Biology subjects

Vincent, B. J.

Publications and source records attributed to Vincent, B. J..

5 recordsLinked to original sources

bioRxiv2025

Parallels in the Regulatory Landscape of Dimorphic Female and Male Genital Structures in Drosophila melanogaster

Understanding how morphological structures evolve via changes to their development is an ongoing pursuit in biology. Comparative approaches examine changes in the expression or function of key developmental molecules (e.g. transcription factors, signaling molecules or cellular effectors) within homologous structures, and correlate these changes with structural divergence across species, populations, the sexes, or even between different body parts within individuals. The female and male genitalia of Drosophila offer an excellent opportunity to investigate homology and trait evolution, as fruit fly genital structures are developmentally tractable and evolve rapidly. While previous work has characterized gene regulatory networks operating in the development and evolution of male genital structures in Drosophila, female pupal genitalia are comparatively understudied. Here, we traced the development of female pupal genitalia to determine when and how individual structures form. We then measured the expression patterns of 29 transcription factors in both female and male genital structures at high resolution using hybridization chain reaction and confocal microscopy. We found that these transcription factors are highly patterned in both sexes, and some serve as marker genes for distinct genital structures in females. Our results suggest that the same transcription factors may control developmental processes in female and male genitalia, and this data enables future studies that interrogate how developmental gene regulatory networks specialize and evolve in both sexes.

developmental biology↗

bioRxiv2021

Defining kinetic roles of transcriptional activators in the early Drosophila embryo

Most animal transcription factors are categorized as activators or repressors without specifying their mechanisms of action. Defining their specific roles is critical for deciphering the logic of transcriptional regulation and predicting the function of regulatory sequences. Here, we define the kinetic roles of three activating transcription factors in the Drosophila embryo--Zelda, Bicoid and Stat92E--by introducing their binding sites into the even skipped stripe 2 enhancer and measuring transcriptional output with live imaging. We find that these transcription factors act on different subsets of kinetic parameters, and these subsets can change over the course of nuclear cycle (NC) 14. These transcription factors all increase the fraction of active nuclei. Zelda dramatically shortens the time interval between the start of NC 14 and initial activation, and Stat92E increases the duration of active transcription intervals throughout NC 14. Zelda also decreases the time intervals between instances of active transcription early in NC 14, while Stat92E does so later. Different transcription factors therefore play distinct kinetic roles in activating transcription; this has consequences for understanding both regulatory DNA sequences as well as the biochemical function of transcription factors.

systems biology↗

bioRxiv2020

A mutation in the Drosophila melanogaster eve stripe 2 minimal enhancer is buffered by flanking sequences

Enhancers are DNA sequences composed of transcription factor binding sites that drive complex patterns of gene expression in space and time. Until recently, studying enhancers in their genomic context was technically challenging. Therefore, minimal enhancers, the shortest pieces of DNA that can drive an expression pattern that resembles a genes endogenous pattern, are often used to study features of enhancer function. However, evidence suggests that some enhancers require sequences outside the minimal enhancer to maintain function under environmental perturbations. We hypothesized that these additional sequences also prevent misexpression caused by a transcription factor binding site mutation within a minimal enhancer. Using the Drosophila melanogaster even-skipped stripe 2 enhancer as a case study, we tested the effect of a Giant binding site mutation (gt-2) on the expression patterns driven by minimal and extended enhancer reporter constructs. We found that, in contrast to the misexpression caused by the gt-2 binding site mutation in the minimal enhancer, the same gt-2 binding site mutation in the extended enhancer did not have an effect on expression. The buffering of expression levels, but not expression pattern, is partially explained by an additional Giant binding site outside the minimal enhancer. Mutating the gt-2 binding site in the endogenous locus had no significant effect on stripe 2 expression. Our results indicate that rules derived from mutating enhancer reporter constructs may not represent what occurs in the endogenous context.

genetics↗

bioRxiv2019

An atlas of transcription factors expressed in the Drosophila melanogaster pupal terminalia

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 Drosophila melanogaster and its close relatives exhibit dramatic changes in morphology between species. While previous studies have found network components important for patterning the larval genital disc, the networks governing adult structures during pupal development have remained uncharted. Here, we performed RNA-seq in whole Drosophila melanogaster terminalia followed by in situ hybridization for 100 highly expressed transcription factors during pupal development. We find that the terminalia is highly patterned during pupal stages and that specific transcription factors mark separate structures and substructures. Our results are housed online in a searchable database (flyterminalia.pitt.edu) where they can serve as a resource for the community. This work lays a foundation for future investigations into the gene regulatory networks governing the development and evolution of Drosophila terminalia.\n\nSummaryWe performed RNA-seq in whole Drosophila melanogaster terminalia (genitalia and analia) followed by in situ hybridization for 100 highly expressed transcription factors during pupal development. We find that the pupal terminalia is highly patterned with specific transcription factors marking separate structures and substructures. Our results are housed online in a searchable database (flyterminalia.pitt.edu) where they can serve as a resource for the community. This work lays a foundation for future investigations into the gene regulatory networks governing the development and evolution of Drosophila terminalia.

genetics↗

bioRxiv2017

Caudal counter-represses Hunchback to regulate even-skipped stripe 2 expression in Drosophila embryos

Hunchback is a bifunctional transcription factor that can activate and repress gene expression in Drosophila development. We investigated the regulatory DNA sequence features that control Hunchback function by perturbing enhancers for one of its target genes, even-skipped. While Hunchback directly represses the eve stripe 3+7 enhancer, we found that in the eve stripe 2+7 enhancer, Hunchback repression is prevented by Caudal binding--this relationship is called counter-repression. We found evidence that this relationship is conserved by comparing predicted binding sites for Hunchback and Caudal across orthologous eve stripe 2 enhancers. These results alter the textbook view of eve stripe 2 regulation wherein Hb is depicted as a direct activator. Instead, to generate stripe 2, Hunchback repression must be counteracted by Caudal binding. We discuss the implications of this interaction for eve stripe 2 regulation and evolution.

genetics↗