Biology subjects

Nechiporuk, A.

Publications and source records attributed to Nechiporuk, A..

3 recordsLinked to original sources

bioRxiv2026

Genetically interacting mutations and mechanical stress affect the stochasticity of developmental eye defects in yap1 mutants

Congenital abnormalities of eye formation show remarkably variable penetrance with phenotypes even varying between left and right eyes. Here we explore this phenomenon through analysis of the mechanistic basis of low penetrance retinal coloboma in zebrafish yap1nl13/nl13 mutants and identification of factors that modify the probability of this phenotype. We find that the low penetrance stochastically occurring coloboma in yap1nl13/nl13 mutants is due to rupture in the ventral retina at the point of apposition of the lips of the closing choroid fissure and that provision of wild-type Yap in the retinal pigment epithelium suppressed this phenotype. Decreasing actomyosin contractility increased the penetrance of coloboma whereas increasing myosin phosphorylation rescued the phenotype suggesting that altered mechanical properties of the RPE sensitize the eye to stochastic failure of choroid fissure closure. Genetic interaction screening revealed enhanced and synthetic eye phenotypes in yap1nl13/nl13mutants upon abrogation of function of genes encoding extracellular matrix and other genes implicated in eye formation. Our data reveal that the variable penetrance of congenital eye abnormalities can be due to genetic and environmental factors impacting the stochastic variability inherent in the developmental processes underlying eye morphogenesis.

developmental biology↗

bioRxiv2026

The Cxcl14 chemokine defines pioneer axon guidance and early circuit assembly in the inner ear

The nervous system wiring requires the precise coordination of axon guidance, neuronal migration, and target cell recognition. Here, we show that inner ear circuit formation, relies on pioneer cells extending an axonal scaffold that selectively target nascent hair cells. High spatiotemporal imaging of pioneer axons reveal how they navigate through the cranial environment, establish dynamic cell-cell contacts with other axons to finally stabilize in target cells. These pioneer axons are required not only for follower axon growth but also for coordinated migration of follower neurons, revealing a cellular hierarchy underlying circuit assembly. We identify the chemokine Cxcl14 as a novel instructive guidance cue regulating pioneer axon extension, turning, and fasciculation at discrete cellular decision points. Loss of Cxcl14 disrupts axonal navigation, compromises synaptic organization in hair cells, and impairs mechanosensory-based behavior. Together, our findings establish a new chemokine-based mechanism linking pioneer axon guidance to early sensory circuit assembly necessary for building mechanosensory networks.

developmental biology↗

bioRxiv2022

NudC regulated Lis1 stability is essential for maintenance of dynamic microtubule ends in the axon terminal

Axon terminal structure is critical for neuronal function. This cellular compartment houses synaptic terminals and is a site of high metabolic and functional demand. Axon terminals are also the site of a change in microtubule structure within the neuron. Microtubule stability is decreased relative to the axon shaft due to an enrichment of microtubule plus ends and increase in microtubule dynamics. These dynamic microtubule plus ends have many functions including serving as a docking site for the microtubule motor protein complex Cytoplasmic dynein. Here, we report an unexplored function of the dynein motor in axon terminals: regulation of microtubule stability. Using a forward genetic screen, we identified a mutant with abnormal axon terminal structure due to a loss of function mutation in the dynein interacting protein NudC. We show that the primary function of NudC in the axon terminal is as a chaperone for the protein Lis1. Loss of NudC results in decreased Lis1 protein in this neuronal compartment. Decreased Lis1 in nudc mutants causes dynein/dynactin accumulation and increased microtubule stability in axon terminals. Microtubules in the proximal axon are unaffected. Abnormal microtubule stability and structure can be suppressed by pharmacologically inhibiting dynein, implicating excess dynein motor activity as causal in the enhanced axon terminal microtubule stability. Together, our data support a model in which local NudC-Lis1 modulation of dynein motor activity is critical for regulation of microtubule stability in the axon terminal.

neuroscience↗