Microbial and chemical transformations of some 12,13-epoxytrichothec-9,10-enes.

Resting cells of Streptomyces griseus, Mucor mucedo, and a growing culture of Acinetobacter calcoaceticus when mixed with compounds related to 12,13-epoxytrichothec-9-ene-4beta,15-diacetoxy-3alpha-ol(anguidine) produced a series of derivatives that were either partially hydrolyzed or selectively acylated. These derivatives showed marked differences in activities as assayed by antifungal and tissue culture cytotoxicity tests.     

Production of 3-acetoxyscirpene-4,15-diol from anguidine (4,15-diacetoxyscirpene-3-ol) by Fusarium oxysporum f.sp. vasinfectum.

Growing cells of Fusarium oxysporum f.sp. vasinfectum (ATCC 7808) formed 3-acetoxyscirpene-4,15-diol from anguidine (4,15-diacetoxyscirpene-3-ol) by way of the intermediates triacetoxyscirpene, 3,4-diacetoxyscirpene-15-ol and 3,15-diacetoxyscirpene-4-ol. The new 3-acetoxy analog was found to be less active than anguidine and the other monoacetoxy derivatives when tested against a series of fungal strains and against HeLa cells in vitro.     

A further occurrence of Atherina boyeri Risso 1810 in North-Eastern Atlantic waters

Synopsis A further occurrence of Atherina boyeri in British waters is recorded. This species has a distribution which can be broadly defined as Mediterranean but has been occasionally recorded in waters which are beyond the northerly limits of its normal range. These records have usually been associated with localised thermal pollution but, at Oldbury-upon-Severn, England, this is probably not so. Morphometric and meristic data are presented which show clearly that this is a genuine record of A. boyeri. The existence of this species in waters with minimal, if any, thermal enrichment raises interesting questions regarding its distribution.This example and the other abnormal records of A. boyeri are, therefore, considered in relation to a number of environmental parameters. The parameters discussed, namely increased water temperature, decreased salinity and lagoon conditions have all been implicated in previous records.The conclusion tentatively reached is that A. boyeri is capable of surviving under a cooler temperature régime than that with which it is normally associated. Normally its range is restricted by inter-specific competition. In conditions of calmer water, however, in which there is also reduced salinity it is able to compete and maintain itself successfully.     

Deep mtDNA subdivision within Linnean species in an endemic radiation of tiger beetles from New Zealand (genus Neocicindela)

The invertebrate fauna of New Zealand is of great interest as a geologically tractable model for the study of species diversification, but direct comparisons with closely related lineages elsewhere are lacking. Integrating population-level analyses with studies of taxonomy and clade diversification, we performed mtDNA analysis on Neocicindela (Cicindelidae, tiger beetles) for a broad sample of populations from 11 of 12 known species and 161 specimens (three loci, 1883 nucleotides), revealing 123 distinct haplotypes. Phylogenetic reconstruction recovered two main lineages, each composed of 5-6 Linnean species whose origin was dated to 6.66 and 7.26 Mya, while the Neocicindela stem group was placed at 10.82 ± 0.48 Mya. Species delimitation implementing a character-based (diagnostic) species concept recognized 19 species-level groups that were in general agreement with Linnean species but split some of these into mostly allopatric subgroups. Tree-based methods of species delimitation using a mixed Yule-coalescence model were inconclusive, and recognized 32-51 entities (including singletons), splitting existing species into up to 8 partially sympatric groups. These findings were different from patterns in the Australian sister genus Rivacindela, where character-based and tree-based methods were previously shown to produce highly congruent groupings. In Neocicindela, the pattern of mtDNA variation was characterized by high intra-population and intra-species haplotype divergence, the coexistence of divergent haplotypes in sympatry, and a poor correlation of genetic and geographic distance. These observations combined suggest a scenario of phylogeographic divergence and secondary contact driven by orogenetic and climatic changes of the Pleistocene/Pliocene. The complex evolutionary history of most species of Neocicindela due to the relative instability of the New Zealand biota resulted in populations of mixed ancestry but not in a general loss of genetic variation.     

Oncopsis flavicollis (L.) associated with tree birches (Betula): a complex of biological species or a host plant utilization polymorphism?

The closely related species of leafhoppers, Oncopsis flavicollis (L.) and 0. subangulata (Sahl.), are restricted to birches, Betula pendula Roth and B. pubescens Ehrh., as host plants. Morphometric discriminant analyses of adult insects from S Wales showed O. flavicollis populations from the two Betula species to be significantly different. The best discrimination was provided by characters of the male dorsal abdominal apodemes. Analyses of such apodeme morphology in populations more widely from S Britain showed three distinct types: in western localities type 1 dominantly on B. pubescens , type 2 dominantly on B. pendula and type 3 absent; in eastern localities type 3 only on B. pendula , type 2 on both species of Betula and type 1 only on B. pubescens. Acoustic calling and courtship signals of males showed clear differences between the three apodeme types of 0. flavicollis. It is concluded that the three 0. flavicollis types, together with 0. subangulata , are distinct but very closely related biological species. Contrary to earlier suggestions, this example provides no evidence for host plant utilization polymorphisms.