Cover image

Cover The pufferfish genome has evolved to be among the smallest of all vertebrates, and its morphological features are also greatly simplified. As this alcian-stained 22 day larva of the pufferfish Takifugu rubripes shows, skeletal reductions include the loss of ribs,the loss of the pelvic girdle and pelvic fins, and greatly modified cranial skeleton. What is the relationship of genome reduction and the developmental mechanisms leading to morphological simplification? A paper in this month's issue explores this question by investigating the structure and developmental roles of Hox cluster genes in pufferfish embryos. (For details, see Amores et al., pp. 1–10. Photograph by Tohru Suzuki.)