The Mating Type Locus (MAT) and Sexual Reproduction of Cryptococcus heveanensis: Insights into the Evolution of Sex and Sex-Determining Chromosomal Regions in Fungi

Mating in basidiomycetous fungi is often controlled by two unlinked, multiallelic loci encoding homeodomain transcription factors or pheromones/pheromone receptors. In contrast to this tetrapolar organization, Cryptococcus neoformans/Cryptococcus gattii have a bipolar mating system, and a single biallelic locus governs sexual reproduction. The C. neoformans MAT locus is unusually large (>100 kb), contains >20 genes, and enhances virulence. Previous comparative genomic studies provided insights into how this unusual MAT locus might have evolved involving gene acquisitions into two unlinked loci and fusion into one contiguous locus, converting an ancestral tetrapolar system to a bipolar one. Here we tested this model by studying Cryptococcus heveanensis, a sister species to the pathogenic Cryptococcus species complex. An extant sexual cycle was discovered; co-incubating fertile isolates results in the teleomorph (Kwoniella heveanensis) with dikaryotic hyphae, clamp connections, septate basidia, and basidiospores. To characterize the C. heveanensis MAT locus, a fosmid library was screened with C. neoformans/C. gattii MAT genes. Positive fosmids were sequenced and assembled to generate two large probably unlinked MAT gene clusters: one corresponding to the homeodomain locus and the other to the pheromone/receptor locus. Strikingly, two divergent homeodomain genes (SXI1, SXI2) are present, similar to the bE/bW Ustilago maydis paradigm, suggesting one or the other homeodomain gene was recently lost in C. neoformans/C. gattii. Sequencing MAT genes from other C. heveanensis isolates revealed a multiallelic homeodomain locus and at least a biallelic pheromone/receptor locus, similar to known tetrapolar species. Taken together, these studies reveal an extant C. heveanensis sexual cycle, define the structure of its MAT locus consistent with tetrapolar mating, and support the proposed evolutionary model for the bipolar Cryptococcus MAT locus revealing transitions in sexuality concomitant with emergence of a pathogenic clade. These studies provide insight into convergent processes that independently punctuated evolution of sex-determining loci and sex chromosomes in fungi, plants, and animals

Transcription Factors Mat2 and Znf2 Operate Cellular Circuits Orchestrating Opposite- and Same-Sex Mating in Cryptococcus neoformans

Cryptococcus neoformans is a human fungal pathogen that undergoes a dimorphic transition from a unicellular yeast to multicellular hyphae during opposite sex (mating) and unisexual reproduction (same-sex mating). Opposite- and same-sex mating are induced by similar environmental conditions and involve many shared components, including the conserved pheromone sensing Cpk1 MAPK signal transduction cascade that governs the dimorphic switch in C. neoformans. However, the homeodomain cell identity proteins Sxi1α/Sxi2a encoded by the mating type locus that are essential for completion of sexual reproduction following cell–cell fusion during opposite-sex mating are dispensable for same-sex mating. Therefore, identification of downstream targets of the Cpk1 MAPK pathway holds the key to understanding molecular mechanisms governing the two distinct developmental fates. Thus far, homology-based approaches failed to identify downstream transcription factors which may therefore be species-specific. Here, we applied insertional mutagenesis via Agrobacterium-mediated transformation and transcription analysis using whole genome microarrays to identify factors involved in C. neoformans differentiation. Two transcription factors, Mat2 and Znf2, were identified as key regulators of hyphal growth during same- and opposite-sex mating. Mat2 is an HMG domain factor, and Znf2 is a zinc finger protein; neither is encoded by the mating type locus. Genetic, phenotypic, and transcriptional analyses of Mat2 and Znf2 provide evidence that Mat2 is a downstream transcription factor of the Cpk1 MAPK pathway whereas Znf2 functions as a more terminal hyphal morphogenesis determinant. Although the components of the MAPK pathway including Mat2 are not required for virulence in animal models, Znf2, as a hyphal morphology determinant, is a negative regulator of virulence. Further characterization of these elements and their target circuits will reveal genes controlling biological processes central to fungal development and virulence

Hide your pain? The effects of social threat on pain reports, pain expression and pain-related fear

