Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Wertheim cung cấp cho các bạn kiến thức về ngành y đề tài: Marsupials and monotremes sort genome treasures from junk. | Minireview Marsupials and monotremes sort genome treasures from junk Matthew J Wakefield and Jennifer AM Graves Addresses Division of Immunology and Genetics John Curtin School of Medical Research and fARC Centre for Kangaroo Genomics Research School of Biological Science The Australian National University Canberra 0200 Australia. Correspondence Jennifer AM Graves. E-mail Published 28 April 2005 Genome Biology 2005 6 218 doi gb-2005-6-5-2l8 The electronic version of this article is the complete one and can be found online at http 2005 6 5 218 2005 BioMed Central Ltd Abstract A recent landmark paper demonstrates the unique contribution of marsupials and monotremes to comparative genome analysis filling an evolutionary gap between the eutherian mammals including humans and more distant vertebrate species. Sequencing of a variety of mammalian and other vertebrate genomes is now proceeding apace and one major goal of this work is to interpret the massive amounts of data from the Human Genome Project by aligning sequence and distinguishing conserved elements from the background of variable sequence phylogenetic footprinting . Sequence data from mammals that are more or less closely related to humans chimpanzee mouse dog and more distantly related vertebrates birds fish span 450 million years of evolution. But there is still an awkward gap precisely in the region of the tree from which genomic data are most needed species that are not so close that sequence comparison gives false-positive signals and not so far that the sequences are unalignable. Marsupials and monotremes the earliest groups of mammals to diverge fill this gap Figure 1 . All mammals produce milk and suckle their young but marsupials and monotremes are distinguished from eutherian placental mammals by differences in reproduction. Marsupials such as kangaroos and wallabies give birth to highly underdeveloped young and much of their development occurs while
