The mutation of CaCKI1 causes seedless fruits in chili pepper (Capsicum annuum).

KEY MESSAGE: The seedless mutant tn-1 in chili pepper is caused by a mutation in CaCKI1 (CA12g21620), which encodes histidine kinase involving female gametophyte development. An amino acid insertion in the receiver domain of CaCKI1 may be the mutation responsible for tn-1. Seedlessness is a desirable trait in fruit crops because the removal of seeds is a troublesome step for consumers and processing industries. However, little knowledge is available to develop seedless chili peppers. In a previous study, a chili pepper mutant tn-1, which stably produces seedless fruits, was isolated. In this study, we report characterization of tn-1 and identification of the causative gene. Although pollen germination was normal, confocal laser microscopy observations revealed deficiency in embryo sac development in tn-1. By marker analysis, the tn-1 locus was narrowed down to a 313 kb region on chromosome 12. Further analysis combined with mapping-by-sequencing identified CA12g21620, which encodes histidine kinase as a candidate gene. Phylogenetic analysis revealed CA12g21620 was the homolog of Arabidopsis CKI1 (Cytokinin Independent 1), which plays an important role in female gametophyte development, and CA12g21620 was designated as CaCKI1. Sequence analysis revealed that tn-1 has a 3-bp insertion in the 6th exon resulting in one lysine (K) residue insertion in receiver domain of CaCKI1, and the sequence nearby the insertion is widely conserved among CKI1 orthologs in various plants. This suggested that one K residue insertion may reduce the phosphorylation relay downstream of CaCKI1 and impair normal development of female gametophyte, resulting in seedless fruits production in tn-1. Furthermore, we demonstrated that virus-induced gene silencing of CaCKI1 reduced normally developed female gametophyte in chili pepper. This study describes the significant role of CaCKI1 in seed development in chili pepper and the possibility of developing seedless cultivars using its mutation.

Scale-dependent influences of environmental, historical, and spatial processes on taxonomic and functional beta diversity of Japanese bat assemblages.

This study investigated the relative influences of environmental, spatial, and historical factors, including the island-specific history of land connectivity, on bat assemblages in the Japanese Archipelago. We collected bat distribution data from 1408 studies and assigned them to Japan's First Standard Grid (approximately 6400 km2). Japanese bat assemblages were analyzed at two scales: the entire Japanese Archipelago comprised 16 islands and exclusively the four main islands. At first, we calculated taxonomic and functional total beta diversity (ß total) by Jaccard pairwise dissimilarity and then divided this into turnover (ß repl) and richness-difference (ß rich) components. We conducted hierarchical clustering of taxonomic beta diversity to examine the influence of the two representative sea straits, Tsugaru and Tokara, which are considered biogeographical borders. Variation partitioning was conducted to evaluate the relative effects of the three factors on the beta diversity. Clustering revealed that the Tokara Strait bordered the two major clades; however, the Tsugaru Strait did not act as a biogeographical border for bats. In the variation partitioning, shared fraction between spatial and historical factors significantly explained taxonomic and functional ß total and taxonomic ß repl at the entire archipelago scale, but not at the four main islands scale extending only Tsugaru Strait but not Tokara Strait. Pure environmental factors significantly explained functional ß total at both scales and taxonomic ß total only at the four main islands scale. These results suggest that spatial and historical factors are more pronounced in biogeographical borders, primarily structuring assemblage composition at the entire archipelago scale, especially in taxonomic dimension. However, current environmental factors primarily shape the assemblage composition of Japanese bats at the main island scale. The difference in results between the two scales highlights that the primary processes governing assemblages of both dimensions depend on the quality of the dispersal barriers between terrestrial and aquatic barriers for bats.

Polydipsia and autistic traits in patients with schizophrenia spectrum disorders.

Introduction: Polydipsia, prevalent in 6%-20% of patients with schizophrenia, results in seclusion and prolonged hospitalization. It is also observed in autistic individuals, with previous studies reporting that autism accounted for 20% of all hospitalized patients with polydipsia. The current study investigated the association between polydipsia and autistic traits in patients with schizophrenia spectrum disorders (SSDs) based on the hypothesis that higher autistic traits would be observed in schizophrenic patients with polydipsia. Methods: In the first study (study A), the autism-spectrum quotient [(AQ); Japanese version] scores of long-stay inpatients with and without polydipsia were compared. Furthermore, the association between polydipsia and autistic traits was also examined in short-stay inpatients and outpatients with SSDs (study B). Results: Study A showed that patients with polydipsia scored significantly higher on the three AQ subscales (attention switching; communication; and imagination) compared to those without. Study B also showed that patients with polydipsia had significantly higher AQ scores overall and for several subscales compared to those without polydipsia. Binary logistic regression analysis of the combined sample showed that male gender and higher autistic traits were significant predictors of polydipsia. Discussion: The study highlights the importance of focusing on such traits to understand the pathogenesis of polydipsia in SSD patients.

Association Between Autistic Symptoms and Self-Stigma in Patients with Schizophrenia Spectrum Disorders.

PURPOSE: Self-stigma negatively influences self-esteem, quality of life, self-efficacy, treatment adherence, and recovery in psychiatric patients. By revealing personality traits that influence self-stigma, we can gain useful knowledge for the management of self-stigma. A previous meta-analysis indicated that patients with schizophrenia have higher scores on the Autism-Spectrum Quotient (AQ) than healthy controls. However, the relationship between autistic symptoms and self-stigma in patients with schizophrenia spectrum disorders remains unclear. Therefore, the present study aimed to reveal the association between autistic symptoms and self-stigma in patients with schizophrenia spectrum disorders. PATIENTS AND METHODS: We recruited 127 patients with schizophrenia spectrum disorders (schizophrenia, schizoaffective disorder, and delusional disorder). We assessed participants' self-stigma and autistic symptoms using the Internalized Stigma for Mental Illness (ISMI) scale and the Autism-Spectrum Quotient (AQ), respectively. The differences in the scores of ISMI and AQ according to patient characteristics were investigated. Multiple regression analysis controlling for age and gender was performed to determine the relationship between the total scores on the AQ and IMSI scale. RESULTS: Female patients showed a higher level of self-stigma than males. Unmarried patients showed a significantly higher score on the AQ than married patients. Multiple regression analysis adjusted for age and gender indicated that the total score on AQ might be a predictor of the overall rating on ISMI in patients with schizophrenia spectrum disorders. CONCLUSION: This study is the first to reveal the association between autistic symptoms and self-stigma in patients with schizophrenia spectrum disorders. Our results highlight the importance of considering autistic symptoms in the assessment and management of self-stigma in patients with schizophrenia spectrum disorders.