Transcription factors that determine retinal development seem to be conserved in different phyla throughout the animal kingdom. In most representatives, however, only a few of the involved transcription factor...
Authors: Leyli Samadi, Axel Schmid and Bo Joakim Eriksson
Two visual systems are present in most arthropod groups: median and lateral eyes. Most of our current knowledge about the developmental and molecular mechanisms involved in eye formation in arthropods comes fr...
Authors: Christoph Schomburg, Natascha Turetzek, Magdalena Ines Schacht, Julia Schneider, Phillipp Kirfel, Nikola-Michael Prpic and Nico Posnien
How adaptive phenotypes are shaped by the action of key developmental genes during ontogeny remains poorly understood. Water striders, a group of hemipteran insects, present a unique example of adaptation to l...
The tardigrades (water bears) are a cosmopolitan group of microscopic ecdysozoans found in a variety of aquatic and temporarily wet environments. They are members of the Panarthropoda (Tardigrada + Onychophora...
The molecular mechanisms underlying sex determination and differentiation in animals are incredibly diverse. The Dmrt (doublesex and mab-3 related transcription factor) gene family is an evolutionary ancient grou...
Authors: Nikki G Traylor-Knowles, Eric G Kane, Vanna Sombatsaphay, John R Finnerty and Adam M Reitzel
Simple life cycles arise from complex life cycles when one or more developmental stages are lost. This raises a fundamental question - how can an intermediate stage, such as a larva, be removed, and developmen...
Authors: Rebecca R Helm, Stefano Tiozzo, Martin K S Lilley, Fabien Lombard and Casey W Dunn
Brachiopods undergo radial cleavage, which is distinct from the stereotyped development of closely related spiralian taxa. The mesoderm has been inferred to derive from the archenteron walls following gastrula...
Authors: Yale J Passamaneck, Andreas Hejnol and Mark Q Martindale
The urodele amphibians (salamanders) are the only adult tetrapods able to regenerate the limb. It is unclear if this is an ancestral property that is retained in salamanders but lost in other tetrapods or if i...
Authors: Jie Geng, Phillip B Gates, Anoop Kumar, Stefan Guenther, Acely Garza-Garcia, Carsten Kuenne, Peng Zhang, Mario Looso and Jeremy P Brockes
The limb and autopodium are frequently employed to study pattern formation during embryonic development, providing insights into how cells give rise to complex anatomical structures. With regard to the differe...
Authors: Eraqi R Khannoon, Anthony P Russell and Abigail S Tucker
The ABC model of flower development describes the molecular basis for specification of floral organ identity in model eudicots such as Arabidopsis and Antirrhinum. According to this model, expression of C-class g...
Authors: Ana Maria R Almeida, Roxana Yockteng, Wagner C Otoni and Chelsea D Specht
The bat has strikingly divergent forelimbs (long digits supporting wing membranes) and hindlimbs (short, typically free digits) due to the distinct requirements of both aerial and terrestrial locomotion. Durin...
Authors: Mandy K Mason, Dorit Hockman, Lyle Curry, Thomas J Cunningham, Gregg Duester, Malcolm Logan, David S Jacobs and Nicola Illing
Within Malacostraca (Crustacea), direct development and development through diverse forms of larvae are found. Recent investigations suggest that larva-related developmental features have undergone heterochron...
Authors: Günther Joseph Jirikowski, Carsten Wolff and Stefan Richter
Nodal is an important determinant of the left-right (LR) body axis in bilaterians, specifying the right side in protostomes and non-chordate deuterostomes as opposed to the left side in chordates. Amphioxus re...
Authors: Vladimir Soukup, Luok Wen Yong, Tsai-Ming Lu, Song-Wei Huang, Zbynek Kozmik and Jr-Kai Yu
The form that an animal takes during development is directed by gene regulatory networks (GRNs). Developmental GRNs interpret maternally deposited molecules and externally supplied signals to direct cell-fate ...
Authors: Alys M Cheatle Jarvela and Veronica F Hinman
The cellular signaling mechanisms and morphogenic movements involved in axis formation and gastrulation are well conserved between vertebrates. In nearly all described fish, gastrulation and the initial patter...
Ctenophores have traditionally been treated as eumetazoans, but some recent whole genome studies have revived the idea that they are, rather, the sister group to all other metazoans. This deep branching positi...
Authors: Gáspár Jékely, Jordi Paps and Claus Nielsen
The Solenogastres (or Neomeniomorpha) are a taxon of aplacophoran molluscs with contentious phylogenetic placement. Since available developmental data on non-conchiferan (that is, aculiferan) molluscs mainly s...
