Phosphorylation of the high-mobility-group-like protein P1 by casein kinase-2

The nuclear protein P1 (molecular mass 53 kDa), found in all mammalian cell types and tissues so far tested, is an excellent substrate for casein kinase-2. The number of phosphate groups on P1 is 20-30/molecule; the phosphorylation sites are distributed throughout the molecule. The phosphate is present as serine phosphate and possibly threonine phosphate. Proteolytic digestion with Staphylococcus aureus V8 protease of 32P-labelled P1 both in vivo and in vitro revealed that casein kinase-2 may be one of the kinases responsible for the phosphorylation in vivo.     

Studies on the biosynthesis of gramicidin S in a cell-free system from Bacillus brevis. Further attempts to elucidate its mechanism of synthesis

1. The pH optima for the incorporation of (14)C-labelled amino acids into gramicidin S by an 11000g cell-free extract from Bacillus brevis have been determined. The pH optima for leucine, proline, phenylalanine, ornithine and valine were 7.5-7.7, 7.5-7.7, 7.7-7.9, 7.7-7.9 and 8.0-8.2 respectively. Hence the greatest difference in pH optima existed between leucine and valine, where it was 0.5pH unit. 2. The 11000g cell-free extract incorporated into gramicidin S only the l-isomers of valine, proline and ornithine. However, both isomers of leucine are utilized and the experiments indicate that a leucine racemase exists in the 11000g cell-free extract. With phenylalanine the l-isomer is utilized much more effectively than the d-isomer. This is noteworthy since it is the d-isomer that occurs in gramicidin S. The experiments indicate that conversion of the l-isomer into the d-form takes place at a stage beyond that of the free amino acid.     

Gene-culture coevolutionary theory

Gene-culture coevolutionary theory is a branch of theoretical population genetics that models the transmission of genes and cultural traits from one generation to the next, exploring how they interact. These models have been employed to examine the adaptive advantages of learning and culture, to investigate the forces of cultural change, to partition the variance in complex human behavioral and personality traits, and to address specific cases in human evolution in which there is an interaction between genes and culture.     

The evolutionary consequences of niche construction: a theoretical investigation using two-locus theory

This paper addresses the joint evolution of environment-altering (niche constructing) traits, and traits whose fitness depends on alterable sources of natural selection in environments. We explore the evolutionary consequences of this niche construction using a two-locus population genetic model. The novel conclusions are that niche construction can (1) cause evolutionary inertia and momentum, (2) lead to the fixation of otherwise deleterious alleles, (3) support stable polymorphisms where none are expected, (4) eliminate what would otherwise be stable polymorphisms, and (5) influence disequilibrium. The results suggest that the changes that organisms bring about in their niche can themselves be an important source of natural selection pressures, and imply that evolution may proceed in cycles of selection and niche construction.     

The metaphase specific phosphorylation of HMG I

In vivo labelling of HeLa cells arrested in metaphase with [32P]-phosphate and in vitro phosphorylation of HMG I with the partially purified growth associated H1 kinase was used to study metaphase specific phosphorylation of HMG I. It was found that threonine 53 and 78 became phosphorylated. These amino acids are embedded in respectively the sequence PTPKR and TPGRK which are similar to the sequences phosphorylated by the growth associated H1 kinase.     

Species difference in adaptive use of public information in sticklebacks

Animals foraging on variable food sources can refine their estimates of patch quality by monitoring the success of others (i.e. collect 'public information'). Here, we show that both three-spined sticklebacks (Gasterosteus aculeatus) and nine-spined sticklebacks (Pungitius pungitius) use past cues provided by others to locate food but only nine-spined sticklebacks use prior public information to assess patch quality, regardless of whether demonstrators were conspecifics or heterospecifics. Moreover, nine-spined but not three-spined sticklebacks preferentially hid in vegetation during the demonstration, a position from which they could observe both patches simultaneously and collect public information. We conclude that species differences in the use of public information can be explained by variations in habitat choice and response to predation. Our findings expand current understanding of the scope of public-information use in animals by showing that fishes can use public-information in a foraging context and from heterospecifics. The study suggests that public-information use is an adaptation that allows animals vulnerable to predation to acquire valuable foraging information at low risk.