Each thin filament in the myofibril of a skeletal muscle fibre is made up of 

Each actin (thin) filament is made of two ‘F’ (filamentous) actins helically wound to each other. Each ‘F’ actin is a polymer of monomeric ‘G’ (Globular) actins. Two filaments of another protein, tropomyosin also run close to the ‘F’ actins throughout its length. A complex protein, troponin, is distributed at regular intervals on the tropomyosin. 

Meromyosin is present in the thick filament.