Rad51 facilitates filament assembly of meiosis-specific Dmc1 recombinase.

Dmc1 recombinases are essential to homologous recombination in meiosis. Here, we studied the kinetics of the nucleoprotein filament assembly of Saccharomyces cerevisiae Dmc1 using single-molecule tethered particle motion experiments and in vitro biochemical assay. ScDmc1 nucleoprotein filaments are less stable than the ScRad51 ones because of the kinetically much reduced nucleation step. The lower nucleation rate of ScDmc1 results from its lower single-stranded DNA (ssDNA) affinity, compared to that of ScRad51. Surprisingly, ScDmc1 nucleates mostly on the DNA structure containing the single-stranded and duplex DNA junction with the allowed extension in the 5'-to-3' polarity, while ScRad51 nucleation depends strongly on ssDNA lengths. This nucleation preference is also conserved for mammalian RAD51 and DMC1. In addition, ScDmc1 nucleation can be stimulated by short ScRad51 patches, but not by EcRecA ones. Pull-down experiments also confirm the physical interactions of ScDmc1 with ScRad51 in solution, but not with EcRecA. Our results are consistent with a model that Dmc1 nucleation can be facilitated by a structural component (such as DNA junction and protein-protein interaction) and DNA polarity. They provide direct evidence of how Rad51 is required for meiotic recombination and highlight a regulation strategy in Dmc1 nucleoprotein filament assembly.

Taiwanese Dermatological Association (TDA) consensus recommendations for the definition, classification, diagnosis, and management of hidradenitis suppurativa.

Hidradenitis suppurativa (HS) is a chronic inflammatory follicular disease characterized by painful, recurrent, inflamed lesions most commonly occurring in the axillary, inguinal, and anogenital regions. HS can inflict immense physical and psychological impact on patients who suffer from this distressing disease. Management of HS generally requires combining various medical and procedural treatment modalities; however, the disease is often recalcitrant to conventional treatments. In light of recent evidence supporting the effectiveness of biologic agents in the treatment of HS, the Taiwanese Dermatological Association established an expert panel of nine dermatologists to develop consensus statements aimed to provide up-to-date evidence-based guidance in optimizing HS patient management in Taiwan. The recommendations described in the statements were summarized in a management algorithm in terms of general care, topical treatment, systemic treatment, and procedural treatment.

Female Pattern Hair Loss: An Overview with Focus on the Genetics.

Pattern hair loss can occur in both men and women, and the underlying molecular mechanisms have been continuously studied in recent years. Male androgenetic alopecia (M-AGA), also termed male pattern hair loss, is the most common type of hair loss in men. M-AGA is considered an androgen-dependent trait with a background of genetic predisposition. The interplay between genetic and non-genetic factors leads to the phenotype of follicular miniaturization. Although this similar pattern of phenotypic miniaturization can also be found in female pattern hair loss (FPHL), the corresponding genetic factors in M-AGA do not account for the phenotype in FPHL, indicating that there are different genes contributing to FPHL. Therefore, the role of genetic factors in FPHL is still uncertain. Understanding the genetic mechanism that causes FPHL is crucial for the future development of personalized treatment strategies. This review aims to highlight the differences in the ethnic prevalence and genetic background of FPHL, as well as the current genetic research progress in nutrition, Wnt signaling, and sex hormones related to FPHL.