Similar evolutionary potentials in an obligate ant parasite and its two host species.

The spatial structure of host-parasite coevolution is shaped by population structure and genetic diversity of the interacting species. We analysed these population genetic parameters in three related ant species: the parasitic slavemaking ant Protomognathus americanus and its two host species Temnothorax longispinosus and T. curvispinosus. We sampled throughout their range, genotyped ants on six to eight microsatellite loci and an MtDNA sequence and found high levels of genetic variation and strong population structure in all three species. Interestingly, the most abundant species and primary host, T. longispinosus, is characterized by less structure, but lower local genetic diversity. Generally, differences between the species were small, and we conclude that they have similar evolutionary potentials. The coevolutionary interaction between this social parasite and its hosts may therefore be less influenced by divergent evolutionary potentials, but rather by varying selection pressures. We employed different methods to quantify and compare genetic diversity and structure between species and genetic markers. We found that Jost D is well suited for these comparisons, as long as mutation rates between markers and species are similar. If this is not the case, for example, when using MtDNA and microsatellites to study sex-specific dispersal, model-based inference should be used instead of descriptive statistics (such as D or G(ST) ). Using coalescent-based methods, we indeed found that males disperse much more than females, but this sex bias in dispersal differed between species. The findings of the different approaches with regard to genetic diversity and structure were in good accordance with each other.

[Thalidomide therapy of cutaneous lupus erythematosus]. / Thalidomid-Therapie des kutanen Lupus erythematodes.

Immunosuppressive and immune-modulating substances such as corticosteroids, chloroquin, hydroxychloroquin, azathioprin, methotrexate, and others are standards in therapy of cutaneous lupus erythematosus. However, alternative substances are necessary when standard therapy regimens fail or are associated with side effects. Describing the course of disease in five female patients, we demonstrate alternative treatment of subacute cutaneous lupus erythematosus with thalidomide, showing good symptom response and possible side effects. By careful patient selection, we observed no polyneuropathy as it is most commonly described. In two cases, maculopapulous exanthema induced by medication was seen. The teratogeny of the substance must be taken into account in prescription. In selected cases, thalidomide can be a highly effective therapeutic option in the treatment of subacute cutaneous lupus erythematosus.