Hox genes encode transcription factors that have an ancestral role in all bilaterian animals in specifying regions along the antero-posterior axis. In arthropods (insects, crustaceans, myriapods and chelicerat...
Most geophilomorph centipedes show intraspecific variability in the number of leg-bearing segments. This intraspecific variability generally has a component that is related to sex, with females having on avera...
A complex life cycle, such as complete metamorphosis, is a key innovation that can promote diversification of species. The evolution of a morphologically distinct larval stage is thought to have enabled insect...
Authors: Alison K Lee, Christie C Sze, Elaine R Kim and Yuichiro Suzuki
During their evolution towards a complete life cycle on land, stem reptiles developed both an impermeable multi-layered keratinized epidermis and skin appendages (scales) providing mechanical, thermal, and che...
The “9th Okazaki Biology Conference: Marine Biology II” held at the National Institute for Basic Biology (NIBB) in Okazaki, Japan and at the Okinawa Institute of Science and Technology (OIST) in Okinawa, Japan...
In a previous study, we showed that the cephalochordate amphioxus Branchiostoma floridae has localized maternal transcripts of conserved germ cell markers Vasa and Nanos in its early embryos. These results provid...
The de novo assembly of transcriptomes from short shotgun sequencesraises challenges due to random and non-random sequencing biases andinherent transcript complexity. We sought to define a pipeline for denovo tra...
Authors: Sarah Tulin, Derek Aguiar, Sorin Istrail and Joel Smith
Various shapes of gastropod shells have evolved ever since the Cambrian. Although theoretical analyses of morphogenesis exist, the molecular basis of shell development remains unclear. We compared expression p...
Authors: Keisuke Shimizu, Minoru Iijima, Davin HE Setiamarga, Isao Sarashina, Tetsuhiro Kudoh, Takahiro Asami, Edi Gittenberger and Kazuyoshi Endo
Hox genes are the key determinants of different morphogenetic events in all bilaterian animals. These genes are probably responsible for the maintenance of regenerative capacities by providing positional infor...
Authors: Elena L Novikova, Nadezhda I Bakalenko, Alexander Y Nesterenko and Milana A Kulakova
Hox genes are the family of transcription factors that play a key role in the patterning of the anterior-posterior axis of all bilaterian animals. These genes display clustered organization and colinear expressio...
Authors: Nadezhda I Bakalenko, Elena L Novikova, Alexander Y Nesterenko and Milana A Kulakova
The neural crest represents a highly multipotent population of embryonic stem cells found only in vertebrate embryos. Acquisition of the neural crest during the evolution of vertebrates was a great advantage, ...
In most species of aphid, female nymphs develop into either sexual or asexual adults depending on the length of the photoperiod to which their mothers were exposed. The progeny of these sexual and asexual fema...
Authors: Ryan D Bickel, Hillary C Cleveland, Joanna Barkas, Caitlin C Jeschke, Amelie A Raz, David L Stern and Gregory K Davis
Despite the devastating global impact of mosquito-borne illnesses on human health, very little is known about mosquito developmental biology. In this investigation, functional genetic analysis of embryonic sal...
Authors: Chilinh Nguyen, Emily Andrews, Christy Le, Longhua Sun, Zeinab Annan, Anthony Clemons, David W Severson and Molly Duman-Scheel
Genes encoding TCP transcription factors, such as CYCLOIDEA-like (CYC-like) genes, are well known actors in the control of plant morphological development, particularly regarding the control of floral symmetry. D...
Authors: Regine Claßen-Bockhoff, Raili Ruonala, Kester Bull-Hereñu, Neville Marchant and Victor A Albert
Morphological innovation is an elusive and fascinating concept in evolutionary biology. A novel structure may open up an array of possibilities for adaptation, and thus is fundamental to the evolution of compl...
Authors: Barbara MI Vreede, Jeremy A Lynch, Siegfried Roth and Élio Sucena
Little is currently known about wing pattern development in the butterfly family Pieridae, which consists mostly of black melanized elements on white or yellow/orange backgrounds. A single transcription factor...
