A partially EU-funded project carrying out research into muscle development in pigs has discovered the existence of a new gene called ZBED6 that is unique to placental mammals. The newly discovered gene originates from a ‘jumping gene’ that originated in a primitive mammal more than 150 million years ago. The study is published in the journal PLoS (Public Library of Science) Biology.
The research team, from Uppsala University in Sweden, the Swedish University of Agricultural Sciences, and the Broad Institute in the US received an Advanced Investigator Grant from the European Research Council (ERC), among other funding sources. A key focus of the research was to find a genetic answer to why domestic pigs develop more muscle and store less fat than their ancestors, wild boar.
‘This is a result of the systematic selection that has been ongoing for the last 60 years to breed pigs that produce the lean meat that consumers prefer,’ says Professor Leif Andersson from Uppsala University, leader of the research team. ‘This explains why a pork chop today contains much less fat compared with the pork chops produced a hundred years ago.’
During their research the team discovered a mutation in a non-coding DNA sequence which is responsible for regulating the expression of a growth factor called IGF2. This mutation makes a significant contribution to the differences in muscle growth between pigs and wild boar.
‘We have now, in collaboration with researchers at the Broad Institute, used a sophisticated molecular method to isolate the protein that binds the DNA sequence that is altered in pigs,’ says Lin Jiang, a PhD student working on the project. ‘Surprisingly, the protein was previously unknown and we named it ZBED6. The protein is present in all placental mammals including humans.’
‘Jumping genes’ were discovered in 1983 and ZBED6 has evolved from the same ‘family’ of genes. ZBED6 regulates not only the expression of the IGF2 growth factor, but possibly thousands of other genes in mammals.
‘The results indicate that we have discovered a new ‘orchestra conductor’ that controls the activities of many genes in the mammalian cell,’ says Professor Andersson. ‘It will be very exciting to further study the biological significance of ZBED6 and find out to which extent the action of this factor influences various diseases in humans. The discovery provides new basic knowledge concerning the evolution of placental mammals and is of considerable biomedical significance.’