Place chicken breasts in slow cooker. In a medium mixing bowl, combine mushroom soup and Italian dressing mix; add sliced mushrooms and stir. Top chicken breasts with mushroom mixture. Cook on LOW for 6-7 hours. Cook spaghetti as directed on package. While spaghetti is cooking, shred chicken in slow cooker with two forks. Stir mixture. Serve over hot spaghetti.

Nutrition Information per serving (1 1/4 cup each):
416 Calories; 8g Fat (17.3%vcalories from fat); 37g Protein; 51g Carbohydrate; 6g Dietary Fiber; 67mg Cholesterol; 698mg Sodium.  Exchanges: 3 Grain(Starch); 3 1/2 Lean Meat; 1/2 Vegetable; 1 1/2 Fat; 0 Other Carbohydrates.