MAP9/MAPH-9 supports axonemal microtubule doublets and modulates motor movement.

Microtubule doublets (MTDs) comprise an incomplete microtubule (B-tubule) attached to the side of a complete cylindrical microtubule. These compound microtubules are conserved in cilia across the tree of life; however, the mechanisms by which MTDs form and are maintained in vivo remain poorly understood. Here, we identify microtubule-associated protein 9 (MAP9) as an MTD-associated protein.

The connectome of an insect brain.

Brains contain networks of interconnected neurons and so knowing the network architecture is essential for understanding brain function. We therefore mapped the synaptic-resolution connectome of an entire insect brain ( larva) with rich behavior, including learning, value computation, and action selection, comprising 3016 neurons and 548,000 synapses. We characterized neuron types, hubs, feedforward and feedback pathways, as well as cross-hemisphere and brain-nerve cord interactions.

MAP9/MAPH-9 supports axonemal microtubule doublets and modulates motor movement.

Microtubule doublets (MTDs) are a well conserved compound microtubule structure found primarily in cilia. However, the mechanisms by which MTDs form and are maintained remain poorly understood. Here, we characterize microtubule-associated protein 9 (MAP9) as a novel MTD-associated protein.

Activation and expansion of presynaptic signaling foci drives presynaptic homeostatic plasticity.

Presynaptic homeostatic plasticity (PHP) adaptively regulates synaptic transmission in health and disease. Despite identification of numerous genes that are essential for PHP, we lack a dynamic framework to explain how PHP is initiated, potentiated, and limited to achieve precise control of vesicle fusion. Here, utilizing both mice and Drosophila, we demonstrate that PHP progresses through the assembly and physical expansion of presynaptic signaling foci where activated integrins biochemically converge with trans-synaptic Semaphorin2b/PlexinB signaling.