History of genetics of the fruit fly "Drosophila melanogaster". In 1928, Frederick Griffith showed that genes could be transferred. In what is now known as Griffith's experiment, injections into a mouse of a deadly strain of bacteria that had been heat-killed transferred genetic information to a safe strain of the same bacteria, killing the mouse. A series of subsequent discoveries led to the realization decades later that the genetic material is made of DNA (deoxyribonucleic acid). In 1941, George Wells Beadle and Edward Lawrie Tatum showed that mutations in genes caused errors in specific steps in metabolic pathways. This showed that specific genes
Neuraminic acid considerably: acetyl, lactyl, methyl, sulfate and phosphate groups have been found. The name "neuraminic acid" was introduced by German scientist E. Klenk in 1941, in reference to the brain lipids from which it was derived as a cleavage product. The symbol commonly used for neuraminic acid is Neu, and the residue is typically found with additional chemical modifications in biological systems. As a family, these residues are known as sialic acids. For example, "N"-acetylneuraminic acid, Neu5Ac, is typical in human glycoproteins. Among their many biological functions, these structures are substrates for neuraminidase enzymes which cleave neuraminic acid residues. Human flu