level. Their little spacefaring flies taught them that low gravity shuts off an important component of the fly immune system—one that has a human counterpart.  
Their findings gave them some starting ideas about why people also have compromised immunity after spending time in space, they wrote in a paper they published today in the journal PLOS ONE. One experiment they performed in hypergravity—created for the flies using a centrifuge in a lab on Earth—also suggested exposure to gravity could prevent the immune effects of space.
The team sent fruit fly eggs to space aboard the space shuttle Discovery. (Fun fact: These were the first flies to go into space in the name of immunology.) The eggs spent 12 days in space, during which time they hatched, crawled around a bit as larva, and became adult flies. Then they came back down to Earth, where biologists infected them with one of two things, either E. colibacteria or a fungus called Beauveria bassiana. (I survived space and all I got was a fungal infection.)
The space flies’ immune system fought off the E. coli, but not the Beauveria bassiana fungus. Meanwhile, similar control flies raised on Earth fought off both infections.
To figure out why the space flies had trouble with the fungus, the scientists analyzed all of the flies’ genes. Both the space flies and the Earth flies were born with the same genes, but exactly which of those genes turned on and went to work differed between them. In Earth flies, the genes associated with their immune systems kicked into high gear after they got infected with the fungus. Among other genes, Earth flies activated something called the Toll signaling pathway, which scientists have long known flies use to fight off fungi. Humans have Toll-like genes, too, and they also work in immunity.
The space flies reacted differently from their stay-at-home siblings. They turned on some immunity genes after encountering Beauveria bassiana, so it’s not like they were totally helpless. But they didn’t use all of the genes the Earth flies used, and they didn’t turn up their Toll pathway genes. In their paper, the biologists called their spacefaring flies “severely immunocompromised.”
Strangely, when the biologists raised flies in a centrifuge to simulate higher-than-Earth gravity, they were more likely to survive a fungal infection than normal Earth flies.
The science team offered some hypotheses about what could be happening that would alter what genes flies activate, depending on the gravity they’re exposed to. The hypotheses are testable, the team noted, although the team didn’t do that for this paper. The next step should be to send fruit flies to the International Space Station, the biologists wrote, where the little bugs can spend longer in space.
from Popsci

Big Pic: A Fruit Fly Born In Outer Space

Something seems a little off here…




The gene, Lin28a, is being dubbed the “Wolverine” or “Fountain of Youth” gene. It’s usually only produced in developing embryos, but when switched on in adult mice it causes them to grow hair faster and repair bone, cartilage, skin and other soft tissues almost completely. Lin28a works by boosting metabolism in mitochondria, a discovery that could lead to regenerative treatments in humans.
Read more: http://bit.ly/1c2M1xy via Nature. Image: 20TH CENTURY FOX/REX FEATURES

source
The gene, Lin28a, is being dubbed the “Wolverine” or “Fountain of Youth” gene. It’s usually only produced in developing embryos, but when switched on in adult mice it causes them to grow hair faster and repair bone, cartilage, skin and other soft tissues almost completely. Lin28a works by boosting metabolism in mitochondria, a discovery that could lead to regenerative treatments in humans.

Read more: http://bit.ly/1c2M1xy via Nature. Image: 20TH CENTURY FOX/REX FEATURES

Aniridia is a genetic condition that affects people at birth. The term “aniridia” literally means “without iris” (the colored part of the eye), which is generally the first indication that an individual has aniridia.  A person who has aniridia is born without a fully developed iris. The name ‘aniridia’ is somewhat misleading because aniridia is a panocular condition, meaning it usually affects other components of the anatomy of the eye in addition to the iris.

Actually, the lack of the iris is the least of the ocular problems associated with aniridia. Aniridia can affect the entire anatomy – the cornea, the fovea or retina, as well as the lens.  As a result, ocular conditions can include glaucoma, foveal hypoplasia, nystagmus, strabismus, dry eye, corneal degeneration, and cataracts. Most people with aniridia have at least one of these associated ocular conditions that impact their vision.

Aniridia is a rare eye condition, affecting approximately 1 in 60,000 births.  However, the ocular problems associated with aniridia mentioned above are quite common.  What is rare is to have all of these conditions present in one individual.

Although people with aniridia always have vision problems, the degree varies greatly and is dependent upon which complications, in addition to the lack of iris, an individual has.  Generally, individuals with aniridia have a visual acuity measurement between 20/80 and 20/200.  Some are legally blind, while others have vision good enough to drive a car.  Most individuals with aniridia read without using Braille, especially in today’s technically advanced environment of e-Readers.

It is important to note that some of the conditions related to aniridia are non-degenerative (meaning they do not get worse over time) and others are degenerative.  Conditions that can degenerate the vision of an individual with aniridia include corneal keratopathy, glaucoma, and cataracts.  For more information on these conditions and treatments, please refer to the menu on the right ‘Aniridia’s Impact on Vision’ under the ‘Learn More’ heading.

