Seminarios del IBUNAM

In vertebrates, nature tends to favor symmetry of the craniofacial complex. The evolutionary pressures maintaining cranial symmetry highly variable across taxa, reflecting functional and morphological forces. The blind Mexican cavefish, which lives amidst total darkness, has evolved extensive cranial asymmetry in the bones encircling the eye. Our work reveals that as these bones grow, two novel ossification processes lead to asymmetric fragmentation in cavefish. Moreover, this asymmetry arises later in life, since juvenile cave and surface fish have symmetric skulls. Our studies are defining the transcriptomic, cellular and genetic bases of fragmentation to determine if there is adaptive significance of this cranial feature in cave-dwelling fish. Among vertebrates, this work will inform how intense environmental pressures shape unusual morphologies.