Biomedical subjects
Publications and source records attributed to R M Harris-Warrick.
The cleavage of Bacillus subtilis DNA by EcoR1 restriction endonuclease produced segments which retain various degrees of genetic transforming activity. The active segments analyzed thus far, range in size from 23 to 3 kilobases and can be partially separated by agarose gel electrophoresis. Various markers can thus be enriched from 30- to 60-fold.
Ion channels and receptors play critical roles in shaping neuronal activity, and thus are appropriate targets for evolutionary change to generate new behaviors. In this review, the evolution and differentiation of the many voltage-gated ion channels and transmitter-activated receptors is summarized; these channels and receptors evolved very early, and with some exceptions all species with nervous systems use similar sets of channels and receptors. Several examples are given of mechanisms for species-specific behavioral evolution that arise from mutations involving the structure, alternative splicing, level of expression, targeting and modulation of these important neural proteins.
We consider whole-cell voltage-clamp data of isolated currents characterized by the Hodgkin-Huxley paradigm. We examine the errors associated with the typical parameter estimation method for these data and show them to be unsatisfactorally large especially if the time constants of activation and inactivation are not sufficiently separated. The size of these errors is due to the fact that the steady-state and kinetic properties of the current are estimated disjointly. We present an improved parameter estimation method that utilizes all of the information in the voltage-clamp conductance data to estimate steady-state and kinetic properties simultaneously and illustrate its success compared to the standard method using simulated data and data from P. interruptus shal channels expressed in oocytes.