"Knockout mice" gets him the noble prize

They must be grateful to the mice.Why shouldn't they be?
No scientists work to win noble prize.They just work to
investigate things.Naturally those who investigate are the
ones who are going to discover.The discovery in itself is "the
Greatest prize"for a scientist.That's what gives him the
greatest satisfaction and happiness.Maybe the noble prize
brings him happiness,the second time, for that old discovery.

Who am I talking about?Yes,the winners of this year Noble
prize in medicine.Two American scientists, Mario Capecchi
and Oliver Smithies, and Briton Martin Evans are the ones
who won it.They were awarded "for their discoveries of
principles for introducing specific gene modifications in mice
by the use of embryonic stem cells".

Dopamine study

Mice living in the Duke University lab of Howard Hughes
Medical Institute investigator Marc G. Caron behaved as
though they were on drugs.They were not on drugs.So why
did they behave that way?The gene for "dopamine
transporter" had been knocked out from them.Dopamine
level must have risen in their brain.This is the same neurotransmitter that isimplicated in addiction, schizophrenia and Parkinson's disease.The transporter removes the released dopamine through uptake.This knockout mice helped them in understanding mechanism of dopamine regulation.

Oxytocin study



In this study
the normal functioning
gene for oxytocin was
knocked out from the study
mice.The mice were normal?
Yes,unexpectedly their reproductive behaviours were normal.
The knockout mice weren't completely normal.The role of oxytocin in lactation was confirmed, mothers deprived of oxytocin can't nurse their young. Mouse pups die within a day unless researchers inject the mothers with oxytocin.

One of the world's first microRNA knockout mouse study


"MicroRNAs are copied from DNA but do not contain code for protein. Rather, they are themselves active in controlling the activity of other genes, often by inducing destruction of protein-coding messenger RNAs or by preventing their activity in the cell."


The research team knocked out the microRNA gene,miR-155, in the embryonic stem cells.
They then transferred this mutation into mice.This knockout mice showed high susceptibility to infections.Immune cells performed poorly and the signs in lungs were similar to certain autoimmune diseases.

Thus ,and in many more ways, knockout mice study is providing us with informations that is becoming the shoulder for other scientists to look further ahead.