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Ciliary photoreceptors in the cerebral eyes of a protostome larva
(BioMed Central, 2011-03-01)
Background: Eyes in bilaterian metazoans have been described as being composed of either ciliary or
rhabdomeric photoreceptors. Phylogenetic distribution, as well as distinct morphologies and characteristic
deployment ...
Development of the larval anterior neurogenic domains of Terebratalia transversa (Brachiopoda) provides insights into the diversification of larval apical organs and the spiralian nervous system
(BioMed Central, 2012-01-24)
Background: 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 ...
Coordinated spatial and temporal expression of Hox genes during embryogenesis in the acoel Convolutriloba longifissura
(BioMed Central, 2009-10-01)
Background: Hox genes are critical for patterning the bilaterian anterior-posterior axis. The evolution of their clustered genomic arrangement and ancestral function has been debated since their discovery. As acoels appear ...
Gene expression in bryozoan larvae suggest a fundamental importance of pre-patterned blastemic cells in the bryozoan life-cycle
(BioMed Central, 2011-06-06)
Background: Bryozoa is a clade of aquatic protostomes. The bryozoan life cycle typically comprises a larval stage,
which metamorphoses into a sessile adult that proliferates by asexual budding to form colonies. The homology ...
Detailed reconstruction of the musculature in Limnognathia maerski (Micrognathozoa) and comparison with other Gnathifera
(BioMed Central, 2014-10-01)
Introduction: Limnognathia maerski is the single species of the recently described taxon, Micrognathozoa. The most conspicuous character of this animal is the complex set of jaws, which resembles an even more intricate ...
Development and juvenile anatomy of the nemertodermatid Meara stichopi (Bock) Westblad 1949 (Acoelomorpha)
(BioMed Central, 2014-07-07)
Introduction: Nemertodermatida is the sister group of the Acoela, which together form the Acoelomorpha, a taxon that comprises bilaterally symmetric, small aquatic worms. While there are several descriptions of the embryology ...
Xenacoelomorpha's significance for understanding bilaterian evolution
(Elsevier, 2016-08)
The Xenacoelomorpha, with its phylogenetic position as sister group of the Nephrozoa (Protostomia + Deuterostomia), plays a key-role in understanding the evolution of bilaterian cell types and organ systems. Current studies ...
Embracing the comparative approach: How robust phylogenies and broader developmental sampling impacts the understanding of nervous system evolution
(The Royal Society Publishing, 2015-11-09)
Molecular biology has provided a rich dataset to develop hypotheses of nervous system evolution. The startling patterning similarities between distantly related animals during the development of their central nervous system ...
Expression of segment polarity genes in brachiopods supports a non-segmental ancestral role of engrailed for bilaterians
(Nature Publishing Group, 2016-08-26)
The diverse and complex developmental mechanisms of segmentation have been more thoroughly studied in arthropods, vertebrates and annelids—distantly related animals considered to be segmented. Far less is known about the ...
Embryonic chirality and the evolution of spiralian left - right asymmetries
(The Royal Society Publishing, 2016-12)
The group Spiralia includes species with one of the most significant cases of left–right asymmetries in animals: the coiling of the shell of gastropod molluscs (snails). In this animal group, an early event of embryonic ...