Navigation Links
Marsupial genome reveals insights into mammalian evolution

The genetic code of marsupials has now been documented for the first time. An international team led by Kathy Belov from the University of Sydney's Faculty of Veterinary Science published an analysis of the marsupial genome in the open access journal PLoS Biology. The paper details the evolution of an important cluster of immune genes known as the MHC using available genome sequences of the gray, short-tailed opossum (Monodelphis domestica), a marsupial found in South America.

"Mapping the opossum MHC has allowed us to deduce what the MHC of ancestral mammals looked like," says Belov. "We think it contained several different types of immune genes in a single complex. These genes are no longer found in a single complex in any living animal but are scattered over various chromosomes. We have named this complex 'The Immune Supercomplex.'"

Belov et al. found that while the size and complexity of the opossum MHC is closer to eutherian (placental) mammals, its organization is closer to fish and birds. "The clues we unearthed by looking at different genomes are also helping us to understand how our own intricate immune system evolved from the relatively simple immune system seen in lower vertebrates such as birds and fish," says Belov.

"Interest in marsupial and monotreme genomes comes from their important positions in vertebrate evolution," says Belov. (Monotremes are egg-laying mammals, represented today by only the platypus and echidna.) "Comparing genes of placental mammals, such as the human and the mouse, is not very efficient because their genes can be so similar it is hard to pinpoint regions that remain unchanged because they serve a particular purpose. In contrast, comparison of distantly related genes, such as the chicken and human, can be difficult, because the sequences are so different."

"Marsupial and monotreme genomes fill this gap. They are easily aligned with placental mammal genomes, yet are different enough to pinpo int regions that have important functions and therefore have been conserved for long periods of time. The monotremes split off from other mammals 210 million years ago. The remaining marsupials split from the main (placental) group about 180 years ago."

Significantly, the authors also found data supporting the idea that there was an ancient relationship between the MHC and another critical component of the immune system, the natural killer complex (NKC), which contains natural killer (NK) cell receptor loci. This "immune supercomplex," which no longer exists in modern genomes, performed the MHC functions in ancestral mammals. "Understanding the immune system of marsupials and monotremes will help us to conserve our native species," Belov says.


'"/>

Source:Public Library of Science


Related biology news :

1. Man and mouse share genome structures
2. Whole genome fine map of rice completed
3. Study finds more than one-third of human genome regulated by RNA
4. A bacterial genome reveals new targets to combat infectious disease
5. Scientists decipher genome of fungus that can cause life-threatening infections
6. Highly adaptable genome in gut bacterium key to intestinal health
7. Fleshing out the genome
8. Agilent Technologies new genome analysis technology set to accelerate Australia fight against mesothelioma
9. wFleaBase: the Daphnia genome database
10. NHGRI targets 12 more organisms for genome sequencing
11. Chimp genome reveals a retroviral invasion
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:4/26/2016)... , April 27, 2016 ... "Global Multi-modal Biometrics Market 2016-2020"  report to their ... , The analysts forecast the global ... of 15.49% during the period 2016-2020.  ... of sectors such as the healthcare, BFSI, transportation, ...
(Date:4/14/2016)... , April 14, 2016 ... Malware Detection, today announced the appointment of Eyal ... new role. Goldwerger,s leadership appointment comes at ... heels of the deployment of its platform at several ... biometric technology, which discerns unique cognitive and physiological factors, ...
(Date:3/29/2016)... 29, 2016 LegacyXChange, Inc. (OTC: ... and SelectaDNA/CSI Protect are pleased to announce our successful ... a variety of writing instruments, ensuring athletes signatures against ... collectibles from athletes on LegacyXChange will be assured of ... DNA. Bill Bollander , CEO states, ...
Breaking Biology News(10 mins):
(Date:4/27/2016)... SILVER SPRING, Md. and RESEARCH ... -- United Therapeutics Corporation (NASDAQ: UTHR ) announced ... Co-Chief Executive Officer, of United Therapeutics will provide an ... Deutsche Bank 41 st Annual Health Care Conference. ... May 5, 2016, at 10:00 a.m. Eastern Time, and ...
(Date:4/27/2016)... ... April 27, 2016 , ... A compact ... Emission Tomography) and MRI (Magnetic Resonance Imaging) in existing third-party MRI systems. PET ... treatments in small animal subjects. Simultaneous PET/MRI imaging offers a solution to many ...
(Date:4/27/2016)... , April 27, 2016 ... research report with specific focus on US, EU, ... Japan , to the healthcare business intelligence ... library. Complete report on the Flow ... companies and supported with 282 tables and figures ...
(Date:4/26/2016)... ... April 26, 2016 , ... Heidelberg Instruments, a leader in ... for its Volume Pattern Generator (VPG) line of lithography systems. The breakthrough VPG+ ... well as a solution for mid volume direct write lithography applications. It ...
Breaking Biology Technology: