Bombyx mori to produce proteins, including pharmacological drugs, in the place of silk proteins. "Bombyx mori" females are also one of the few organisms with homologous chromosomes held together only by the synaptonemal complex (and not crossovers) during meiosis. Kraig Biocraft Laboratories has used research from the Universities of Wyoming and Notre Dame in a collaborative effort to create a silkworm that is genetically altered to produce spider silk. In September 2010, the effort was announced as successful. Researchers at Tufts developed scaffolds made of spongy silk that feel and look similar to human tissue. They are implanted during reconstructive surgery to
Crustacean larva (lecithotrophy). In species with normal development, eggs are roughly 1% of the size of the adult; in species with abbreviated development, and therefore more yolk in the eggs, the eggs may reach 1/9 of the adult's size. The post-larva of shrimp is called "parva", after the species "Acanthephyra parva" described by Henri Coutière, but which was later recognised as the larva of "Acanthephyra purpurea". In the marine lobsters, there are three larval stages, all similar in appearance. Freshwater crayfish embryos differ from those of other crustaceans in having 40 ectoteloblast cells, rather than around 19. The larvae show abbreviated development,