The arthropod head problem has troubled scientists for more than a century. The segmental composition of the arthropod head, homology of its appendages, and especially the nature of the most anterior region of...
The forelimb of the flightless emu is a vestigial structure, with greatly reduced wing elements and digit loss. To explore the molecular and cellular mechanisms associated with the evolution of vestigial wings...
Authors: Craig A. Smith, Peter G. Farlie, Nadia M. Davidson, Kelly N. Roeszler, Claire Hirst, Alicia Oshlack and David M. Lambert
Kinorhynchs are ecdysozoan animals with a phylogenetic position close to priapulids and loriciferans. To understand the nature of segmentation within Kinorhyncha and to infer a probable ancestry of segmentatio...
Many insects host their obligate, maternally transmitted symbiotic bacteria in specialized cells called bacteriocytes. One of the best-studied insect nutritional endosymbioses is that of the aphid and its endo...
Authors: Hsiao-ling Lu, Chun-che Chang and Alex C. C. Wilson
Basic Helix-Loop-Helix (bHLH) genes encode a large family of eukaryotic transcription factors, categorized into six high-order groups: pan-eukaryotic group B involved in regulation of cell cycle, metabolism, a...
Authors: Sofia A. V. Fortunato, Michel Vervoort, Marcin Adamski and Maja Adamska
Gonads are specialized gamete-producing structures that, despite their functional importance, are generated by diverse mechanisms across groups of animals and can be among the most plastic organs of the body. ...
Authors: B. Duygu Özpolat, Emily S. Sloane, Eduardo E. Zattara and Alexandra E. Bely
Genomic analysis has upended chordate phylogeny, placing the tunicates as the sister group to the vertebrates. This taxonomic rearrangement raises questions about the emergence of a tunicate/vertebrate ancestor.
Authors: Fernando Segade, Christina Cota, Amber Famiglietti, Anna Cha and Brad Davidson
Annelida is a morphologically diverse animal group that exhibits a remarkable variety in nervous system architecture (e.g., number and location of longitudinal cords, architecture of the brain). Despite this h...
Authors: Alexandra Kerbl, José M. Martín-Durán, Katrine Worsaae and Andreas Hejnol
Here we present a report on Ctenopalooza: A meeting of ctenophorologists held at the Whitney Laboratory for Marine Bioscience in St. Augustine, FL, USA, on March 14–15, 2016. In this report, we provide a summa...
Authors: Joseph F. Ryan, Christine E. Schnitzler and Sidney L. Tamm
Dbx1 is a homeodomain transcription factor involved in neuronal fate specification belonging to a widely conserved family among bilaterians. In mammals, Dbx1 was proposed to act as a transcriptional repressor ...
Authors: Sonia Karaz, Maximilien Courgeon, Hélène Lepetit, Eugenia Bruno, Raimondo Pannone, Andrea Tarallo, France Thouzé, Pierre Kerner, Michel Vervoort, Frédéric Causeret, Alessandra Pierani and Giuseppe D’Onofrio
An essential developmental pathway in sexually reproducing animals is the specification of germ cells and the differentiation of mature gametes, sperm and oocytes. The “germline” genes vasa, nanos and piwi are...
Authors: Adam M. Reitzel, Kevin Pang and Mark Q. Martindale
Bocconia and Macleaya are the only genera of the poppy family (Papaveraceae) lacking petals; however, the developmental and genetic processes underlying such evolutionary shift have no...
Authors: Cristina Arango-Ocampo, Favio González, Juan Fernando Alzate and Natalia Pabón-Mora
Organisms develop and evolve in a modular fashion, but how individual modules interact with the environment remains poorly understood. Phenotypically plastic traits are often under selection, and studies are n...
Authors: Aabha I. Sharma, Katherine O. Yanes, Luyang Jin, Sarah L. Garvey, Sartu M. Taha and Yuichiro Suzuki
The evolution of animal segmentation is a major research focus within the field of evolutionary–developmental biology. Most studied segmented animals generate their segments in a repetitive, anterior-to-poster...
Authors: Renske M. A. Vroomans, Paulien Hogeweg and Kirsten H. W. J. ten Tusscher
The microvillus is a versatile organelle that serves important functions in disparate animal cell types. However, from a molecular perspective, the microvillus has been well studied in only a few, predominantl...
Authors: Jesús F. Peña, Alexandre Alié, Daniel J. Richter, Lingyu Wang, Noriko Funayama and Scott A. Nichols
New branches within the embryonic chicken lung form via apical constriction, in which epithelial cells in the primary bronchus become trapezoidal in shape. These branches form at precise locations along the pr...
Authors: Daniel Tzou, James W. Spurlin III, Amira L. Pavlovich, Carolyn R. Stewart, Jason P. Gleghorn and Celeste M. Nelson
The ancestral arthropod is believed to have had a clustered arrangement of ten Hox genes. Within arthropods, Hox gene mutations result in transformation of segment identities. Despite the fact that variation i...