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Three-Way Parenthood
Avoiding the transmission of mitochondrial disease takes a trio, but raises a host of logistical issues.
When first used in humans in the 1970s, in-vitro fertilization (IVF) raised significant ethical, legal, and philosophical concerns. The ability to manipulate human reproduction was viewed in many circles as an attack on the traditional family and an odious attempt to assert human dominion over nature. Terms such as “designer babies” and “playing God” were commonly applied to IVF. Nevertheless, much of the scientific community touted the potential benefits of these technologies, viewing them as the start of a new era of medicine. Indeed, despite those dire predictions four decades ago, IVF is now widely accepted and has enabled infertile couples to conceive more than 5 million healthy babies.
Fourteen years ago, my Columbia University colleagues and I (JL) examined the mitochondrial origins of Dolly, the cloned sheep, and proposed the concept of a “three-parent” fertility procedure to treat mitochondrial disorders (Nat Genet, 23:90-93, 1999). The unique genetic information within mitochondria enables these organelles to function as the biochemical engines of the cell. However, sometimes deleterious mutations occur in mitochondrial DNA (mtDNA) that cause myriad human pathologies—such as heart problems, liver failure, brain disorders, blindness, hearing loss, myopathy, and in the most extreme cases, death. These mitochondrial disorders are incurable and are passed down maternally from generation to generation. One in 6,500 children worldwide is affected with mtDNA defects. (See “Power Failure,” The Scientist, May 2011.)
To prevent defective mtDNA from being passed from mother to child, scientists in the U.K. are planning to offer a “three-parent” fertility procedure. Based in part on protocols developed by scientists at the New York Stem Cell Foundation and at Columbia University Medical Center (Nature, 493:632-39, 2013), this procedure modifies standard IVF technology to create an embryo from the eggs of two women and sperm obtained from one man. Specifically, nuclear DNA from the egg of a woman carrying mitochondrial defects is transferred into the enucleated cytoplasm of a donor egg that harbors nonmutated mtDNA. This genetically reconstituted egg is then fertilized in vitro by sperm from a male partner, and the resulting embryo is implanted into the uterus of the woman with the mitochondrial disorder. This embryo will contain genetic material from three donors, but will not express any symptoms of the mitochondrial disorder.
The potential for creating children from multiple parents is not limited to the halting of the passage of mitochondrial disorders. In May 2013, Shoukhrat Mitalipov and his colleagues at the Oregon Health and Science University published a milestone article describing the use of IVF technology to transfer genetic material from any nonsperm cell into a human egg, thereby generating a pre-implantation embryo from which human embryonic stem cells can be readily isolated and maintained in the laboratory (Cell, 153:1228-38, 2013). One of many potential outcomes of this research is the ability to create a human embryo without any male genetic contribution—by transferring the nucleus of a somatic cell from one woman into an enucleated egg of another. Embryos could also be made from more than three genetic parents by merging multiple embryos into a single chimeric infant, as has already been achieved in rhesus monkeys (Cell, 148:285-95, 2012).
read more 

Three-Way Parenthood

Avoiding the transmission of mitochondrial disease takes a trio, but raises a host of logistical issues.

When first used in humans in the 1970s, in-vitro fertilization (IVF) raised significant ethical, legal, and philosophical concerns. The ability to manipulate human reproduction was viewed in many circles as an attack on the traditional family and an odious attempt to assert human dominion over nature. Terms such as “designer babies” and “playing God” were commonly applied to IVF. Nevertheless, much of the scientific community touted the potential benefits of these technologies, viewing them as the start of a new era of medicine. Indeed, despite those dire predictions four decades ago, IVF is now widely accepted and has enabled infertile couples to conceive more than 5 million healthy babies.

Fourteen years ago, my Columbia University colleagues and I (JL) examined the mitochondrial origins of Dolly, the cloned sheep, and proposed the concept of a “three-parent” fertility procedure to treat mitochondrial disorders (Nat Genet, 23:90-93, 1999). The unique genetic information within mitochondria enables these organelles to function as the biochemical engines of the cell. However, sometimes deleterious mutations occur in mitochondrial DNA (mtDNA) that cause myriad human pathologies—such as heart problems, liver failure, brain disorders, blindness, hearing loss, myopathy, and in the most extreme cases, death. These mitochondrial disorders are incurable and are passed down maternally from generation to generation. One in 6,500 children worldwide is affected with mtDNA defects. (See “Power Failure,” The Scientist, May 2011.)

