Obligate mutualism within a host drives the extreme specialization of a fig wasp genome.

BACKGROUND: Fig pollinating wasps form obligate symbioses with their fig hosts. This mutualism arose approximately 75 million years ago. Unlike many other intimate symbioses, which involve vertical transmission of symbionts to host offspring, female fig wasps fly great distances to transfer horizontally between hosts. In contrast, male wasps are wingless and cannot disperse. Symbionts that keep intimate contact with their hosts often show genome reduction, but it is not clear if the wide dispersal of female fig wasps will counteract this general tendency. We sequenced the genome of the fig wasp Ceratosolen solmsi to address this question. RESULTS: The genome size of the fig wasp C. solmsi is typical of insects, but has undergone dramatic reductions of gene families involved in environmental sensing and detoxification. The streamlined chemosensory ability reflects the overwhelming importance of females finding trees of their only host species, Ficus hispida, during their fleeting adult lives. Despite long-distance dispersal, little need exists for detoxification or environmental protection because fig wasps spend nearly all of their lives inside a largely benign host. Analyses of transcriptomes in females and males at four key life stages reveal that the extreme anatomical sexual dimorphism of fig wasps may result from a strong bias in sex-differential gene expression. CONCLUSIONS: Our comparison of the C. solmsi genome with other insects provides new insights into the evolution of obligate mutualism. The draft genome of the fig wasp, and transcriptomic comparisons between both sexes at four different life stages, provide insights into the molecular basis for the extreme anatomical sexual dimorphism of this species.

Molecular approaches identify known species, reveal cryptic species and verify host specificity of Chinese Philotrypesis (Hymenoptera: Pteromalidae).

Philotrypesis, a major component of the fig wasp community (Hymenoptera: Pteromalidae), is a model taxon for studying male fighting and mating behaviour. Its extreme sexual dimorphism and male polymorphism render species identification uncertain and in-depth research on its ecology, behaviour and other evolutionary topics challenging. The fig wasps' enclosed habitat within the syconia makes their mating behaviour inaccessible, to the extent of matching conspecific females and males. In this study, we combine morphological and molecular analyses to identify species of Philotrypesis sampled from south China and to associate their extraordinarily dimorphic genders and labile male morphologies. Morphological evaluations of females identify 22 species and 28 male morphs. The mitochondrial cytochrome c oxidase I and nuclear internal transcribed spacer 2 data detect 21 species using females, and 15 species among the males. Most of the males match the species as delimited by females. Both markers reveal cryptic species in P. quadrisetosa on Ficus vasculosa. Most species of wasps live on one species of fig but three species co-occur in two hosts (F. microcarpa and F. benjamina), which indicates host switching.

Suppressed TGF-beta1 expression is correlated with up-regulation of matrix metalloproteinase-13 in keloid regression after flashlamp pulsed-dye laser treatment.

BACKGROUND AND OBJECTIVES: Flashlamp pulsed-dye lasers (PDLs) has shown effectiveness in the treatment of keloids. In this study, we investigated whether PDL treatments decreased transforming growth factor-beta1 (TGF-beta1)-induction and up-regulation of matrix metalloproteinase (MMP) expression in keloid regression. STUDY DESIGN/MATERIALS AND METHODS: Keloid tissues obtained from 10 patients with intra-lesional or punch biopsies before and 7 days after PDL treatments [fluence per pulse was 10-18 J/cm2 (mean 14.0 J/cm2)]. Immunohistochemical (IHC) staining of TGF-beta1 and MMP-1 and MMP-13 expressions in keloid tissue was performed. Western blot analysis of MMP-1 and MMP-13 expressions in extracellular matrix was evaluated. RESULTS: IHC staining indicated that expression of TGF-beta1 was significantly reduced in keloid tissues after PDL irradiation. MMP-13 but not MMP-1 expression on IHC staining significantly increased in extracellular matrix of keloid tissues after PDL treatment. Western blot analysis also showed MMP-13 but not MMP-1 significant increased in keloid tissues after PDL treatment. CONCLUSIONS: Regression of keloids regressed after PDL treatments are associated with down-regulation of TGF-beta1 expression and up-regulation of MMP-13 activity.