1. Department of Anatomy, Cell Biology, Physiology and Biophysics; Campinas State University; Campinas; São Paulo; 13084-864; Brazil
2. Laboratory of Microscopy and Microanalysis; Department of Biology; São Paulo State University; São José do Rio Preto; São Paulo; 15054-000; Brazil
3. Department of Morphology; Federal University of Goiás; Goiânia; Goiás; 74001-970; Brazil