Strong paternal influence on the inheritance of mutations in chimpanzees
16 June 2014
DNA is the material in which the genetic information of an organism is fixed. This DNA is a mixture of the DNA of the parents. From generation to generation it is inherited, including newly created changes in the genetic code. These mutations are in humans mostly derived from the father. To investigate whether this is also the case in chimpanzees, the DNA sequences from nine members of a chimpanzee family were determined.
In humans, each individual inherits roughly 70 new mutations of his parents. About 75% of these mutations is derived from the father and is influenced by the age of the father. Mutations in the DNA of germ cells can be inherited by the offspring and therefore are important in the context of genetic disorders and evolutionary processes.
The availability of unique DNA material from a chimpanzee colony that in the past was housed at the BPRC has provided the opportunity to study whether this process is carried out in a similar manner in chimpanzees. It was found that, similar to the human situation, the majority of the mutations in the progeny is inherited from the father. However, in chimpanzees, the age of the father had a much stronger effect on the mutation rate than in humans. As a result, about 90% of the new mutations in the offspring was derived from the father. Chimpanzees, as a result of their polygamic relationships, have eveolved to produce more sperm than humans, and this may explain this difference. Their testicles are more than three times as big as in humans. Therefore, it is likely that there are more sperm producing cycli, increasing the chance for new emerging mutations. More work in other species it is needed to be able to confirm this.
This study, conducted by a partnership between scientists from Wellcome Trust for Human Genetics in Oxford and the BPRC, was published in Science.