Biology subjects

Mandigo, T. R.

Publications and source records attributed to Mandigo, T. R..

5 recordsLinked to original sources

bioRxiv2025

Drosophila Modeling of Insomnia-Associated Genes Reveals Diverse Underlying Sleep Phenotypes

Insomnia is a prevalent sleep disorder with highly heterogenous manifestations. While data-driven approaches to insomnia subtyping have revealed potential differences between proposed insomnia subtypes and their impacts on overall health, little is known about the genetic factors that underly and differentiate these potential insomnia subtypes. We utilize a human-genetics driven approach to Drosophila modeling to identify the range of sleep traits regulated by insomnia-associated genes. Modeling pan-neuronal loss of Drosophila orthologs of a set of insomnia genes reveals a broad range of sleep phenotypes. Through systematic characterization of traits related to sleep quantity, timing, and quality, we identify genetic factors that co-regulate aspects of the insomnia-associated phenotypic landscape. Out of the 75 insomnia-associated genes identified, only 1/3 had at least one Drosophila ortholog that regulated overall sleep quantity. In contrast, 1/3 of the insomnia-associated genes had at least one Drosophila ortholog that regulated either sleep timing or sleep quality, without impacting sleep quantity. Together this work, in Drosophila, provides support for a genetic influence on the differences between insomnia subtypes.

neuroscience↗

bioRxiv2025

Drosophila Modeling Identifies Increased Sleep as a Link Between Insomnia and Cardiovascular Disease

Insomnia is a common sleep disorder associated with negative long-term health outcomes, including cardiovascular disease (CVD). We selected 16 genes from 13 insomnia- and CVD- associated genetic loci and disrupted Drosophila melanogaster orthologs in neuronal or cardiac tissue to characterize their roles in regulating sleep and cardiac physiology. Neuronal disruption of four orthologs (APOB, FUR, CYP17A1, and TCF4) resulted in short-sleeping flies, and three (MRAS, HDAC9, and TDRKH) resulted in long-sleeping flies. Short-sleeping fly lines impacted cardiac physiology consistent with links between short or poor-quality sleep and increased CVD in humans. Conversely, heart-specific disruption of five orthologs (RASD1, PHACTR1, CNNM2, MRAS, and TCF4) led to defects in cardiac physiology, with varied effects on sleep. Heart-specific knockdown lines that altered fractional shortening, a measure of cardiac contractility, also influenced long and short sleep states. These findings reveal bidirectional relationships between sleep states and cardiac performance, representing a potential feedback loop linking insomnia and CVD.

neuroscience↗

bioRxiv2024

Dystrophin interacts with Msp300 to Regulate Myonuclear Positioning and Microtubule Organization

During Drosophila myognesis, myonuclei are actively moved during embryogenesis, and their spacing is maintained through an anchoring mechanism in the fully differentiated myofiber. While we have identified microtubule associated proteins, motors, and nuclear envelope proteins that regulate myonuclear spacing, the developmental time during which each gene functions has not been tested. Here we have identified a Dystrophin as required only for the maintenance of myonuclear spacing. Furthermore, we demonstrate that Dystrophin genetically interacts with the KASH-domain protein Msp300 to maintain myonuclear spacing. Mechanistically, both Dystrophin and Msp300 regulate microtubule organization. Specifically, in animals with disrupted expression of both Dystrophin and Msp300, microtubule colocalization with sarcomeres is reduced. Taken altogether, these data indicate that the peripheral membrane protein Dystrophin, and the outer nuclear membrane protein Msp300, together regulate the organization of the microtubule network which then acts as an anchor to restrict myonuclear movement in contractile myofibers. These data are consistent with growing evidence that myonuclear movement and myonuclear spacing are critical to muscle development, muscle function, and muscle repair and provide a mechanism to connect disparate muscle diseases. Summary StatementHere we show that Dystrophin is required to maintain the spacing of nuclei in differentiated myofibers. Furthermore, Dystrophin achieves this function via a genetic interaction with Msp300 which regulates microtubule organization.

cell biology↗

bioRxiv2021

Synthetic lethal screening identifies existing drugs with selective viability effects on Neurofibromatosis type-1 model systems

Neurofibromatosis type 1 (NF1) is a genetic disorder associated with various symptoms including the formation of benign tumors along nerves. Drug treatments are currently limited. The MEK inhibitor selumetinib is used for a subset of cases but is not always effective and can cause side effects. Therefore, there is a clear need to discover new drugs to target NF1-deficient tumor cells. Using a Drosophila cell model of NF1, we performed synthetic lethal screens to identify novel drug targets. We identified 54 candidates, which were validated with variable dose analysis as a secondary screen. Five candidates could be targeted using existing drugs, with autophagy inhibitors (chloroquine (CQ) and bafilomycin A1) showing the greatest potential for selectively killing NF1-deficient Drosophila cells. When further investigating autophagy-related genes, we found that 14 out of 30 genes tested had a synthetic lethal interaction with NF1. These 14 genes are involved in the regulation of all aspects of the autophagy pathway and can be targeted with additional autophagy drugs, although none were as effective as CQ. The lethal effect of autophagy inhibitors was conserved in a panel of human NF1-deficient Schwann cell lines, highlighting their translational potential. The effect of CQ was also conserved in a Drosophila NF1 in vivo model and in a xenografted NF1-deficient tumor cell line in mice, with CQ treatment resulting in a more significant reduction in tumor growth than selumetinib treatment. Furthermore, combined treatment with CQ and selumetinib resulted in a further reduction in NF1-deficient cell viability. In conclusion, NF1-deficient cells are vulnerable to disruption of the autophagy pathway. This pathway represents a promising therapeutic target for NF1-associated tumors, and CQ was identified as a promising candidate drug for the treatment of NF1 tumors.

cancer biology↗

bioRxiv2020

The number of growing microtubules and nucleus-nucleus interactions uniquely regulate nuclear movement in Drosophila muscle

Nuclear movement is a fundamental process of eukaryotic cell biology. Skeletal muscle presents an intriguing model to study nuclear movement because its development requires the precise positioning of multiple nuclei within a single cytoplasm. Furthermore, there is a high correlation between aberrant nuclear positioning and poor muscle function. Although many genes that regulate nuclear movement have been identified, the mechanisms by which these genes act is not known. Using Drosophila melanogaster muscle development as a model system, and a combination of live-embryo microscopy and laser ablation of nuclei, we have found that phenotypically similar mutants are based in different molecular disruptions. Specifically, ensconsin (Drosophila MAP7) regulates the number of growing microtubules that are used to move nuclei whereas bocksbeutel (Drosophila emerin) and klarsicht (Drosophila KASH-protein regulate interactions between nuclei.

developmental biology↗