Biology subjects

Eads, L.

Publications and source records attributed to Eads, L..

3 recordsLinked to original sources

bioRxiv2025

Cardiomyocyte-expressed TGFβ signals to fibroblasts to program early heart maturation and adult myocyte identity

Transforming growth factor {beta} (TGF{beta}) is a secreted growth factor that is sequestered to the extracellular matrix (ECM) as a latent complex. In adult disease TGF{beta} release in the heart transforms fibroblasts into a differentiated state that synthesizes more ECM. However, it is not known how TGF{beta} functions in the early developing heart to impact resident fibroblasts. Here, we observe that deletion of the Tgfb1, Tgfb2, and Tgfb3 genes (TGF{beta} ligands) from cardiomyocytes in the early developing heart results in cardiac dysfunction by 6 weeks of age with altered fibroblast activity and altered ECM content. Early postnatal hearts from Tgfb1/2/3 cardiomyocyte-deleted mice are dysmorphic and cardiac fibroblasts have incorrect activity and produce inappropriate ECM with reduced stiffness. Gene expression profiling of hearts from myocyte-specific Tgfb1/2/3 deleted mice reveal defects in both cardiomyocyte and fibroblast maturation with ectopic expression of multiple skeletal muscle-specific genes beginning at embryonic day 17.5 and progressing with age. However, cardiomyocyte-specific deletion of TGF{beta} receptors I/II encoding genes (Tgfbr1/2) or Smad2/3 encoding genes (Smad2/3) do not recapitulate this phenotype suggesting that TGF{beta} directly programs early heart fibroblast development that in turn specifies cardiomyocyte maturation. Importantly, Col1a2-/-;Col6a2-/- mice with defective cardiac ECM stiffness, mice lacking cardiomyocyte Itgb1 with reduced ECM load sensing, and Tcf21-/- embryos at E17.5 lacking cardiac fibroblasts each fail to generate the same pathologic ECM program with ectopic cardiomyocyte differentiation observed with Tgfb1/2/3 myocyte-specific deletion. These and additional results indicate that TGF{beta} generated by cardiomyocytes in the embryonic heart mediates fibroblast differentiation that co-evolves the ECM environment that in turn programs cardiomyocyte maturation to establish their identity.

developmental biology↗

bioRxiv2025

Genomics and reproductive biology of Leptopilina malgretoutensis Buffington, Lue, Davis & Tracey sp. nov. (Hymenoptera: Figitidae): An asexual parasitoid of Caribbean Drosophila

Drosophila and parasitic wasps in the genus Leptopilina have long been a model for understanding host-parasite interactions. Indeed, parasitic wasps are important drivers of ecological and evolutionary processes broadly, but we are generally lacking information about the diversity, natural history, and evolution of these relationships. We collected insects from the Caribbean Island of Saint Lucia, home to the eastern Caribbean dunni subgroup of Drosophila: a clade long appreciated for its recent patterns of speciation and adaptation. Here we present an integrative approach that incorporates natural history, taxonomy, physiology, and genomics to describe Leptopilina n. sp. Buffington, Lue, Davis & Tracey sp. nov. (Hymenoptera: Figitidae), a virulent parasitoid of dunni group flies, especially Drosophila antillea. Leptopilina n. sp. is nested within an early-branching clade of Leptopilina, offering insights into the evolution of this important genus of Drosophila parasitoids. We present a high-quality assembly for this wasps 1Gbp genome, and for its bacterial endosymbiont: Wolbachia strain "wLmal". Furthermore, we show that wLmal induces parthenogenesis in the wasp, and that these wasps are reliant upon their Wolbachia infections to produce female offspring. Finally, comparison to historical museum specimens indicate that Leptopilina n. sp. had been collected approximately 40 years prior from the nearby island of Guadeloupe and were also asexually reproducing. This work represents one of only a handful of studies in which field biology, taxonomy, systematics, genomics, and experimental biology are integrated into a species description: showcasing the possibilities for biodiversity research in the genomic era.

evolutionary biology↗

bioRxiv2023

A weaponized phage suppresses competitors in historical and modern metapopulations of pathogenic bacteria

Bacteriophages, the viruses of bacteria, are proposed to drive bacterial population dynamics, yet direct evidence of their impact on natural populations is limited. Here we identified viral sequences in a metapopulation of wild plant-associated Pseudomonas spp. genomes. We discovered that the most abundant viral cluster does not encode an intact phage but instead encodes a tailocin - a phage-derived element that bacteria use to kill competitors for interbacterial warfare. Each pathogenic Pseudomonas sp. strain carries one of a few distinct tailocin variants, which target variable polysaccharides in the outer membrane of co-occurring pathogenic strains. Analysis of historic herbarium samples from the last 170 years revealed that the same tailocin and receptor variants have persisted in the Pseudomonas populations for at least two centuries, suggesting the continued use of a defined set of tailocin haplotypes and receptors. These results indicate that tailocin genetic diversity can be mined to develop targeted "tailocin cocktails" for microbial control. One-Sentence SummaryBacterial pathogens in a host-associated metapopulation use a repurposed prophage to kill their competitors.

microbiology↗