Authors: Ryan M. Pace, Miodrag Grbić and Lisa M. Nagy
Platynereis and other polychaete annelids with homonomous segmentation are regarded to closely resemble ancestral forms of bilateria. The head region comprises the prostomium, the peri...
Authors: Jan Grimmel, Adriaan W. C. Dorresteijn and Andreas C. Fröbius
Germ cells are specified during early development and are responsible for generating gametes in the adult. After germ cells are specified, they typically migrate to a particular niche in the organism where the...
Authors: Adam D. Langenbacher and Anthony W. De Tomaso
Shifts in floral form across angiosperms, particularly from radially symmetrical to bilaterally symmetrical flowers, are often associated with shifts in speciation rates and changes in pollination syndrome. Gr...
Authors: Brent A. Berger, Veronica Thompson, Aedric Lim, Vincent Ricigliano and Dianella G. Howarth
Freshwater planarians are well known for their regenerative abilities. Less well known is how planarians maintain spatial patterning in long-lived adult animals or how they re-pattern tissues during regenerat...
Authors: Ko W. Currie, David D. R. Brown, Shujun Zhu, ChangJiang Xu, Veronique Voisin, Gary D. Bader and Bret J. Pearson
The aquiferous body plan of poriferans revolves around internal chambers comprised of choanocytes, a cell type structurally similar to choanoflagellates. These choanocyte chambers perform a range of physiologi...
Authors: Shunsuke Sogabe, Nagayasu Nakanishi and Bernard M. Degnan
The Neotropical frog genera Ceratophrys, Chacophrys and Lepidobatrachus form the monophyletic family Ceratophryidae. Although in- and out-group relationships are not fully resolved, the monophyly of the three ge...
Authors: Marissa Fabrezi, Silvia Inés Quinzio, Javier Goldberg, Julio César Cruz, Mariana Chuliver Pereyra and Richard J. Wassersug
The Hippo pathway regulates growth rate and organ size in fly and mouse, notably through control of cell proliferation. Molecular interactions at the heart of this pathway are known to have originated in the u...
Authors: Alicia Coste, Muriel Jager, Jean-Philippe Chambon and Michaël Manuel
Cichlid fishes from the Rift Lakes of East Africa have undergone the most spectacular adaptive radiations in vertebrate history. Eco-morphological adaptations in lakes Victoria, Malawi and Tanganyika have resu...
Authors: Pierre Le Pabic, W. James Cooper and Thomas F. Schilling
The evolutionary mechanisms involved in shaping complex gene regulatory networks (GRN) that encode for morphologically similar structures in distantly related animals remain elusive. In this context, echinoder...
Authors: David Viktor Dylus, Anna Czarkwiani, Josefine Stångberg, Olga Ortega-Martinez, Sam Dupont and Paola Oliveri
Obligate intracellular symbionts of insects are metabolically and developmentally integrated with their hosts. Typically, reproduction fails in many insect nutritional endosymbioses when host insects are cured...
Authors: Hsiao-ling Lu, Daniel R. G. Price, Athula Wikramanayake, Chun-che Chang and Alex C. C. Wilson
It has been hypothesized that the ParaHox gene Gsx patterned the foregut of the last common bilaterian ancestor. This notion was corroborated by Gsx expression in three out of four lophotrochozoan species, severa...
Authors: Tim Wollesen, Sonia Victoria Rodríguez Monje, Carmel McDougall, Bernard M. Degnan and Andreas Wanninger
Development of cerebral eyes is generally based on fine-tuned networks and closely intertwined with the formation of brain and head. Consistently and best studied in insects and vertebrates, many signaling pat...
Authors: Oliver Vöcking, Ioannis Kourtesis and Harald Hausen
Fish correspond to the most diversified phylum among vertebrates with a large variety of species. Even if general features are distinguishable during the embryogenesis, several differences in term of timing, o...
We analyze the interdisciplinary state of evolutionary developmental biology based on the diversity of themes, taxa, levels of organization and scientists at the first meeting of the Pan-American Society for E...
Wnt signaling pathways are highly conserved signal transduction pathways important for axis formation, cell fate specification, and organogenesis throughout metazoan development. Within the various Wnt pathway...
Authors: Benjamin R. Bastin, Hsien-Chao Chou, Margaret M. Pruitt and Stephan Q. Schneider
The origin of discrete novelties remains unclear. Some authors suggest that qualitative phenotypic changes may result from the reorganization of preexisting phenotypic traits during development (i.e., developm...