Authors: Emanuel Redl, Maik Scherholz, Christiane Todt, Tim Wollesen and Andreas Wanninger
The independent origin and evolution of leaves as small, simple microphylls or larger, more complex megaphylls in plants has shaped and influenced the natural composition of the environment. Significant contri...
Seahorses are well known for their highly derived head shape, prehensile tail and armoured body. They belong to the family of teleosts known as Syngnathidae, which also includes the pipefishes, pipehorses and ...
Authors: Tamara Anne Franz-Odendaal and Dominique Adriaens
Two issues relating to the translocation of anterior Hox genes in echinoderms to the 5’ end of the Hox cluster are discussed: i) that developmental changes associated with fixation to the substratum have led to a...
Hox genes are master regulatory genes that specify positional identities during axial development in animals. Discoveries regarding their concerted expression patterns have commanded intense interest due to th...
Authors: Sophie Archambeault, Julia Ann Taylor and Karen D Crow
Developmental biology, as all experimental science, is empowered by technological advances. The availability of genetic tools in some species - designated as model organisms - has driven their use as major pla...
Lepidium sisymbrioides, a polyploid New Zealand endemic, is the sole dioecious species in Brassicaceae and therefore the closest dioecious relative of the model plant Arabidopsis thaliana. The attractiveness of d...
Authors: Valerie L Soza, Vietnam Le Huynh and Verónica S Di Stilio
Among the Lophotrochozoa, cephalopods possess the highest degree of central nervous system (CNS) centralization and complexity. Although the anatomy of the developing cephalopod CNS has been investigated, the ...
Authors: Tim Wollesen, Carmel McDougall, Bernard M Degnan and Andreas Wanninger
Understanding the molecular basis of craniofacial variation can provide insights into key developmental mechanisms of adaptive changes and their role in trophic divergence and speciation. Arctic charr (Salvelinus...
Authors: Ehsan Pashay Ahi, Kalina Hristova Kapralova, Arnar Pálsson, Valerie Helene Maier, Jóhannes Gudbrandsson, Sigurdur S Snorrason, Zophonías O Jónsson and Sigrídur Rut Franzdóttir
Metazoan digestive systems develop from derivatives of ectoderm, endoderm and mesoderm, and vary in the relative contribution of each germ layer across taxa and between gut regions. In a small number of well-s...
Authors: Michael J Boyle, Emi Yamaguchi and Elaine C Seaver
Insect embryonic dorso-ventral patterning depends greatly on two pathways: the Toll pathway and the Bone Morphogenetic Protein pathway. While the relative contribution of each pathway has been investigated in ...
Authors: Mateus Berni, Marcio Ribeiro Fontenele, Vitoria Tobias-Santos, Aline Caceres-Rodrigues, Flavia Borges Mury, Raquel Vionette-do-Amaral, Hatisaburo Masuda, Marcos Sorgine, Rodrigo Nunes da Fonseca and Helena Araujo
Proseriates (Proseriata, Platyhelminthes) are free-living, mostly marine, flatworms measuring at most a few millimetres. In common with many flatworms, they are known to be capable of regeneration; however, fe...
Authors: Johannes Girstmair, Raimund Schnegg, Maximilian J Telford and Bernhard Egger
Although chordates descend from a segmented ancestor, the evolution of head segmentation has been very controversial for over 150 years. Chordates generally possess a segmented pharynx, but even though anatomi...
Authors: Demian Koop, Jie Chen, Maria Theodosiou, João E Carvalho, Susana Alvarez, Angel R de Lera, Linda Z Holland and Michael Schubert
Enhanced food-finding efficiency is an obvious adaptive response to cave environments. Here, we have compared the food-finding abilities of Astyanax surface fish and blind cavefish young larvae in their first mon...
Authors: Luis Espinasa, Jonathan Bibliowicz, William R Jeffery and Sylvie Rétaux
Multicellularity provides organisms with opportunities for cell-type specialization, but requires novel mechanisms to position correct proportions of different cell types throughout the organism. Dictyostelid ...
Authors: Christina Schilde, Anna Skiba and Pauline Schaap
Mammals exhibit a remarkable variety of phenotypes and comparative studies using novel model species are needed to uncover the evolutionary developmental mechanisms generating this diversity. Here, we undertak...
