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Full-Text Articles in Animal Sciences
Do Larval Traits Re-Evolve? Evidence From The Embryogenesis Of A Direct-Developing Salamander, Plethodon Cinereus, Ryan Kerney, David Blackburn, Hendrik Muller, James Hanken
Do Larval Traits Re-Evolve? Evidence From The Embryogenesis Of A Direct-Developing Salamander, Plethodon Cinereus, Ryan Kerney, David Blackburn, Hendrik Muller, James Hanken
Ryan Kerney
Recent molecular phylogenies suggest the surprising reacquisition of posthatching metamorphosis within an otherwise directdeveloping clade of lungless salamanders (family Plethodontidae). Metamorphosis was long regarded as plesiomorphic for plethodontids, yet the genus Desmognathus, which primarily includes metamorphosing species, is now nested within a much larger clade of direct-developing species. The extent to which the putative reacquisition of metamorphosis in Desmognathus represents a true evolutionary reversal is contingent upon the extent to which both larva-specific features and metamorphosis were actually lost during the evolution of direct development. In this study we analyze development of the hyobranchial skeleton, which is dramatically remodeled during …
Early Cranial Patterning In The Direct-Developing Frog Eleutherodactylus Coqui Revealed Through Gene Expression, Ryan Kerney, Joshua Gross, James Hanken
Early Cranial Patterning In The Direct-Developing Frog Eleutherodactylus Coqui Revealed Through Gene Expression, Ryan Kerney, Joshua Gross, James Hanken
Ryan Kerney
Genetic and developmental alterations associated with the evolution of amphibian direct development remain largely unexplored. Specifically, little is known of the underlying expression of skeletal regulatory genes, which may reveal early modifications to cranial ontogeny in direct-developing species. We describe expression patterns of three key skeletal regulators (runx2, sox9, and bmp4) along with the cartilage-dominant collagen 2a1 gene (col2a1) during cranial development in the direct- developing anuran, Eleutherodactylus coqui. Expression patterns of these regulators reveal transient skeletogenic anlagen that correspond to larval cartilages, but which never fully form in E. coqui. Suprarostral anlagen in the frontonasal processes are detected through …
Gene Expression Reveals Unique Skeletal Patterning In The Limb Of The Direct-Developing Frog, Eleutherodactylus Coqui, Ryan Kerney, James Hanken
Gene Expression Reveals Unique Skeletal Patterning In The Limb Of The Direct-Developing Frog, Eleutherodactylus Coqui, Ryan Kerney, James Hanken
Ryan Kerney
The growing field of skeletal developmental biology provides new molecular markers for the cellular pre- cursors of cartilage and bone. These markers enable resolution of early features of skeletal development that are otherwise undetectable through conventional staining tech- niques. This study investigates mRNA distributions of skeletal regulators runx2 and sox9 along with the cartilage-dominant collagen 2a1 (col2a1) in embryonic limbs of the direct- developing anuran, Eleutherodactylus coqui. To date, distri- butions of these genes in the limb have only been examined in studies of the two primary amniote models, mouse and chicken. In E. coqui, expression of transcription factors runx2 …