21 research outputs found

    A multilocus phylogeny of the world Sycoecinae fig wasps (Chalcidoidea: Pteromalidae)

    Get PDF
    The Sycoecinae is one of five chalcid subfamilies of fig wasps that are mostly dependent on Ficus inflorescences for reproduction. Here, we analysed two mitochondrial ( COI , Cyt b ) and four nuclear genes (ITS2, EF-1α, RpL27a, mago nashi ) from a worldwide sample of 56 sycoecine species. Various alignment and partitioning strategies were used to test the stability of major clades. All topologies estimated using maximum likelihood and Bayesian methods were similar and well resolved but did not support the existing classification. A high degree of morphological convergence was highlighted and several species appeared best described as species complexes. We therefore proposed a new classification for the subfamily. Our analyses revealed several cases of probable speciation on the same host trees (up to 8 closely related species on one single tree of F. sumatrana ), which raises the question of how resource partitioning occurs to avoid competitive exclusion. Comparisons of our results with fig phylogenies showed that, despite sycoecines being internally ovipositing wasps host-switches are common incidents in their evolutionary history. Finally, by studying the evolutionary properties of the markers we used and profiling their phylogenetic informativeness, we predicted their utility for resolving phylogenetic relationships of Chalcidoidea at various taxonomic levels

    TLR2 deficiency by compromising p19 (IL-23) expression limits T helper 17 cell responses to Mycobacterium tuberculosis

    Get PDF
    The authors are grateful to Drs. Manuel Teixeira da Silva, Fernando Rodrigues, Margarida Correia-Neves and Paul S. Redford for critically reading this manuscript and thank the personnel at the ICVS animal house facility for excellent animal husbandry.CD4+ Th1 cells producing IFN-γ are of extreme importance in controlling infections by Mycobacterium tuberculosis both in mice and in men. In addition to IFN-γ-producing T cells, IL-17-producing T cells (Th17) have been observed during mycobacterial infections. Nevertheless, their contribution for the host immune response to mycobacteria as well as the signals triggering M. tuberculosis -specific Th17 cell differentiation and maintenance are not fully understood. We show that signaling via Toll-like receptor (TLR) 2 has a major impact on the regulation of p19 (IL-23) expression in response to M. tuberculosis and therefore on the establishment of Th17 cell responses to M. tuberculosis infection. Diminished Th17 responses in the lung of M. tuberculosis -infected TLR2-deficient animals were not caused by defective cell differentiation in the draining lymph node (LN) but rather by reduced maintenance at the site of infection. Consistent with the decreased numbers of Th17 cells in the lungs of infected TLR2-deficient animals, we observed reduced expression of CXCL9, CXCL10 and CXCL11, chemokines involved in recall responses to M. tuberculosis. Our data provides insights into the TLR2 role in infection with M. tuberculosis, with implications in pathophysiology of the disease and vaccine design.Fundação para a Ciência e Tecnologia, Portugal (Project Grants PTDC/SAU/70895/2006 to AGC and PTDC/BIA-BCM/102776/2008 to MS; and Personal Grants SRFH/BD/33034/2006 to MTC; SFRH/BPD/3306/2007 to AC; SFRH/BD/35981/2007 to JC; SFRH/BI/33456/2008 to CS and PTDC/SAU-MII/70895/2006 to DRP) and by the Health Service of Fundação Calouste Gulbenkian. MS is a Ciência 2007 Fellow

    Phylogeny and codivergence in the fig-fig wasp mutualism : sycoecine and agaondid fig wasps (Chalcidoidea, Hymenoptera) associated with Ficus section Galoglychia (Moraceae)

    Get PDF
    Includes abstract.Includes bibliographical references.The interaction between figs and figs wasps is idealised as a classic example of coevolution through codivergence and cospeciation. Traditionally, the mutualism has been distinguished by a one-to-one ratio of host-specificity, whereby each species of fig tree (Ficlls, Moraceae) is pollinated by a unique species of fig wasp (Agaonidae, Chalcidoidea, Hymenoptera). Recent studies conclude, however, that extreme host-specificity is no longer as ubiquitous as previously considered. Nevertheless, there are many factors that are thought to constrain host-switching events and maintain, to some degree, the host specificity of both pollinating and non-pollinating fig wasps within the fig wasp community. This dissertation investigates the extent of codivergence between the host fig trees of Ficus section Galoglychia, associated agaonid pollinators and sycoecine non-pollinating fig wasps (Pteromalidae, Chalcidoidea, Hymenoptera) through cophylogenetic analysis

