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A Gierer

Publications and source records attributed to A Gierer.

31 records · Page 2Linked to original sources
PubMed1975

Non-histone chromosomal proteins. Their isolation and role in determining specificity of transcription in vitro.

We describe a method for fractionation of chromatin components by selective dissociation with salt in buffers containing 5 M urea in combination with cromatography on hydroxyapatite at 4 degrees C. This results in two histone and four non-histone fractions which are recovered in high yield and with minimal proteolytic contamination. Template capacity measurements of the isolated chromatins and pre-saturation competition hybridization experiments support the idea that a group of non-histone proteins activate the transcription of specific DNA sequences which were not transcribed from purified DNA to the same extent. In reconstitution experiments a non-histone protein fraction, NH4, prepared from lymphocyte chromatin by hydroxyapatite chromatography is shown to cause transcription in vitro of lymphocyte-specific RNA sequences. A subfraction with a molecular weight of 30 000 comprising 40% of the NH4 fraction protein is characteristic for this tissue and not found in liver chromatin.

Amino Acids↗
PubMedDate not supplied

Networks of gene regulation, neural development and the evolution of general capabilities, such as human empathy.

A network of gene regulation organized in a hierarchical and combinatorial manner is crucially involved in the development of the neural network, and has to be considered one of the main substrates of genetic change in its evolution. Though qualitative features may emerge by way of the accumulation of rather unspecific quantitative changes, it is reasonable to assume that at least in some cases specific combinations of regulatory parts of the genome initiated new directions of evolution, leading to novel capabilities of the brain. These notions are applied, in this paper, to the evolution of the capability of cognition-based human empathy. It is suggested that it has evolved as a secondary effect of the evolution of strategic thought. Development of strategies depends on abstract representations of one's own possible future states in one's own brain to allow assessment of their emotional desirability, but also on the representation and emotional evaluation of possible states of others, allowing anticipation of their behaviour. This is best achieved if representations of others are connected to one's own emotional centres in a manner similar to self-representations. For this reason, the evolution of the human brain is assumed to have established representations with such linkages. No group selection is involved, because the quality of strategic thought affects the fitness of the individual. A secondary effect of this linkage is that both the actual states and the future perspectives of others elicit vicarious emotions, which may contribute to the motivations of altruistic behaviour.

Biological Evolution↗