44 research outputs found

    A Phylogenomic Analysis of the Floral Transcriptomes of Sexually Deceptive and Rewarding European Orchids, Ophrys and Gymnadenia.

    Get PDF
    The orchids (Orchidaceae) constitute one of the largest and most diverse families of flowering plants. They have evolved a great variety of adaptations to achieve pollination by a diverse group of pollinators. Many orchids reward their pollinators, typically with nectar, but the family is also well-known for employing deceptive pollination strategies in which there is no reward for the pollinator, in the most extreme case by mimicking sexual signals of pollinators. In the European flora, two examples of these different pollination strategies are the sexually deceptive genus Ophrys and the rewarding genus Gymnadenia, which differ in their level of pollinator specialization; Ophrys is typically pollinated by pseudo-copulation of males of a single insect species, whilst Gymnadenia attracts a broad range of floral visitors. Here, we present and describe the annotated floral transcriptome of Ophrys iricolor, an Andrena-pollinated representative of the genus Ophrys that is widespread throughout the Aegean. Furthermore, we present additional floral transcriptomes of both sexually deceptive and rewarding orchids, specifically the deceptive Ophrys insectifera, Ophrys aymoninii, and an updated floral transcriptome of Ophrys sphegodes, as well as the floral transcriptomes of the rewarding orchids Gymnadenia conopsea, Gymnadenia densiflora, Gymnadenia odoratissima, and Gymnadenia rhellicani (syn. Nigritella rhellicani). Comparisons of these novel floral transcriptomes reveal few annotation differences between deceptive and rewarding orchids. Since together, these transcriptomes provide a representative sample of the genus-wide taxonomic diversity within Ophrys and Gymnadenia (Orchidoideae: Orchidinae), we employ a phylogenomic approach to address open questions of phylogenetic relationships within the genera. Specifically, this includes the controversial placement of O. insectifera within the Ophrys phylogeny and the placement of "Nigritella"-type morphologies within the phylogeny of Gymnadenia. Whereas in Gymnadenia, several conflicting topologies are supported by a similar number of gene trees, a majority of Ophrys gene topologies clearly supports a placement of O. insectifera as sister to a clade containing O. sphegodes

    Emergence of a floral colour polymorphism by pollinator-mediated overdominance.

    Get PDF
    Maintenance of polymorphism by overdominance (heterozygote advantage) is a fundamental concept in evolutionary biology. In most examples known in nature, overdominance is a result of homozygotes suffering from deleterious effects. Here we show that overdominance maintains a non-deleterious polymorphism with black, red and white floral morphs in the Alpine orchid Gymnadenia rhellicani. Phenotypic, metabolomic and transcriptomic analyses reveal that the morphs differ solely in cyanidin pigments, which are linked to differential expression of an anthocyanidin synthase (ANS) gene. This expression difference is caused by a premature stop codon in an ANS-regulating R2R3-MYB transcription factor, which is heterozygous in the red colour morph. Furthermore, field observations show that bee and fly pollinators have opposite colour preferences; this results in higher fitness (seed set) of the heterozygous morph without deleterious effects in either homozygous morph. Together, these findings demonstrate that genuine overdominance exists in nature

    Demographic consequences of heterogeneity in conspecific density dependence among mast-fruiting tropical trees

    Get PDF
    The role of conspecific density dependence (CDD) in the maintenance of species richness is a central focus of tropical forest ecology. However, tests of CDD often ignore the integrated effects of CDD over multiple life stages and their long-term impacts on population demography. We combined a 10-year time series of seed production, seedling recruitment and sapling and tree demography of three dominant Southeast Asian tree species that adopt a mast-fruiting phenology. We used these data to construct individual- based models that examine the effects of CDD on population growth rates (ë) across life-history stages. Recruitment was driven by positive CDD for all species, supporting the predator satiation hypothesis, while negative CDD affected seedling and sapling growth of two species, significantly reducing ë. This negative CDD on juvenile growth overshadowed the positive CDD of recruitment, suggesting the cumulative effects of CDD during seedling and sapling development has greater importance than the positive CDD during infrequent masting events. Overall, CDD varied among positive, neutral and negative effects across life-history stages for all species, suggesting that assessments of CDD on transitions between just two stages (e.g. seeds seedlings or juveniles mature trees) probably misrepresent the importance of CDD on population growth and stability

    Insect-mediated microevolution of flowering plants

    Full text link

    In utero and postnatal imaging findings of parasitic conjoined twins (ischiopagus parasiticus tetrapus)

    Full text link
    Conjoined twins are a rare developmental anomaly with a reported prevalence of 1.47 per 100,000 births. We present an uncommon case of a parasitic ischiopagus tetrapus with a parasitic ischiopagus partial twin joined to the complete fetus at the level of the ischium diagnosed in utero by fetal MRI. The correct prenatal diagnosis led to birth by caesarean section. Prenatal MRI findings are presented and corroborated by postnatal imaging delineating the full extent and associated anomalies of this rare malformation. Differential diagnosis of duplicated lower extremities is discussed

    Data from: Herbivore-induced DNA demethylation changes floral signalling and attractiveness to pollinators in Brassica rapa

