This is the fourth Marsupial genome, after the Tasmanian Devil and and some other non-Australian marsupial, to be sequenced. According to Professor Marilyn Renfree of the University of Melborune, “The tammar wallaby sequencing project has provided us with many possibilities for understanding how marsupials are so different to us.”
Macropus eugenii is the tammar wallaby. This aninal has the longest period of embryonic diapause of any known mammal, highly synchronized seasonal breeding and an unusual system of lactation, making it very interesting, and wallabys were already pretty interesting. The research coming out today in the journal Genome Biology provides a hitherto lacking understanding of marsupial gene evolution and hopes to have identified marsupial-specific genetic elements. There appear to be interesting results in the areas of reproduction (as mentioned), development, and the immune system.
One interesting finding is the identification of genes that code for immune products (antibiotics) that the mother wallaby producers and inserts into the offspring’s milk. I’m not sure, but I don’t think Placental mammals do that in any major way, but one can see how marsupials would benefit a great deal from this as offspring are highly altricial and thus vulnerable to infections for longer periods of time. Wallaby babies, in other words, spend the latter part of when placental animals are in utero outside the uterus in a pouch.
Here’s the reference to the paper:
Genome sequence of an Australian kangaroo, Macropus eugenii, provides insight into the evolution of mammalian reproduction and development
Marilyn B Renfree, Anthony T Papenfuss, Janine E Deakin, James Lindsay, Thomas Heider, Katherine Belov, Willem Rens, Paul D Waters, Elizabeth A Pharo, Geoff Shaw, Emily SW Wong, Christophe M Lefèvre, Kevin R Nicholas, Yoko Kuroki, Matthew J Wakefield, Kyall R Zenger, Chenwei Wang, Malcolm Ferguson-Smith, Frank W Nicholas, Danielle Hickford, Hongshi Yu, Kirsty R Short, Hannah V Siddle, Stephen R Frankenberg, Keng Yih Chew, Brandon R Menzies, Jessica M Stringer, Shunsuke Suzuki, Timothy A Hore, Margaret L Delbridge, Amir Mohammadi, Nanette Y Schneider, Yanqiu Hu, William OHara, Shafagh Al Nadaf, Chen Wu, Zhi-Ping Feng, Benjamin G Cocks, Jianghui Wang, Paul Flicek, Stephen MJ Searle, Susan Fairley, Kathryn Beal, Javier Herrero, Dawn M Carone, Yutaka Suzuki, Sumio Sagano, Atushi Toyoda, Yoshiyuki Sakaki, Shinji Kondo, Yuichiro Nishida, Shoji Tatsumoto, Ion Mandiou, Arthur Hsu, Kaighin A McColl, Benjamin Landsell, George Weinstock, Elizabeth Kuczek, Annette McGrath, Peter Wilson, Artem Men, Mehlika Hazar-Rethinam, Allison Hall, John Davies, David Wood, Sarah Williams, Yogi Sundaravadanam, Donna M Muzny, Shalini N Jhangiani, Lora R Lewis, Margaret B Morgan, Geoffrey O Okwuonu, San Juana Ruiz, Jireh Santibanez, Lynne Nazareth, Andrew Cree, Gerald Fowler, Christie L Kovar, Huyen H Dinh, Vandita Joshi, Chyn Jing, Fremiet Lara, Rebecca Thornton, Lei Chen, Jixin Deng, Yue Liu, Joshua Y Shen, Xing-Zhi Song, Janette Edson, Carmen Troon, Daniel Thomas, Amber Stephens, Laneksha Yapa, Tanya Levchenko, Richard A Gibbs, Desmond W Cooper, Terence P Speed, Asao Fujiyama, Jennifer AM Graves, Rachel J ONeill, Andrew J Pask, Susan M Forrest and Kim C Worley
Genome Biology (in press)
Renfree, MB Et Al (2011). Genome sequence of an Australian kangaroo, Macropus eugenii, provides insight into the evolution of mammalian reproduction and development Genome Biology, In Press