Population-level differentiation

Responses at the population level may clarify the potential role of chemosignals in the diversification of Liolaemus. The chemical profiles of the precloacal secretions of two populations of L. fabiani indicate that they show some level of differentiation (Escobar et al. 2003). However, populations of L. lemniscatus and L. tenuis did not show clear patterns of recognition of their own population vs. other populations apparently, chemosignals may not play a key role in the speciation process of Liolaemus (unpublished data). 

In this contribution a population balance model of influenza A vims replication during vaccine production in Madin-Darby canine kidney (MDCK) cell cultures is developed. Differentiation on the population level is described by a degree of infection, which is proportional to the amount of intracellular viral proteins. This can be measured directly using flow cytometry. It is shown that the model shows reasonable agreement with experimental data, although not all details of the inner dynamics can be fully reproduced. 

Stark JD, Bamfo S. 2002. Population-level outcomes of differential susceptibility among life stages of the aphid parasitoid Diaeretiella rapae to pesticides. In Proceedings of the 1st International Symposium on Biological Control of Arthropods, Honolulu, Hawaii, January 14—18, 2002. Forest Service (WA) US Department of Agriculture, p. 314-317. 

SRPAC is a scattering variant of time-differential perturbed angular correlation (TDPAC). In TDPAC, an intermediate nuclear level is populated from above after the decay of a radioactive parent. If this nuclear level exhibits hyperfine... 

Figure 3.2. Stable isotope labeling for quantifying differential protein expression. Cell populations are grown in either 14N or 15N containing medium. Protein lysates are fractionated and separated by 2D gel electrophoresis. Protein spots are excised, digested with trypsin and the mass of the resulting peptides is determined by mass spectrometry. The presence of 15N results in a shift and creates two peaks for each peptide. The ratio of intensities of the peaks is indicative of the relative expression levels of the proteins. Spot A contains a protein that is expressed at similar levels in both cell pools. Spot B contains a protein that is expressed at higher levels in cell pool 2. Figure adapted from Oda et al. (1999).

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