RIS IB Biology

estricted animals that are classified as vulnerable, endangered, or critically endangered, including the Asiatic black bear and Saiga antelope.”

including animal DNA and potential allergens such as soy or nuts.

mislabelling of TCMs

multiple samples that contained DNA from animals listed as trade-restricted

cloned the receptor and used this to genetically engineer human blood stem cells.

mature T cells that can attack HIV in tissues where the virus resides and replicates.

CD4 cells are white blood cells that are an important component of the immune system, helping to fight off infections.

CD4 "helper" T cells

engineering stem cells to form immune cells that target HIV is effective in suppressing the virus in living tissues in an animal model

increased

HIV in the blood decreased.

The engineered stem cells developed into a large population of mature, multi-functional HIV-specific CD8 cells that could specifically target cells containing HIV proteins. The researchers also discovered that HIV-specific T cell receptors have to be matched to an individual in much the same way an organ is matched to a transplant patient.

Expanding on previous research providing proof-of-principle that human stem cells can be genetically engineered into HIV-fighting cells

In this current study, the researchers similarly engineered human blood stem cells and found that they can form mature T cells that can attack HIV in tissues where the virus resides and replicates. They did so by using a surrogate model, the humanized mouse, in which HIV infection closely resembles the disease and its progression in humans.

increased, while levels of HIV in the blood decreased. CD4 cells are white blood cells that are an important component of the immune system, helping to fight off infections. These results indicated that the engineered cells were capable of developing and migrating to the organs to fight infection there.

Future applications of this work could include tiny yeast-based machines that can be dropped into water supplies to detect contaminants, and yeast that records environmental conditions during the manufacture of biofuels to determine if improvements can be made to the production process.

help to improve things such as pollution monitoring and cleaner fuels

the offspring of parents who experience famine are at heightened risk for developing schizophrenia, some research suggests — perhaps because of the chemical signatures on the genes that parents pass on.

in some people with autism, epigenetic markers had silenced the gene which makes the receptor for the hormone oxytocin. Oxytocin oils the brain’s social circuits, and is critical in cementing relationships; a brain short on receptors for it would most likely struggle in social situations.

In one large study of people with schizophrenia, researchers at Johns Hopkins are analyzing blood and other data to see whether the degree of epigenetic variation is related to the inherited risk of developing the disorder. In another, researchers at Tufts are studying the genes of animals dependent on opiates to see how epigenetic alterations caused by drug exposure affect the opiate sensitivity of the animals’ offspring.

Epigenetics examines the inheritance of characteristics that are not set out in the DNA sequence.

important factors are the histones, a kind of packaging material for the DNA, in order to store DNA in an ordered and space-saving way. It is now clear that these proteins have additional roles to play. Depending on the chemical group they carry, if they are acetylated or methylated, they permanently activate or deactivate genes.

New methods now allow researchers to sometimes directly show which genes have been activated or deactivated by the histones

The genetic information of the DNA is passed on along with the relevant epigenetic information for the respective cell type.

A similar question remains for the inheritance of the epigenetic characteristics from parents to offspring. They now know that when the gametes are formed, certain epigenetic markers remain and are passed on to the offspring. The questions, which are currently being researched, are how much and which part of the epigenetic information is preserved and subsequently inherited.

Diet and epigenetics appear to be closely linked. The most well known example is that of the Agouti mice: they are yellow, fat and are prone to diabetes and cancer. If Agouti females are fed with a cocktail of vitamin B12, folic acid and cholin, directly prior to and during pregnancy, they give birth to mainly brown, slim and healthy offspring. They in turn mainly have offspring similar to themselves.

Environmental factors, which change the characteristics of an individual and are then passed on to its offspring, do not really fit into Darwin’s theory of evolution. According to his theory, evolution is the result of the population and not the single individual. “Passing on the gained characteristics fits more to Lamarck’s theory of evolution”, says Paro.

The molecule turned on genes that make cartilage components called aggrecan and type II collagen. Tests of mice with cartilage damage similar to osteoarthritis showed that kartogenin injections lowered levels of a protein called cartilage oligomeric matrix protein. People with osteoarthritis have an excess of the protein, which is considered a marker of disease severity.

kartogenin inhibits a protein called filamin A in the mesenchymal stem cells

Genetic diversity is created in a colony when a queen mates with many male bees

less likelihood of potentially pathogenic bacteria showing up in genetically diverse honey bee colonies

individual bees and their symbionts can enhance the overall health of a colony when it is genetically diverse

increased resistance to colonization by pathogens or through the production of nutrients by these microbes

Only microscopic amounts of DNA are left on the skeletons, including all the bacteria that lived on the animals. No usable DNA is therefore often found in bone, but mammoth hair is plentiful. Shampooed and bleached and digested, the hair, even at 18,000 years old, can have 90% of the DNA left. The genome shows 4 different "races" of this species. Research has also shown the recreated blood of mammoth. It doesn't decrease its oxygen capacity at the low temperatures the mammoth had to endure. That increased oxygen-offloading ability was one of the essential physiological changes evolved especially for this species, just like the Yuka kidney.

Cloning the mammoth has been an aim of Japanese scientists for several years. They discovered almost intact bone marrow from a thigh bone in Yakutsk and hope to use a female elephant for what is obviously more than a simple experiment within the next 5 years.

cording to the study by the University of Edinburgh.

Meanwhile, creatures who reproduce asexually are more likely to be lumbered with disease-causing genes

Combining the genes of two parents – rather than one in the case of fruit flies, stick insects and other animals – allows for damaging DNA to be removed within a few generations.

h longer, a

or muc

This is because individuals who inherit healthy genes tend to flourish and pass on their DNA to the next generatio