To prevent defective mtDNA from being passed from mother to child, scientists in the U.K. are planning to offer a “three-parent” fertility procedure. Based in part on protocols developed by scientists at the New York Stem Cell Foundation and at Columbia University Medical Center (Nature, 493:632-39, 2013), this procedure modifies standard IVF technology to create an embryo from the eggs of two women and sperm obtained from one man. Specifically, nuclear DNA from the egg of a woman carrying mitochondrial defects is transferred into the enucleated cytoplasm of a donor egg that harbors nonmutated mtDNA. This genetically reconstituted egg is then fertilized in vitro by sperm from a male partner, and the resulting embryo is implanted into the uterus of the woman with the mitochondrial disorder. This embryo will contain genetic material from three donors, but will not express any symptoms of the mitochondrial disorder.

The potential for creating children from multiple parents is not limited to the halting of the passage of mitochondrial disorders. In May 2013, Shoukhrat Mitalipov and his colleagues at the Oregon Health and Science University published a milestone article describing the use of IVF technology to transfer genetic material from any nonsperm cell into a human egg, thereby generating a pre-implantation embryo from which human embryonic stem cells can be readily isolated and maintained in the laboratory (Cell, 153:1228-38, 2013). One of many potential outcomes of this research is the ability to create a human embryo without any male genetic contribution—by transferring the nucleus of a somatic cell from one woman into an enucleated egg of another. Embryos could also be made from more than three genetic parents by merging multiple embryos into a single chimeric infant, as has already been achieved in rhesus monkeys (Cell, 148:285-95, 2012).

read more 

Mitochondrial diseases, which are passed down maternally, affect one in 6,500 children worldwide and result from mutations in mitochondrial DNA (mtDNA). They can cause a variety of incurable human pathologies, including heart problems, liver failure, brain disorders, blindness, hearing loss, myopathy and death.In order to prevent defective mtDNA from being passed to a child, scientists have developed a new procedure that modifies standard in-vitro fertilization (IVF) technology to create an embryo from the eggs of two females, transferring the nuclear DNA from the egg of the female carrying mitochondrial defects into the enucleated cytoplasm of a donor egg that harbors nonmutated mtDNA, and sperm obtained from one male. The resulting embryo is then implanted into the uterus of the woman with the mitochondrial disorder.IVF itself raised many legal and ethical questions when it first appeared in the 1970s – terms such as “desiglner babies” and “playing God” were thrown around quite liberally – though it has now become widely accepted. This new procedure, however, raises new ones, such as: who are the legal parents of such a child? Would the child have the right to know the identity of all his/her gene donors? And would this just be taking one step closer down the path towards an era of “consumer eugenics”?News source: http://bit.ly/GzBnVVImage source: Holding egg. Successful birth of the first frozen oocyte baby in India/OpenI
source 

Mitochondrial diseases, which are passed down maternally, affect one in 6,500 children worldwide and result from mutations in mitochondrial DNA (mtDNA). They can cause a variety of incurable human pathologies, including heart problems, liver failure, brain disorders, blindness, hearing loss, myopathy and death.

In order to prevent defective mtDNA from being passed to a child, scientists have developed a new procedure that modifies standard in-vitro fertilization (IVF) technology to create an embryo from the eggs of two females, transferring the nuclear DNA from the egg of the female carrying mitochondrial defects into the enucleated cytoplasm of a donor egg that harbors nonmutated mtDNA, and sperm obtained from one male. The resulting embryo is then implanted into the uterus of the woman with the mitochondrial disorder.

IVF itself raised many legal and ethical questions when it first appeared in the 1970s – terms such as “desiglner babies” and “playing God” were thrown around quite liberally – though it has now become widely accepted. This new procedure, however, raises new ones, such as: who are the legal parents of such a child? Would the child have the right to know the identity of all his/her gene donors? And would this just be taking one step closer down the path towards an era of “consumer eugenics”?

News source: http://bit.ly/GzBnVV

Image source: Holding egg. Successful birth of the first frozen oocyte baby in India/OpenI

source 

By reducing the expression of a gene known as mTOR, the scientists extended the average lifespan of a group of mice by around 20%. But the increased lifespan didn’t affect all tissues and organs in the same way - while the mice retained better memory and balance as they aged, their bones deteriorated more quickly than usual.Read more: http://1.usa.gov/17rdZD5 via NIH
source 

By reducing the expression of a gene known as mTOR, the scientists extended the average lifespan of a group of mice by around 20%. But the increased lifespan didn’t affect all tissues and organs in the same way - while the mice retained better memory and balance as they aged, their bones deteriorated more quickly than usual.

Read more: http://1.usa.gov/17rdZD5 via NIH

source 

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.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.Read the full article: http://www.sci-news.com/genetics/article00701.html

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.

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.

Read the full article: http://www.sci-news.com/genetics/article00701.html