The photosynthetic apparatus in plant cells is associated with membranes of
the thylakoids within the chloroplast and is embedded into a highly specia
lized Lipid matrix. Diacylglycerol galactolipids are common in thylakoid me
mbranes but are excluded from all others. Isolation of the gene DGD1, encod
ing a galactosyltransferase-like protein, now provides insights into assemb
ly of the thylakoid Lipid matrix and subcellular Lipid trafficking in Arabi
dopsis thaliana.