The next step in biology: A periodic table?

Systems biology is an approach to explain the behaviour of a system in relation to its individual components. Synthetic biology uses key hierarchical and modular concepts of systems biology to engineer novel biological systems. In my opinion the next step in biology is to use molecule-to-phenotype data using these approaches and integrate them in the form a periodic table. A periodic table in biology would provide chassis to classify, systematize and compare diversity of component properties vis-a-vis system behaviour. Using periodic table it could be possible to compute higher-level interactions from component properties. This paper examines the concept of building a bio-periodic table using protein fold as the fundamental unit.     

Formative effects of morphactin on the shoot apical meristem of flax (linum usitatissimum L.).

The effect of a morphactin -- CF1 -- (2-chloro-9-hydroxyfluorene-9-carbocylic acid-methyl ester) on the morphogenesis of shoot apical meristem was studied on L. usitatissimum L. at three levels of supply. CF1 at 10 and 100 parts/10(6) induced repeated gamophylly resembling a concentric cupulate structure. GA3 superimposed at two levels viz. 10 and 100 parts/10(6) did not reverse this effect. The effect of CF1 is dose-dependent and reversal to normal behaviour occurs when the effect of CF1 wears off.     

Contrasting effects of 5 alpha- and 5 beta-pregnane-3,20-dione on the motor activity of ovariectomized rats

While progesterone metabolites have long been known to be potent anesthetics in pharmacological doses, there is no available information as to their effects on behaviour at physiological levels. In this study, 5 alpha- and 5 beta-pregnanediones in silastic capsules were implanted in ovariectomized rats. Approximately 4 mg/kg/day was absorbed over a 24-day period. Rats receiving 5 beta-pregnanedione had decreased motor activity (58% control, P less than or equal to 0.001) while those receiving the 5 alpha-isomer had increased activity (143% control, P = 0.01). These studies suggest that these progesterone metabolites may be responsible for some behavioural changes.     

Action of histamine on the rapidly adapting airway receptors in the dog

The effects of histamine on the activity of rapidly adapting receptors (RAR) of the airways were investigated in anesthetized dogs. With bolus injections given into the right atrium, the threshold dose of histamine required for the excitation of RAR (n = 7) was 0.82 microgram/kg (+1.33/-0.51, geometric mean). With increasing doses of histamine, a dose-response relationship was seen in the activity of RAR. Obstruction of the lymphatic drainage from the lungs reduced the threshold dose to histamine (i.e., shifted the dose-response curve to the left significantly). This change in the dose-response relationship was not accompanied by a corresponding change in the relationship of histamine dose to airway pressures recorded before and after lymphatic obstruction. Against a background of pulmonary venous congestion produced by partial obstruction of the mitral valve, subthreshold doses of histamine stimulated the RAR (n = 4). The excitatory effect of histamine on RAR was found to be abolished by the administration of the H1 receptor antagonist diphenhydramine but not by the H2 receptor antagonist cimetidine. Intravenous infusion of histamine (0.4 microgram.kg-1.min-1) for a period of 10 min increased the RAR activity (n = 6) significantly without producing detectable changes in airway mechanics. The results indicate that contraction of the smooth muscle of the airways may not be a prerequisite for the excitation of RAR, especially at low doses. It is suggested that some of the effects of histamine on RAR are mediated by a local expansion of the extravascular fluid caused by an increase in the permeability of the bronchial vasculature.