    Determinants of quality in a long-lived colonial species

    No full text
    1. In many animal populations a small proportion of individuals produce the majority of surviving offspring, but the underlying mechanisms are unclear. Behaviour may be an important determinant of variation in fitness: 'high-quality' individuals may have enhanced abilities in foraging or predator and parasite avoidance.2. The role of behaviour in determining variation in quality was examined using the common guillemot Uria aalge, a monogamous seabird with biparental care. Using a novel mixed model approach, we analysed binary data on breeding success of each pair attempting to breed in each year with variables critical to breeding success (timing of breeding; inferred age; breeding experience and success; number of nest sites and partners) as fixed effects. Random effects for year, male, female and each distinct pairing of a male and a female were included in the model, allowing a quality estimate to be derived for each individual and pair. A range of behaviours associated with breeding were examined in relation to these quality estimates.3. Breeding success declined with timing of breeding, and increased initially with age before declining in old age. It increased with previous successful experience, not breeding experience per se, until senescence effects became apparent. For males, breeding success declined with increasing numbers of mates.4. The most important behavioural determinants of quality operated at the level of the pair, with the time mates spent together at the site and chick feeding rates both positively related to quality. At the individual level, trip durations and feeding rates were associated with female but not male quality, suggesting that pair quality was operating principally through the female. However, removal of laying date, the most important component in the binomial model, confirmed that the pair effect was much larger than the female effect.5. This study demonstrates the potential of mixed modelling to determine quality estimates based on long-term breeding histories. The probability of a successful reproductive attempt was explained by the timing of breeding, age, successful breeding experience and number of mates. Behaviour was an important proximate mechanism underlying quality, in particular the foraging abilities of the pair, and the female's contribution to offspring provisioning. In species with biparental care, behavioural correlates of quality operate most strongly at the scale of the breeding pair, because contributions from both individuals are required for a successful outcome

    Phylogram of relationships among the Sycoecinae obtained from the analysis of the ClustalW alignment (combined dataset, without Gblocks cleaning, 5 partitions: mtDNA, <i>EF-1α</i>, ITS2, <i>RpL27a</i>, <i>mago</i><i>nashi</i>).

    No full text
    <p>Uppercase letters refer to clades discussed in the text. The new classification is indicated by colored bars on the right (yellow = oriental species, blue = afrotropical species). Nodes with likelihood bootstrap values < 70 have been collapsed. BP (> 70) and Bayesian posterior probabilities (> 0.90) are indicated at nodes. Illustrations of female habitus for the main clades are provided on the right. Host fig tree subsections are indicated between parentheses. Black boxes at nodes show cases of probable speciation on a single host <i>Ficus</i> species. </p

    Cladograms of relationships among the Sycoecinae obtained from the MAFFT alignment of the combined dataset under three different alignment strategies and two partitioning schemes.

    No full text
    <p>The corresponding ML and Bayesian trees are given in Figures 1, S7-S12. Nodes with BP support < 70% have been collapsed and BP supports for main clades are indicated at nodes. Uppercase letters refer to clades discussed in the text (see also Figure 1). The dashed line indicates the only taxon with a conflicting position among trees (see text).</p

    Phylogram of relationships among the Sycoecinae obtained from the analysis of the MAFFT alignment (combined dataset, without Gblocks cleaning, 6 partitions: mtDNAcodon1&2, mtDNAcodon3, <i>EF-1α</i>, ITS2, <i>RpL27a</i>, <i>mago</i><i>nashi</i>).

    No full text
    <p>Uppercase letters refer to clades discussed in the text. The new classification is indicated by colored bars on the right (yellow = oriental species, blue = afrotropical species). Nodes with likelihood bootstrap (BP) values < 70 have been collapsed. BP (> 70) and Bayesian posterior probabilities (> 0.90) are indicated at nodes. Illustrations of female habitus for the main clades are provided on the right. Host fig tree subsections are indicated between parentheses. Black boxes at nodes show cases of probable speciation on a single host <i>Ficus</i> species. </p

    Cladograms of relationships among the Sycoecinae obtained from the ClustalW alignment of the combined dataset under three different alignment strategies and two partitioning schemes.

    No full text
    <p>The corresponding ML and Bayesian trees are given in Figures 2, S1-S6. Nodes with BP support < 70% have been collapsed and BP supports for main clades are indicated at nodes. Uppercase letters refer to clades discussed in the text (see also Figure 2). The dashed line indicates the only taxon with a conflicting position among trees (see text).</p
    corecore