Preheat oven to 400°. Cook pasta according to package directions for al dente. Place squash in a large saucepan; add water to cover. Bring to a boil. Cook, covered, 8-10 minutes or until tender., Meanwhile, place yogurt, milk, salt, pepper and nutmeg in a blender. Drain squash and transfer to blender; cover and process until pureed. Return mixture to saucepan; heat through. Stir in cheeses until melted., Drain pasta; add to squash mixture. Toss to coat. Transfer to a greased 8-in. square baking dish. Sprinkle with bread crumbs., Bake, uncovered, until golden brown, 15-20 minutes.