Phytoene desaturase (lycopene-forming) of a bacterial phytoene desaturase into transgenic tomatos increased the lycopene content without the need to alter several of the plants enzymes. This approach was later used in rice to increase its β-carotene content resulting in the Golden Rice project. Phytoene desaturase (lycopene-forming) Phytoene desaturase (lycopene-forming) (CrtI, "four-step phytoene desaturase") (, "15-cis-phytoene:acceptor oxidoreductase (lycopene-forming)") are enzymes found in archaea, bacteria and fungi that are involved in carotenoid biosynthesis. They catalyze the conversion of colorless 15-"cis"-phytoene into a bright red lycopene in a biochemical pathway called the poly-trans pathway. The same process in plants and cyanobacteria utilizes four separate enzymes in
Labrador Retriever coat colour genetics characterized in mice and other mammals. Initial genetic studies of coat colour in dogs published in the 1950s concluded that there were two main genes involved, one distinguishing blacks from browns, and the other distinguishing blacks from reds and yellows. A 1977 study using crosses within a population of purebred Labradors showed the involvement of two specific genes in production of the three main coat colours of Labradors and described the underlying genetics of these colour varieties. The three recognised colours of Labrador Retrievers result from differences in two genetic loci that affect pigment expression. The first of these affects