Authors: Andrew M Stoehr, Joseph F Walker and Antónia Monteiro
On 12 February 1988 (by coincidence Charles Darwin’s birthday), a paper published in Science by Katherine Field, Rudy Raff, and colleagues presented the first credible molecular analysis of metazoan phylogeny bas...
Arthropod and vertebrate appendages appear to have evolved via parallel co-option of a plesiomorphic gene regulatory network. Our previous work implies that annelids evolved unrelated appendage-forming mechani...
Authors: Christopher J Winchell and David K Jacobs
The fish-tetrapod transition was one of the major events in vertebrate evolution and was enabled by many morphological changes. Although the transformation of paired fish fins into tetrapod limbs has been a ma...
Authors: Catherine Anne Boisvert, Jean MP Joss and Per E Ahlberg
Germline determination is believed to occur by either preformation or epigenesis. Animals that undergo germ cell specification by preformation have a continuous germline. However, animals with germline determi...
The biting edge of the primitive arthropod mandible consists of a biting incisor process and a crushing molar process. These structures are thought to be derived from a structure known as an endite but the pre...
Authors: Joshua F Coulcher and Maximilian J Telford
In most eumetazoans studied so far, Hox genes determine the identity of structures along the main body axis. They are usually linked in genomic clusters and, in the case of the vertebrate embryo, are expressed wi...
Authors: Juan Pascual-Anaya, Noritaka Adachi, Susana Álvarez, Shigeru Kuratani, Salvatore D’Aniello and Jordi Garcia-Fernàndez
Digital anatomical atlases are increasingly used in order to depict different gene expression patterns and neuronal morphologies within a standardized reference template. In evo-devo, a discipline in which the...
Authors: Albina Asadulina, Aurora Panzera, Csaba Verasztó, Christian Liebig and Gáspár Jékely
The Hawaiian endemic genus Clermonti a (Campanulaceae) includes 22 species, 15 of which, the double-corolla species, are characterized by an extra whorl of organs that appear to be true petals occupying what is n...
Authors: Katherine A Hofer, Raili Ruonala and Victor A Albert
The biting mandible of the arthropods is thought to have evolved in the ancestor of the insects, crustaceans and myriapods: the Mandibulata. A unique origin suggests a common set of developmental genes will be...
Authors: Joshua F Coulcher and Maximilian J Telford
The vertebrate pharyngeal apparatus, serving the dual functions of feeding and respiration, has its embryonic origin in a series of bulges found on the lateral surface of the head, the pharyngeal arches. Devel...
Neuronal antibodies that show immunoreactivity across a broad range of species are important tools for comparative neuroanatomy. Nonetheless, the current antibody repertoire for non-model invertebrates is limi...
Activity of the Transforming growth factor-β (TGFβ) pathway is essential to the establishment of body axes and tissue differentiation in bilaterians. Orthologs for core pathway members have been found in all m...
Authors: Gina M Sorrentino, William Q Gillis, Jamina Oomen-Hajagos and Gerald H Thomsen
Animals with a spiral cleavage program, such as mollusks and annelids, make up the majority of the superphylum Lophotrochozoa. The great diversity of larval and adult body plans in this group emerges from this...
Authors: Deirdre C Lyons, Kimberly J Perry, Maryna P Lesoway and Jonathan Q Henry
Variation in fruit morphology is important for plant fitness because it influences dispersal capabilities. Approximately half the members of tribe Brassiceae (Brassicaceae) exhibit fruits with segmentation and...
Authors: Mariano Avino, Elena M Kramer, Kathleen Donohue, Alexander J Hammel and Jocelyn C Hall
The gastrula stage represents the point in development at which the three primary germ layers diverge. At this point the gene regulatory networks that specify the germ layers are established and the genes that...
Authors: Roy Vaughn, Nancy Garnhart, James R Garey, W Kelley Thomas and Brian T Livingston
The timing of the placental mammal radiation has been a source of contention for decades. The fossil record of mammals extends over 200 million years, but no confirmed placental mammal fossils are known prior ...
