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.     

Purification and properties of a glucoamylase fraction from the culture filtrate of Rhizopus nodosus

A glucoamylase was isolated from the culture filtrate of Rhizopus nodosus and was separated from the acid lipase by DEAE-cellulose chromatography at pH 8.0 It was purified by Concanavalin A Sepharose 4B affinity chromatography followed by CM-Sephadex chromatography 387 fold with 30.7% yield. The homogeneity of the enzyme were confirmed by polyacrylamide gel electrophoresis and immunological studies. The different physico-chemical properties of the enzyme were studied. The molecular weight of the enzyme was found to be 71,000. Ethylenediaminetetraacetic acid had no effect on the enzyme whereas Hg2+ partially inhibited the enzyme activity. Tryptophan residues were found to be essential for the enzyme activity.     

Lignans of Piper clusii

From the petrol extract of Piper clusii five lignans were isolated. One of the lignans (?)-clusin is assigned the structure (?)-2-furanol-4(1,3-benzodioxol-5-ylmethyl) tetrahydro-3(3,4,5-trimethoxyphenyl) methyl. This is the first report of this compound from a natural source. Asaronaldehyde and sitosterol were also present.     

Molecular cloning and restriction enzyme analysis of a long repetitive DNA sequence in rice

Rice long repetitive DNA (9–20 kbp) reassociating at Cot 50 M.s was cloned in pBR325. Out of several recombinants (Cam^r Amp^r Tet^s), only a few were selected randomly for further characterization. The insert size in all these clones was 3–4 kbp. Restriction enzyme analysis showed the absence ofEcoRI andBclI sites, presence of a singlePstI andPvuII site and multiple sites forAluI in 3 clones namely pRLl, pRL7 and pRL10. TheBamHI-PstI fragment of about 0.4 kbp in the pRL7 insert DNA (pRL7-0.4 kbp) was subcloned in M13mpl8 and partially sequenced using Sanger’s dideoxynucleotide chain termination method. Dot matrix comparison of this sequence with rice rDNA sequences revealed low homology with the 25 S rDNA sequence of rice, however, hybridisation did not indicate any homology.     

A highly efficient in vitro regeneration methodology for mature Chinese tallow tree (Sapium sebiferum Roxb.)

A highly efficientin vitro regeneration methodology for mature chutese tallow tree (Sapium sebiferum Roxb.) has been developed. Shoot segments cultured on MS medium supplemented with 7.5 µM NAA produced light green callus. Optimum shoot differentiation resulted when callus was transferred to MS medium with 1 µM BA and 0.25 µM NAA. Shoot forming ability of callus was higher on MS medium compared to B5, half-MS or WPM. A continuous shoot harvest system at four-week intervals was established. Shoot yield continued for six months without loss of vigour. Regenerated shoots were rooted by culturing on half strength agar-gelled MS medium containing 1 µM IBA. Rooted plantlets were transferred to 1:1 soil vermiculite mixture and acclimatized with 67 % survival rate. Fully acclimatized plants were planted in the field, and performance is being evaluated.Abbreviations 2, 4- D 2, 4-dichlorophenoxyacetic acid - NAA 1 - napthaleneacetic acid - BA benzyladenine - Kn kinetin - 2-ip 6 - (, -dimethylallylamino)-purine - IBA indole-3-butyric acid - WPM woody plant medium (1980) - MS Murashige and Skoog (1962) medium - B5 Gamborg et al's medium (1968)     

Inhibition of seed germination by Macrophomina phaseolina is related to phaseolinone production

The production of phaseolinone, a phytotoxic metabolite of Macrophomina phaseolina in infected Phaseolus mungo seeds grown on soil, was estimated by enzyme-linked immunosorbent assay and HPLC. The degree of inhibition of seed germination correlated well with the amount of toxin produced; 50% inhibition was observed at a toxin level of 2.1 μg g^-1 of wet tissue. A comparison of the toxin-producing ability of nine isolates of the fungus obtained from different hosts and localities showed that the strain MPK'83 produced a significantly larger amount of the toxin, both in liquid culture and in infected seeds. The virulence of the isolates was related to their ability to produce phaseolinone.