Artificial Selection Essay

Many different species have been altered through selective breeding. Selective breeding is a very common practice in the livestock breeding and has impacted the livestock industry greatly by using information obtain from research of the myostatin protein. History of selective breeding of cattle In the 1800s the demand for a better quality as well as quantity of beef was high. Cattle breeders begin to breed select breeds of cattle that appeared larger together in hopes of producing offspring with a larger quantity of meat.

The selective breeding began with the Durham Shorthorns and Friesian cattle. (Lee, 2004) The result of the selective breeding produced 3 different strands of cattle breeds the Belgian Blue, Piedmontes and Parthenias. These breeds of cattle all have one similarity, that has proved to be very valuable, the inactive Myostatin protein.

Due to the inactive Myostatin protein these cattle produce roughly 20 % more meat than other cattle. The Belgian Blue cattle are a common breed of cattle in the beef and livestock industry representing the double muscle trait caused by the inactive Myostatin protein.

Myostatin In 1997 a research team from John Hopkins School of Medicine led by geneticists Dr. Se-Jin Lee and Alexandra McPherron released information from their research on how proteins regulate the growth of tissue in mice. Through their research the team unintentionally discovered the growth differentiation factor 8 (GDF-8) also known as Myostatin protein. With the discovery of the Myostatin protein the team decided to produce a mutant strain of mice that did not have the Myostatin protein.

The results showed that the mutant mice had 3 times the muscle tissue than that of a regular mouse. The research showed that with the absence of the myostatin protein the muscle tissue did not have anything to regulate the size; therefore muscle tissue was extremely larger. The Myostatin (GDF-8) protein is a member of the transforming growth factor ? superfamily of secreted growth and differentiation factor. (Lee, 2004) Myostatin is a secreted protein that acts as a negative regulator of skeletal muscle mass.

During embryogenesis, myostatin is expressed by cells in the myotome and in developing skeletal muscle and acts to regulate the final number of muscle fibers that are formed. (Lee, 2004) The research of Dr Se-Jin Lee and his colleagues brought the discovery of the Myostatin protein to the forefront of science. However they were not the only group of researcher. Two other research group have also reported finding on the Myostatin mutation. Micheal Georges of the University