Genetic mechanisms of axial patterning in .

The genetic mechanisms underlying striking axial patterning changes in wild species are still largely unknown. Previous studies have shown that fish, commonly known as fourspine sticklebacks, have evolved multiple different axial patterns in wild populations. Here, we revisit classic locations in Nova Scotia, Canada, where both high-spined and low-spined morphs are particularly common.

Ancient developmental genes underlie evolutionary novelties in walking fish.

A critical question in biology is how new traits evolve, but studying this in wild animals remains challenging. Here, we probe the genetic basis of trait gain in sea robin fish, which have evolved specialized leg-like appendages for locomotion and digging along the ocean floor. We use genome sequencing, transcriptional profiling, and interspecific hybrid analysis to explore the molecular and developmental basis of leg formation.

Evolution of stickleback spines through independent cis-regulatory changes at HOXDB.

Understanding the mechanisms leading to new traits or additional features in organisms is a fundamental goal of evolutionary biology. We show that HOXDB regulatory changes have been used repeatedly in different fish genera to alter the length and number of the prominent dorsal spines used to classify stickleback species. In Gasterosteus aculeatus (typically 'three-spine sticklebacks'), a variant HOXDB allele is genetically linked to shortening an existing spine and adding an additional spine.

Mutations in RABL3 alter KRAS prenylation and are associated with hereditary pancreatic cancer.

Pancreatic ductal adenocarcinoma is an aggressive cancer with limited treatment options. Approximately 10% of cases exhibit familial predisposition, but causative genes are not known in most families. We perform whole-genome sequence analysis in a family with multiple cases of pancreatic ductal adenocarcinoma and identify a germline truncating mutation in the member of the RAS oncogene family-like 3 (RABL3) gene.

Efficient CRISPR-Cas9 editing of major evolutionary loci in sticklebacks.

Background: Stickleback fish are widely used to study the genetic and ecological basis of phenotypic evolution. Although several major loci have now been identified that contribute to evolutionary differences between wild populations, further study of the phenotypes associated with particular genes and mutations has been limited by the difficulty of generating targeted mutations at precise locations in the stickleback genome.

Approach And Aims: We compared different methods of expressing single-guide RNAs (sgRNAs) and Cas9 activity in fertilized stickleback eggs.