Silkworm, Bombyx mori
Amino acids are chiral molecules; They exist in left and right handed versions. Only the L- forms of amino acids are used in proteins. Curiously, many insects have high levels of D- forms of amino acids. The silkworm, Bombyx mori, has high levels of D-serine. What does it do?
A group of scientists* studied the location and metabolism of D-serine in silkworm. They found it along with serine racemase (an enzyme that interconverts L- and D-serine) in multiple locations….
Source: Living With Insects Blog