Genome analysis of the platypus reveals unique signatures of evolution.
Warren WC., Hillier LW., Marshall Graves JA., Birney E., Ponting CP., Grützner F., Belov K., Miller W., Clarke L., Chinwalla AT., Yang S-P., Heger A., Locke DP., Miethke P., Waters PD., Veyrunes F., Fulton L., Fulton B., Graves T., Wallis J., Puente XS., López-Otín C., Ordóñez GR., Eichler EE., Chen L., Cheng Z., Deakin JE., Alsop A., Thompson K., Kirby P., Papenfuss AT., Wakefield MJ., Olender T., Lancet D., Huttley GA., Smit AFA., Pask A., Temple-Smith P., Batzer MA., Walker JA., Konkel MK., Harris RS., Whittington CM., Wong ESW., Gemmell NJ., Buschiazzo E., Vargas Jentzsch IM., Merkel A., Schmitz J., Zemann A., Churakov G., Kriegs JO., Brosius J., Murchison EP., Sachidanandam R., Smith C., Hannon GJ., Tsend-Ayush E., McMillan D., Attenborough R., Rens W., Ferguson-Smith M., Lefèvre CM., Sharp JA., Nicholas KR., Ray DA., Kube M., Reinhardt R., Pringle TH., Taylor J., Jones RC., Nixon B., Dacheux J-L., Niwa H., Sekita Y., Huang X., Stark A., Kheradpour P., Kellis M., Flicek P., Chen Y., Webber C., Hardison R., Nelson J., Hallsworth-Pepin K., Delehaunty K., Markovic C., Minx P., Feng Y., Kremitzki C., Mitreva M., Glasscock J., Wylie T., Wohldmann P., Thiru P., Nhan MN., Pohl CS., Smith SM., Hou S., Nefedov M., de Jong PJ., Renfree MB., Mardis ER., Wilson RK.
We present a draft genome sequence of the platypus, Ornithorhynchus anatinus. This monotreme exhibits a fascinating combination of reptilian and mammalian characters. For example, platypuses have a coat of fur adapted to an aquatic lifestyle; platypus females lactate, yet lay eggs; and males are equipped with venom similar to that of reptiles. Analysis of the first monotreme genome aligned these features with genetic innovations. We find that reptile and platypus venom proteins have been co-opted independently from the same gene families; milk protein genes are conserved despite platypuses laying eggs; and immune gene family expansions are directly related to platypus biology. Expansions of protein, non-protein-coding RNA and microRNA families, as well as repeat elements, are identified. Sequencing of this genome now provides a valuable resource for deep mammalian comparative analyses, as well as for monotreme biology and conservation.