Pluripotency of a founding field: rebranding developmental biology

The field of developmental biology has declined in prominence in recent decades, with off-shoots from the field becoming more fashionable and highly funded. This has created inequity in discovery and opportunity, partly due to the perception that the field is antiquated or not cutting edge. A 'think tank' of scientists from multiple developmental biology-related disciplines came together to define specific challenges in the field that may have inhibited innovation, and to provide tangible solutions to some of the issues facing developmental biology. The community suggestions include a call to the community to help 'rebrand' the field, alongside proposals for additional funding apparatuses, frameworks for interdisciplinary innovative collaborations, pedagogical access, improved science communication, increased diversity and inclusion, and equity of resources to provide maximal impact to the community.

Interactions between Twist and other core epithelial-mesenchymal transition factors are controlled by GSK3-mediated phosphorylation

A subset of transcription factors classified as neural crest 'specifiers' are also core epithelial-mesenchymal transition regulatory factors, both in the neural crest and in tumour progression. The bHLH factor Twist is among the least well studied of these factors. Here we demonstrate that Twist is required for cranial neural crest formation and fate determination in Xenopus. We further show that Twist function in the neural crest is dependent upon its carboxy-terminal WR domain. The WR domain mediates physical interactions between Twist and other core epithelial-mesenchymal transition factors, including Snail1 and Snail2, which are essential for proper function. Interaction with Snail1/2, and Twist function more generally, is regulated by GSK-3-β-mediated phosphorylation of conserved sites in the WR domain. Together, these findings elucidate a mechanism for coordinated control of a group of structurally diverse factors that function as a regulatory unit in both developmental and pathological epithelial-mesenchymal transitions.

SoxE Factors Function Equivalently during Neural Crest and Inner Ear Development and Their Activity Is Regulated by SUMOylation

Sox9 and the closely related factor Sox10 are essential for the formation of neural crest precursor cells, and play divergent roles in the process by which these cells are subsequently directed to form specific derivatives. These group E Sox factors have also been implicated in the development of the vertebrate inner ear. Despite their importance, however, the mechanisms that allow SoxE proteins to regulate such a diverse range of cell types have remained poorly understood. Here we demonstrate that during vertebrate development, the activities of individual SoxE factors are well conserved and are regulated by SUMOylation. We show that SoxE mutants that cannot be SUMOylated, or that mimic constitutive SUMOylation, are each able to mediate a subset of the diverse activities characteristic of wild-type SoxE proteins. These findings provide important mechanistic insight into how the activity of widely deployed developmental regulatory proteins can be directed to specific developmental events.

Serological determination of hepatitis C virus genotype: comparison with a standardized genotyping assay

In patients with chronic hepatitis C, determination of hepatitis C virus (HCV) genotype could be routinely run in the future to tailor treatment schedules. The suitabilities of two versions of a serological, so-called serotyping assay (Murex HCV Serotyping Assay version 1-3 [SA1-3] and Murex HCV Serotyping Assay version 1-6 [SA1-6]; Murex Diagnostics Ltd.), based on the detection of genotype-specific antibodies directed to epitopes encoded by the NS4 region of the genome, for the routine determination of HCV genotypes were studied. The results were compared with those of a molecular biology-based genotyping method (HCV Line Probe Assay [INNO-LiPA HCV]; Innogenetics S.A.), based on hybridization of PCR products onto genotype-specific probes designed in the 5' noncoding region of the genome, obtained with pretreatment serum samples from 88 patients with chronic hepatitis C eligible for interferon therapy. Definitive genotyping was performed by sequence analysis of three regions of the viral genome in all samples with discrepant typing results found among at least two of the three assays studied. In all instances, sequence analysis confirmed the result of the INNO-LiPA HCV test. The sensitivity of SA1-3 was 75% relative to the results obtained by the genotyping assay. The results were concordant with those of genotyping for 92% of the samples typeable by SA1-3. The sensitivity of SA1-6 was 89% relative to the results obtained by the genotyping assay. The results were concordant with those of genotyping for 94% of the samples typeable by SA1-6. Overall, SA1-6 had increased sensitivity relative to SA1-3 but remained less sensitive than the genotyping assay on the basis of PCR amplification of HCV RNA. Cross-reactivities between different HCV genotypes could be responsible for the mistyping of 8 (SA1-3) and 6% (SA1-6) of the samples. Subtyping of 1a and 1b is still not possible with the existing peptides, but discriminating between subtypes may not be necessary for routine use.