    No full text
    Plants have to fine-tune their signals to optimise the trade-off between herbivore deterrence and pollinator attraction. An important mechanism in mediating plant-insect interactions is the regulation of gene expression via DNA methylation. However, the effect of herbivore-induced DNA methylation changes on pollinator-relevant plant signalling has not been systematically investigated. Here, we assessed the impact of foliar herbivory on DNA methylation and floral traits in the model crop plant Brassica rapa. Methylation-sensitive amplified fragment length polymorphism (MSAP) analysis showed that leaf damage by the caterpillar Pieris brassicae was associated with genome-wide methylation changes in both leaves and flowers of B. rapa as well as a downturn in flower number, morphology and scent. A comparison to plants with jasmonic acid-induced defence showed similar demethylation patterns in leaves, but both the floral methylome and phenotype differed significantly from P. brassicae infested plants. Standardised genome-wide demethylation with 5-azacytidine in five different B. rapa full-sib groups further resulted in a genotype-specific downturn of floral morphology and scent, which significantly reduced the attractiveness of the plants to the pollinator bee Bombus terrestris. These results suggest that DNA methylation plays an important role in adjusting plant signalling in response to changing insect communities

    Trans-generational inheritance of herbivory-induced phenotypic changes in Brassica rapa

    Get PDF
    Biotic stress can induce plastic changes in fitness-relevant plant traits. Recently, it has been shown that such changes can be transmitted to subsequent generations. However, the occurrence and extent of transmission across different types of traits is still unexplored. Here, we assessed the emergence and transmission of herbivory-induced changes in Brassica rapa and their impact on interactions with insects. We analysed changes in morphology and reproductive traits as well as in flower and leaf volatile emission during two generations with leaf herbivory by Mamestra brassicae and Pieris brassicae and two subsequent generations without herbivory. Herbivory induced changes in all trait types, increasing attractiveness of the plants to the parasitoid wasp Cotesia glomerata and decreasing visitation by the pollinator Bombus terrestris, a potential trade-off. While changes in floral and leaf volatiles disappeared in the first generation after herbivory, some changes in morphology and reproductive traits were still measurable two generations after herbivory. However, neither parasitoids nor pollinators further discriminated between groups with different past treatments. Our results suggest that transmission of herbivore-induced changes occurs preferentially in resource-limited traits connected to plant growth and reproduction. The lack of alterations in plant-insect interactions was likely due to the transient nature of volatile changes

    Brassica rapa 5-azacytidine phenotype and assay

    No full text
    Phenotypic data (morphological traits and floral volatiles) and results of a two-choice assay with the pollinator Bombus terrestris of Brassica rapa rapid-cycling plants under 5-azacytidine treatment

    Herbivore-induced DNA demethylation changes floral signalling and attractiveness to pollinators in Brassica rapa

    Full text link
    Plants have to fine-tune their signals to optimise the trade-off between herbivore deterrence and pollinator attraction. An important mechanism in mediating plant-insect interactions is the regulation of gene expression via DNA methylation. However, the effect of herbivore-induced DNA methylation changes on pollinator-relevant plant signalling has not been systematically investigated. Here, we assessed the impact of foliar herbivory on DNA methylation and floral traits in the model crop plant Brassica rapa. Methylation-sensitive amplified fragment length polymorphism (MSAP) analysis showed that leaf damage by the caterpillar Pieris brassicae was associated with genome-wide methylation changes in both leaves and flowers of B. rapa as well as a downturn in flower number, morphology and scent. A comparison to plants with jasmonic acid-induced defence showed similar demethylation patterns in leaves, but both the floral methylome and phenotype differed significantly from P. brassicae infested plants. Standardised genome-wide demethylation with 5-azacytidine in five different B. rapa full-sib groups further resulted in a genotype-specific downturn of floral morphology and scent, which significantly reduced the attractiveness of the plants to the pollinator bee Bombus terrestris. These results suggest that DNA methylation plays an important role in adjusting plant signalling in response to changing insect communities

    Usability and validity of a novel smartphone application to measure shoulder range of motion

    No full text
    Shoulder mobility is an important clinical sign in the assessment of the shoulder joint. However, here is no gold standard measuring shoulder mobility in clinical practice. While some health care personnel use functional scales like the Constant-Murley, others use a portable goniometer, and scientists use advanced motion capture systems to measure the range of motion (ROM). Unfortunately, the Constant-Murley Scale tells nothing about the ROM as it analyses functional mobility. Although low-cost and quick to perform, a goniometer can only be used in the two dimensional area, needs trained personnel, and is related to a measurement error of 8°. Basically, visual estimation of the ROM results in the same error, but depends on the expertise of the examiner and the pain intensity of the patient. In contrast, advanced systems like X-ray machines, cinematography or Mocaps allow to analyse shoulder joint motion in the three dimensional area, resulting in a significantly smaller measurement error. However, they are time consuming, need highly trained personnel and an advanced laboratory equipment making them unsuitable for clinical use. A shoulder patient passes therefore several mobility measurement types in his course of therapy depending on the preference of his health care personnel. It would therefore be very attractive to have a low-cost, easy-to-use, three dimensional measuring device to asses shoulder mobility in applied settings. In addition, it would be very smart if anyone, even without preliminary knowledge in the field of shoulder measurements, could use this device intuitively. For this reason, smartphone applications (Apps) were developed. Since existing Apps need trained personnel, have no exercise instructions, or show incorrect measurements, the ZHAW developed a new therapy application (therapp®, available in German speaking AppStores®). The program uses the factory implemented gyroscope of the iPhone® to analyse three dimensional motions and shall allow the user to measure the own shoulder ROM without preliminary knowhow. The aim of the present study was to analyse usability of the App to identify barriers for successful application and to assess their importance regarding feasibility and ease of use. In addition, concurrent validity of therapp V-1.0.0 using an iPhone 4 versus a validated Mocap (Xsens® MVN Biomech Awinda) in an applied setting was analysed
    corecore