Authors: Sophie A Montandon, Athanasia C Tzika, António F Martins, Bastien Chopard and Michel C Milinkovitch
Annual killifishes inhabit temporary ponds and their embryos survive the dry season encased in the mud by entering diapause, a process that arrests embryonic development during hostile conditions. Annual killi...
Authors: Luca Dolfi, Roberto Ripa and Alessandro Cellerino
Cellular differentiation is a critical process during development of multicellular animals that must be tightly controlled in order to avoid precocious differentiation or failed generation of differentiated ce...
During development, juvenile nematodes undergo four molts. Although the number of molts appears to be constant within the Nematoda, the timing of the first molt can occur either before or after hatching. A pre...
The Hes superfamily or Hes/Hey-related genes encompass a variety of metazoan-specific bHLH genes, with somewhat fuzzy phylogenetic relationships. Hes superfamily members are involved in a variety of major develop...
Authors: Eve Gazave, Aurélien Guillou and Guillaume Balavoine
The teleost Astyanax mexicanus is a single species consisting of eyed surface-dwelling (surface fish) and blind cave-dwelling (cavefish) morphs. Cavefish eyes are lost through apoptosis of the lens, which in turn...
Authors: Li Ma, Amy Parkhurst and William R Jeffery
Disentangling evolutionary shifts in developmental timing (heterochony) is dependent upon accurate estimates of ancestral patterns. However, many classic assessments of heterochronic patterns predate robust ph...
Authors: Ronald M Bonett, Michael A Steffen and Grant A Robison
The primary hormone of the vertebrate pineal gland, melatonin, has been identified broadly throughout the eukaryotes. While the role for melatonin in cyclic behavior via interactions with the circadian clock h...
Authors: Rafael Peres, Adam M Reitzel, Yale Passamaneck, Solange Castro Afeche, José Cipolla-Neto, Antonio Carlos Marques and Mark Q Martindale
A particularly critical event in avian evolution was the transition from long- to short-tailed birds. Primitive bird tails underwent significant alteration, most notably reduction of the number of caudal verte...
Authors: Dana J Rashid, Susan C Chapman, Hans CE Larsson, Chris L Organ, Anne-Gaelle Bebin, Christa S Merzdorf, Roger Bradley and John R Horner
Segmentation is a feature of the body plans of a number of diverse animal groupings, including the annelids, arthropods and chordates. However, it has been unclear whether or not these different manifestations...
Authors: Anthony Graham, Thomas Butts, Andrew Lumsden and Clemens Kiecker
The Pax-Six-Eya-Dach network (PSEDN) is involved in a variety of developmental processes, including well documented roles in determination of sensory organs and morphogenesis in bilaterian animals. Expression of ...
Authors: Sofia AV Fortunato, Sven Leininger and Maja Adamska
The Hox gene cluster ranks among the greatest of biological discoveries of the past 30 years. Morphogenetic patterning genes are remarkable for the systems they regulate during major ontogenetic events, and fo...
The canals of the mechanosensory lateral line system are components of the dermatocranium, and demonstrate phenotypic variation in bony fishes. Widened lateral line canals evolved convergently in a limited num...
The bHLH-PAS transcription factors are found in both protostomes and deuterostomes. They are involved in many developmental and physiological processes, including regional differentiation of the central nervou...
Convergent evolution, the repeated evolution of similar phenotypes in independent lineages, provides natural replicates to study mechanisms of evolution. Cases of convergent evolution might have the same under...
Authors: Andrew M Glazer, Phillip A Cleves, Priscilla A Erickson, Angela Y Lam and Craig T Miller
Germline specification in some animals is driven by the maternally inherited germ plasm during early embryogenesis (inheritance mode), whereas in others it is induced by signals from neighboring cells in mid o...
Authors: Gee-way Lin, Charles E Cook, Toru Miura and Chun-che Chang
The Fox gene family is a large family of transcription factors that arose early in organismal evolution dating back to at least the common ancestor of metazoans and fungi. They are key components of many gene ...
Authors: Jens H Fritzenwanker, John Gerhart, Robert M Freeman Jr and Christopher J Lowe
Diapause is a developmental arrest present in annual killifish, whose eggs are able to survive long periods of desiccation when the temporary ponds they inhabit dry up. Diapause can occur in three different de...
Authors: Irma Varela-Lasheras and Tom JM Van Dooren
The Sox genes, a family of transcription factors characterized by the presence of a high mobility group (HMG) box domain, are among the central groups of developmental regulators in the animal kingdom. They are i...
Authors: Christine E Schnitzler, David K Simmons, Kevin Pang, Mark Q Martindale and Andreas D Baxevanis