Authors: Sylvain Londe, Thibaud Monnin, Raphaël Cornette, Vincent Debat, Brian L. Fisher and Mathieu Molet
The variation in mandibular morphology of mammals reflects specialisations for different diets. Omnivorous and carnivorous mammals posses large mandibular coronoid processes, while herbivorous mammals have pro...
Authors: Neal Anthwal, Heiko Peters and Abigail S. Tucker
The evolution and development of sexual dimorphism illuminates a central question in biology: How do similar genomes produce different phenotypes? In an XX/XO system especially the state of a sexually dimorphi...
Authors: Andrea Sajuthi, Brenna Carrillo-Zazueta, Briana Hu, Anita Wang, Logan Brodnansky, John Mayberry and Ajna S. Rivera
The longstanding canonical model of spider gastrulation posits that cell internalization occurs only at a unitary central blastopore; and that the cumulus (dorsal organizer) arises from within the early deep l...
Authors: Allison Edgar, Christine Bates, Kay Larkin and Steven Black
Understanding how genes change during evolution to direct the development of diverse body plans is a major goal of the evo-devo field. Achieving this will require the establishment of new model systems that re...
Authors: Jie Xiang, Iain S. Forrest and Leslie Pick
Introns represent a potentially rich source of existing transcription for the evolution of novel microRNAs (miRNAs). Within the Hox gene clusters, a miRNA gene, miR-615, is located within the intron of the Hoxc5 ...
A notochord is characteristic of developing chordates (which comprise amphioxus, tunicates and vertebrates), and, more arguably, is also found in some other animals. Although notochords have been well reviewed...
Authors: Giovanni Annona, Nicholas D. Holland and Salvatore D’Aniello
In a recent study, we have demonstrated that amelotin (AMTN) gene structure and its expression during amelogenesis have changed during tetrapod evolution. Indeed, this gene is expressed throughout enamel matrix d...
The life cycle of many animals includes a larval stage, which has diversified into an astonishing variety of ecological strategies. The Nemertea is a group of spiralians that exhibits a broad diversity of larv...
Authors: José M. Martín-Durán, Bruno C. Vellutini and Andreas Hejnol
The developmental basis of craniofacial morphology hinges on interactions of numerous signalling systems. Extensive craniofacial variation in the polymorphic Arctic charr, a member of the salmonid family, from...
Authors: Ehsan Pashay Ahi, Sophie S. Steinhäuser, Arnar Pálsson, Sigrídur Rut Franzdóttir, Sigurdur S. Snorrason, Valerie H. Maier and Zophonías O. Jónsson
Maximally indirect development via a pilidium larva is unique to the pilidiophoran clade of phylum Nemertea. All other nemerteans have more or less direct development. The origin of pilidial development with d...
Authors: Laurel S Hiebert and Svetlana A Maslakova
A major goal of evolutionary biology is to understand the origins of phenotypic diversity. Changes in development, for instance heterochrony, can be a potent source of phenotypic variation. On the other hand, ...
Authors: Kara E. Powder, Kayla Milch, Garrett Asselin and R. Craig Albertson
Gastrulation is a critical step in bilaterian development, directly linked to the segregation of germ layers, establishment of axes, and emergence of the through-gut. Theories about the evolution of gastrulati...
Authors: Deirdre C. Lyons, Kimberly J. Perry and Jonathan Q. Henry
The metagenesis of sessile polyps into pelagic medusae in cnidarians represents one of the most ancient complex life cycles in animals. Interestingly, scyphozoans and hydrozoans generate medusae by apparently ...
Authors: Johanna E. M. Kraus, David Fredman, Wei Wang, Konstantin Khalturin and Ulrich Technau
Siphonophores (Hydrozoa) have unparalleled colony-level complexity, precision of colony organization, and functional specialization between zooids (i.e., the units that make up colonies). Previous work has sho...
Authors: Stefan Siebert, Freya E. Goetz, Samuel H. Church, Pathikrit Bhattacharyya, Felipe Zapata, Steven H.D. Haddock and Casey W. Dunn
Vertebrate somites are subdivided into lineage compartments, each with distinct cell fates and evolutionary histories. Insights into somite evolution can come from studying amphioxus, the best extant approxima...
Authors: Jennifer H Mansfield, Edward Haller, Nicholas D Holland and Ava E Brent
The evolutionary origins of cell polarity in metazoan embryos are unclear. In most bilaterian animals, embryonic and cell polarity are set up during embryogenesis with the same molecules being utilized to regu...
Authors: Miguel Salinas-Saavedra, Thomas Q Stephenson, Casey W Dunn and Mark Q Martindale
Most of our current findings on appendage formation and patterning stem from studies on chordate and ecdysozoan model organisms. However, in order to fully understand the evolution of animal appendages, it is ...
Authors: Marie-Therese Nödl, Sara M Fossati, Pedro Domingues, Francisco J Sánchez and Letizia Zullo
