Johan Jakobsson and his team tries to understand how the human brain is so different in complexity and size to the brains of other great apes, even though our coding genome is almost identical. In an attempt to answer that, they used induced pluripotent stem cells (iPSCs) to generate neural progenitors from both humans and chimpanzees, which is our closest living relative in evolutionary terms. This enabled them to identify a Zinc finger protein (ZNF) specifically expressed in humans and not chimpanzees and demonstrate that the human-specific ZNF (named ZNF558) is crucial for both mitochondrial homeostasis and early human brain development. A particularly intriguing piece of information provided in this study, is that the ZNF558 expression is controlled by a non-coding DNA sequence, which is structurally different between humans and chimpanzee.
In contrast to the coding parts of our genomes, where humans and chimpanzees are close to identical, the non-coding parts show great interspecies variation. This study provides a concrete example of how the non-coding part of the genome can influence the process of brain development differently between humans and chimpanzees.
Related links for further reading:
The press release including an interview with Prof. Johan Jakobsson at the homepage of the Medical faculty, Lund university.
The full article "A human-specific structural variation at the ZNF558 locus controls a gene regulatory network during forebrain development” published in Cell Stem Cells.
The homepage of Prof. Johan Jakobsson's research group Molecular Neurogenetics.