Bacterial artificial chromosome libraries are collections of large (100, 000 - 200,000 DNA base pair) DNA fragments that are made retrievable and manipulatable by insertion into a specialized vector. As resources for easily obtaining large amounts of DNA sequences for comparative purposes, for understanding the structure of eukaryotic genomes, and for expressing and manipulating genes and their phenotypic effects in developing embryos, BAC libraries are unsurpassed. However, constructing BAC libraries is beyond the abilities of most laboratories not specifically tailored for this purpose. This project will consist of constructing, archiving and disseminating to the international community of scientists BAC libraries from five species of Reptilia, including a bird. The five focal species will be Painted Turtle (Chrysemys picta), Tuatara (Sphenodon punctatus), South American Worm Lizard (an amphisbaenian; Amphisbaea alba), American Alligator (Alligator mississippiensis), and the flightless Emu (Dromaius novaehollandiae). In the event that an appropriate Tuatara sample is not available (a distinct possibility given its endangered status and restricted range in New Zealand), a BAC library from a snake will be constructed. Reptilia, consisting of birds as well as species commonly referred to as reptiles, are poorly studied from genetic, developmental, genomic and phylogenetic perspectives; although Reptilia are much more diverse than their sister group, the mammals, mammals are much better studied as model biological species. The construction and arraying of BAC libraries from these species will open up many new avenues of research into reptile genomics that were previously unapproachable. There will be many scientific uses for these BAC libraries, including facilitating acquisition of comparative DNA data for phylogenetic and comparative genomic purposes, and a better understanding of the function of genes responsible for many features first appearing in the reptiles, such as feathers, temperature-dependent sex determination, limb reduction and loss, and large-scale genome reduction compared to mammals. Thus these libraries will fill a major gap in our understanding of vertebrate genomics, a rapidly progressing discipline spurred on by the recent sequencing of the complete human, mouse and pufferfish genomes.