Pain is usually studied on an intrapersonal level, ignoring the social context in which it occurs. However, humans are social beings and concerning painful experiences the social environment has important effects on our behavior and experience. Research has shown that social factors have a profound influence on pain perception. For instance, when we are socially excluded, it hurts in a similar way as physical pain would. To date, very little research has systematically investigated how a threatening social context affects our pain perception and expression. Preliminary studies have shown that we try to conceal our pain by hiding bodily signals such as facial expressions. This might protect us from further threat, even though the pain we feel is actually worse. In this project we will investigate how social threat affects our pain perception and expression. First, we will investigate the effects of experiencing pain in a threatening social context. Second, we evaluate if predictable and unpredictable social threat differ in their effects. Third, we will evaluate how pain is perceived and expressed when someone else causes us pain. Finally, we will investigate the effects of social threat in bullying victims. An experimental paradigm and four experiments corresponding to these objectives are proposed. Since chronic pain patients often experience socially threatening situations, this research has implications for treatment and for the understanding of pain processing in general.status: publishe

Factor Structure, Reliability, and Known Groups Validity of the German Language version of the Childhood Trauma Questionnaire (Short-Form) in Swiss Patients and Non-Patients.

The Publisher's final version can be found by following the DOI link.he Childhood Trauma Questionnaire–Short Form is the most widely used instrument to assess childhood trauma and has been translated into 10 languages. However, research into validity and reliability of these translated versions is scarce. The present study aimed to investigate the factor structure, internal consistency, reliability, and known-groups validity of the German Childhood Trauma Questionnaire–Short Form (Bernstein & Fink, 1998). Six-hundred and sixty-one clinical and nonclinical participants completed the German Childhood Trauma Questionnaire–Short Form. A confirmatory factor analysis was conducted to assess the 5-factor structure of the original Childhood Trauma Questionnaire–Short Form. To investigate known-groups validity, the confirmatory factor analysis latent factor levels between clinical and nonclinical participants were compared. The original 5-factor structure was confirmed, with only the Physical Neglect scale showing rather poor fit. As a conclusion, the results support the validity and reliability of the German Childhood Trauma Questionnaire–Short Form. It is recommended to use the German Childhood Trauma Questionnaire–Short Form to assess experiences of childhood trauma

Factor structure, reliability, and known groups validity of the German version of the childhood trauma questionnaire (short-form) in Swiss patients and nonpatients

The Childhood Trauma Questionnaire-Short Form is the most widely used instrument to assess childhood trauma and has been translated into 10 languages. However, research into validity and reliability of these translated versions is scarce. The present study aimed to investigate the factor structure, internal consistency, reliability, and known-groups validity of the German Childhood Trauma Questionnaire-Short Form (Bernstein & Fink, 1998). Six-hundred and sixty-one clinical and nonclinical participants completed the German Childhood Trauma Questionnaire-Short Form. A confirmatory factor analysis was conducted to assess the 5-factor structure of the original Childhood Trauma Questionnaire-Short Form. To investigate known-groups validity, the confirmatory factor analysis latent factor levels between clinical and nonclinical participants were compared. The original 5-factor structure was confirmed, with only the Physical Neglect scale showing rather poor fit. As a conclusion, the results support the validity and reliability of the German Childhood Trauma Questionnaire-Short Form. It is recommended to use the German Childhood Trauma Questionnaire-Short Form to assess experiences of childhood trauma

Mothers' appraisals of injustice in the context of their child’s chronic pain: an interpretative phenomenological analysis

Background In line with research highlighting the role of observer appraisals in understanding individuals' pain experience, recent work has demonstrated the effects ofparental child- and self-oriented injustice appraisalson child pain-related outcomes. However, research on parental injustice appraisals is in its infancy and lacks a valid and context-specific operationalization of what parental injustice appraisals of child pain precisely entail. The current study presents an in-depth qualitative analysis of parental child- and self-oriented appraisals of injustice in the context of their child's chronic pain. Methods Twenty-one mothers of children living with chronic pain participated in one of five focus group interviews conducted in Ghent (Belgium), Glasgow (Scotland) and Indianapolis (USA). Results The interviews were subjected to interpretative phenomenological analysis, which revealed three key justice-related themes, labelled 'You shouldn't be in this much pain', 'The problem's probably with the mother' and 'At least it's not cancer'. Maternal injustice appraisals focused mainly on the child rather than the self and reflected various perceived barriers to their efforts to provide quality of life for their child. A fourth theme labelled 'Not everybody gets a healthy child' reflected maternal strategies to effectively cope with the child's condition and the associated appraisals of injustice. Conclusions The current findings attest to the relevance of (child- and self-oriented) injustice in the parental experience of caring for a child with chronic pain and provides insight into the specific content and scope of these appraisals. As such, this study provides valuable insights to further research in this area. Significance The current study presents an in-depth qualitative analysis of parental appraisals of injustice in the context of their child's chronic pain condition. The findings provide valuable insights into the phenomenology of this construct and may inform future research and assessment methods. Furthermore, the themes reported in this study may contribute to clinical practice, as they may raise awareness of parental concerns regarding their child's pain management