Characterization of nutrient status of Halamphora luciae (Bacillariophyceae) using matrix-assisted ultraviolet laser-desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS)

The effects of N and P depletion on the production and structural characterization of the cellular carbohydrate polymers of the estuarine diatom Halamphora luciae in batch culture were examined using matrix-assisted laser desorption-ionization time-of flight mass spectrometry (MALDI-TOF MS) complemented with monosaccharide composition determination and structural analyses by methylation of aqueous extracted product. The MALDI MS analysis of the cells showed a similar profile in control and N- and P-depleted media, with a displacement to higher molecular weight for cells grown in depleted media. In the monosaccharide analyses, both nutrient depletion and culture ageing led to an increase in glucose content, indicating that MALDI-TOF MS in whole cells was detecting the changes in chrysolaminarin. The maxima for the ions from f/2-P and to a lesser extent in f/2-N were displaced to higher m/z values indicating a higher degree of polymerization (DP). Methylation analysis confirmed the presence of chrysolaminarin, a (1→3)-β-d-glucan with branching in C2 and C6, where the glucan backbone had a substitution every four glucose residues. The (1→3)-β-d-glucan was also detected in the cingule by fluorescence with aniline blue.     

A myrionemoid variant of Ectocarpus fasciculatus Harv.

Culture experiments on Ectocarpus fasciculatus Harv. have been carried out using material from three separate localities. Under certain conditions, which have yet to be exactly defined, sporelings develop into plants quite unlike ‘normal’ Ectocarpus but resembling Myrionema corunnae Sauv. Reference is made to a field observation of a similar phenomenon by Jaasund (1965) and the status of M. corunnae is discussed.     

Development of microsatellite markers in the St Lucia anole, Anolis luciae

Anolis lizards are important models in studies of ecology and evolution. Here we describe 13 polymorphic microsatellites for use in population screening in the St Lucia anole, Anolis luciae, that can be used as a natural replicate to Anolis roquet on Martinique to study processes involved in population differentiation and speciation. Genotyping of 32 individuals using M13 tails and FAM-labelled universal M13 primers showed that all loci were polymorphic with high genetic diversity, averaging at 16.8 alleles per locus. Genotypic frequencies conformed to Hardy-Weinberg expectations, and there were no instances of linkage disequilibrium between loci.     

Cell-free polypeptide synthesis by crude extracts of the blue-green alga,Anacystis nidulans

Crude extracts of the blue-green alga, Anacystis nidulans Drouet (Kratz & Allen strain) are capable of supporting the incorporation of amino acids into polypeptide in the presence of an energy supply. Dialysis of the extracts stimulates incorporation while ribonuclease inhibits the process.