The researchers also attempted to determine which characteristics of the platypus were linked to reptiles at the DNA level. Interestingly, the platypus lacks nipples, so its young nurse through the abdominal skin. The researchers also found genes that support egg laying - a feature of reptiles - as well as lactation - a characteristic of all mammals. The chicken genome was chosen because it represents a group of egg-laying animals, including extinct reptiles, which passed on much of their DNA to the platypus and other mammals over the course of evolution. They found that the platypus shares 82 percent of its genes with these animals. вЂњBut as weird as this animal looks, its genome sequence is priceless for understanding how mammalian biological processes evolved.вЂќДЄs part of their analysis, the researchers compared the platypus genome with genomes of the human, mouse, dog, opossum and chicken. вЂњAt first glance, the platypus appears as if it was the result of an evolutionary accident,вЂќ said Francis S. The project was largely funded by the National Human Genome Research Institute (NHGRI), part of the National Institutes of Health, and includes scientists from eight countries. The study analyzes the genome sequence of a female platypus from New South Wales, Australia.

The comparison also will allow scientists to date the emergence of genes and traits specific to mammals. вЂњWhat is unique about the platypus is that it has retained a large overlap between two very different classifications, while later mammals lost the features of reptiles,вЂќ said Wes Warren, Ph.D., research assistant professor of genetics, who led the project.Д¬omparison of the platypus genome with the DNA of humans and other mammals, which diverged later, and the genomes of birds, whose ancestors branched off an estimated 315 million years ago, can help scientists fill gaps in their understanding of mammalian evolution. The platypus represents the earliest offshoot of the mammalian lineage some 166 million years ago from primitive ancestors that had features of both mammals and reptiles. вЂњBy comparing the platypus genome to other mammalian genomes, weвЂ™ll be able to study genes that have been conserved throughout evolution.вЂќ Wilson, Ph.D., director of The Genome Center at Washington University and the paperвЂ™s senior author. вЂњThe fascinating mix of features in the platypus genome provides many clues to the function and evolution of all mammalian genomes,вЂќ said Richard K. Males possess hind leg spurs that can deliver pain-inducing venom to its foes competing for a mate or territory during the breeding season. One of only two mammals that lays eggs, the platypus also sports a duck-like bill that holds a sophisticated electrosensory system used to forage for food underwater.

The platypus, classified as a mammal because it produces milk and is covered in fur, also possesses features of reptiles, birds and their common ancestors, along with some curious attributes of its own. The mammal has features of reptiles, birds and their common ancestors as well as some unique attributes. School of Medicine researchers have sequenced the duck-billed platypus genome. An analysis of the genome, published in the journal Nature, can help scientists piece together a more complete picture of the evolution of all mammals, including humans.

The duck-billed platypus: part bird, part reptile, part mammal - and the genome to prove it.ДЄn international consortium of scientists, led by the School of Medicine, has decoded the genome of the platypus, showing that the animalвЂ™s peculiar mix of features is reflected in its DNA.

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