Co-option of the trichome-forming network initiated the evolution of a morphological novelty in Drosophila eugracilis.

Identifying the molecular origins by which new morphological structures evolve is one of the long-standing problems in evolutionary biology. To date, vanishingly few examples provide a compelling account of how new morphologies were initially formed, thereby limiting our understanding of how diverse forms of life derived their complex features. Here, we provide evidence that the large projections on the Drosophila eugracilis phallus that are implicated in sexual conflict have evolved through the partial co-option of the trichome genetic network.

Gene regulatory network co-option is sufficient to induce a morphological novelty in .

Identifying the molecular origins by which new morphological structures evolve is one of the long standing problems in evolutionary biology. To date, vanishingly few examples provide a compelling account of how new morphologies were initially formed, thereby limiting our understanding of how diverse forms of life derived their complex features. Here, we provide evidence that the large projections on the phallus that are implicated in sexual conflict have evolved through co-option of the trichome genetic network.

A developmental atlas of male terminalia across twelve species of .

How complex morphologies evolve is one of the central questions in evolutionary biology. Observing the morphogenetic events that occur during development provides a unique perspective on the origins and diversification of morphological novelty. One can trace the tissue of origin, emergence, and even regression of structures to resolve murky homology relationships between species.

TomoTwin: generalized 3D localization of macromolecules in cryo-electron tomograms with structural data mining.

Cryogenic-electron tomography enables the visualization of cellular environments in extreme detail, however, tools to analyze the full amount of information contained within these densely packed volumes are still needed. Detailed analysis of macromolecules through subtomogram averaging requires particles to first be localized within the tomogram volume, a task complicated by several factors including a low signal to noise ratio and crowding of the cellular space. Available methods for this task suffer either from being error prone or requiring manual annotation of training data.

A standardized nomenclature and atlas of the female terminalia of .

The model organism has become a focal system for investigations of rapidly evolving genital morphology as well as the development and functions of insect reproductive structures. To follow up on a previous paper outlining unifying terminology for the structures of the male terminalia in this species, we offer here a detailed description of the female terminalia of . Informative diagrams and micrographs are presented to provide a comprehensive overview of the external and internal reproductive structures of females.

Sex-specific evolution of a Drosophila sensory system via interacting cis- and trans-regulatory changes.

The evolution of gene expression via cis-regulatory changes is well established as a major driver of phenotypic evolution. However, relatively little is known about the influence of enhancer architecture and intergenic interactions on regulatory evolution. We address this question by examining chemosensory system evolution in Drosophila.

Resolving between novelty and homology in the rapidly evolving phallus of Drosophila.

The genitalia present some of the most rapidly evolving anatomical structures in the animal kingdom, possessing a variety of parts that can distinguish recently diverged species. In the Drosophila melanogaster group, the phallus is adorned with several processes, pointed outgrowths, that are similar in size and shape between species. However, the complex three-dimensional nature of the phallus can obscure the exact connection points of each process.

Co-evolving wing spots and mating displays are genetically separable traits in Drosophila.

The evolution of sexual traits often involves correlated changes in morphology and behavior. For example, in Drosophila, divergent mating displays are often accompanied by divergent pigment patterns. To better understand how such traits co-evolve, we investigated the genetic basis of correlated divergence in wing pigmentation and mating display between the sibling species Drosophila elegans and Drosophila gunungcola.

An Atlas of Transcription Factors Expressed in Male Pupal Terminalia of .

During development, transcription factors and signaling molecules govern gene regulatory networks to direct the formation of unique morphologies. As changes in gene regulatory networks are often implicated in morphological evolution, mapping transcription factor landscapes is important, especially in tissues that undergo rapid evolutionary change. The terminalia (genital and anal structures) of and its close relatives exhibit dramatic changes in morphology between species.

A standardized nomenclature and atlas of the male terminalia of .

Animal terminalia represent some of the most diverse and rapidly evolving structures in the animal kingdom, and for this reason have been a mainstay in the taxonomic description of species. The terminalia of , with its wide range of experimental tools, have recently become the focus of increased interest in the fields of development, evolution, and behavior. However, studies from different disciplines have often used discrepant terminologies for the same anatomical structures.

Modular tissue-specific regulation of underpins sexually dimorphic development in .

The ability of a single genome to produce distinct and often dramatically different male and female forms is one of the wonders of animal development. In , most sexually dimorphic traits are controlled by sex-specific isoforms of the () transcription factor, and expression is mostly limited to cells that give rise to sexually dimorphic traits. However, it is unknown how this mosaic of sexually dimorphic and monomorphic organs arises.

Rapid Evolution of Gained Essential Developmental Functions of a Young Gene via Interactions with Other Essential Genes.

New genes are of recent origin and only present in a subset of species in a phylogeny. Accumulated evidence suggests that new genes, like old genes that are conserved across species, can also take on important functions and be essential for the survival and reproductive success of organisms. Although there are detailed analyses of the mechanisms underlying new genes' gaining fertility functions, how new genes rapidly become essential for viability remains unclear.

Global Reduction of H3K4me3 Improves Chemotherapeutic Efficacy for Pediatric Ependymomas.

Background: Ependymomas (EPNs) are the third most common brain tumor in children. These tumors are resistant to available chemotherapeutic treatments, therefore new effective targeted therapeutics must be identified. Increasing evidence shows epigenetic alterations including histone posttranslational modifications (PTMs), are associated with malignancy, chemotherapeutic resistance and prognosis for pediatric EPNs.

Evolution: How Many Phenotypes Do Regulatory Mutations Affect?

Mutations in gene regulatory regions are thought to play an important role in the evolution of morphological structures. This is largely due to their minimal pleiotropic effects, limiting their impact to one particular body part. A recent study finds that one such regulatory mutation may affect two particular morphological structures.

Evolving doublesex expression correlates with the origin and diversification of male sexual ornaments in the Drosophila immigrans species group.

Male ornaments and other sex-specific traits present some of the most dramatic examples of evolutionary innovations. Comparative studies of similar but independently evolved traits are particularly important for identifying repeated patterns in the evolution of these traits. Male-specific modifications of the front legs have evolved repeatedly in Drosophilidae and other Diptera.

PI3K/AKT Pathway and Brain Malformations.

Investigators from Seattle Children's Research Institute, University of Washington, and collaborating institutions sought to evaluate 10 genes in the PI3K/AKT pathway as it relates epileptogenic brain malformations in patients with megalencephaly, hemimegalencephaly, and focal cortical dysplasia.

Effect of a refuge from persistent male courtship in the Drosophila laboratory environment.

The Drosophila melanogaster laboratory model has been used extensively in studies of sexual conflict because during the process of courtship and mating, males impose several costs upon females (e.g., reduced fecundity).