The mechanisms by which the conserved genetic “toolkit” for development generates phenotypic disparity across metazoans is poorly understood. Echinoderm larvae provide a great resource for understanding how de...
Authors: Brenna S McCauley, Erin P Wright, Cameron Exner, Chisato Kitazawa and Veronica F Hinman
Talpid moles show many specializations in their adult skeleton linked to fossoriality, including enlarged hands when compared to the feet. Heterochrony in developmental mechanisms is hypothesized to account fo...
Authors: Constanze Bickelmann, Christian Mitgutsch, Michael K Richardson, Rafael Jiménez, Merijn AG de Bakker and Marcelo R Sánchez-Villagra
Intercellular signaling via the Notch pathway regulates cell fate, patterning, differentiation and proliferation, and is essential for the proper development of bilaterians and cnidarians. To investigate the o...
Sox genes are HMG-domain containing transcription factors with important roles in developmental processes in animals; many of them appear to have conserved functions among eumetazoans. Demosponges have fewer S...
Authors: Sofia Fortunato, Marcin Adamski, Brith Bergum, Corina Guder, Signe Jordal, Sven Leininger, Christin Zwafink, Hans Tore Rapp and Maja Adamska
Conway Morris and Caron (2012) have recently published an account of virtually all the available information on Pikaia gracilens, a well-known Cambrian fossil and supposed basal chordate, and propose on this basi...
Plant development has a significant postembryonic phase that is guided heavily by interactions between the plant and the outside environment. This interplay is particularly evident in the development, pattern ...
Recent studies have challenged the widespread view that the pattern of embryogenesis found in Caenorhabditis elegans (clade 9) is characteristic of nematodes in general. To understand this still largely unexplore...
Authors: Jens Schulze, Wouter Houthoofd, Jana Uenk, Sandra Vangestel and Einhard Schierenberg
The enigmatic wormlike parasite Buddenbrockia plumatellae has recently been shown to belong to the Myxozoa, which are now supported as a clade within Cnidaria. Most myxozoans are morphologically extremely simplif...
In the polychaete Platynereis, the primordial germ cells (PGCs) emerge from the vasa, piwi, and PL10 expressing mesodermal posterior growth zone (MPGZ) at the end of larval development, suggesting a post-embryoni...
Authors: Nicole Rebscher, Anika Kristin Lidke and Christian Friedrich Ackermann
Annelids and arthropods each possess a segmented body. Whether this similarity represents an evolutionary convergence or inheritance from a common segmented ancestor is the subject of ongoing investigation.
Authors: Elaine C Seaver, Emi Yamaguchi, Gemma S Richards and Néva P Meyer
Flatworm embryology has attracted attention since the early beginnings of comparative evolutionary biology. Considered for a long time the most basal bilaterians, the Platyhelminthes (excluding Acoelomorpha) a...
Authors: José María Martín-Durán and Bernhard Egger
Flower bilateral symmetry (zygomorphy) has evolved multiple times independently across angiosperms and is correlated with increased pollinator specialization and speciation rates. Functional and expression ana...
This paper is a short report on the 2012 Society of Integrative and Comparative Biology Annual Meeting. Charleston, South Carolina, USA. 3-7 January 2012 (abstracts freely available at
Gene duplication and the subsequent divergence in function of the resulting paralogs via subfunctionalization and/or neofunctionalization is hypothesized to have played a major role in the evolution of plant f...
Authors: Ashley R Christensen and Simon T Malcomber
Larval features such as the apical organ, apical ciliary tuft, and ciliated bands often complicate the evaluation of hypotheses regarding the origin of the adult bilaterian nervous system. Understanding how ne...
Authors: Scott Santagata, Carlee Resh, Andreas Hejnol, Mark Q Martindale and Yale J Passamaneck
Nervous systems are thought to be important to the evolutionary success and diversification of metazoans, yet little is known about the origin of simple nervous systems at the base of the animal tree. Recent d...
Authors: David K Simmons, Kevin Pang and Mark Q Martindale
