Hox genes in brachiopods and priapulids and protostome evolution

@article{Rosa1999HoxGI,
  title={Hox genes in brachiopods and priapulids and protostome evolution},
  author={Renaud de Rosa and Jennifer K. Grenier and Tatiana Andreeva and Charles E. Cook and Andr{\'e} Adoutte and Michael E Akam and Sean B. Carroll and Guillaume Balavoine},
  journal={Nature},
  year={1999},
  volume={399},
  pages={772-776}
}
Understanding the early evolution of animal body plans requires knowledge both of metazoan phylogeny and of the genetic and developmental changes involved in the emergence of particular forms. Recent 18S ribosomal RNA phylogenies suggest a three-branched tree for the Bilateria comprising the deuterostomes and two great protostome clades, the lophotrochozoans and ecdysozoans. Here, we show that the complement of Hox genes in critical protostome phyla reflects these phylogenetic relationships and… 

Hox genes from the Polystomatidae (Platyhelminthes, Monogenea).

Rotiferan Hox genes give new insights into the evolution of metazoan bodyplans

The expression of five Hox genes are reported during embryogenesis of the rotifer Brachionus manjavacas and it is shown how these genes define different functional components of the nervous system and not the usual bilaterian staggered expression along the anteroposterior axis.

Hox genes in the antarctic polyplacophoran Nuttallochiton mirandus.

Comparison with the results obtained in other molluscs seems to confirm the conservation of Hox genes in this phylum in terms of both presence and characteristics.

EVOLUTION OF HOX GENES IN MOLLUSCS: A COMPARISON AMONG SEVEN MORPHOLOGICALLY DIVERSE CLASSES

It is suggested that some of the anterior or posterior cognates have been lost in some lineages, most notably in Caudofoveata, while the medial cognates showed both losses and duplications.

Hox and ParaHox Genes in Flatworms: Characterization and Expression1

Flatworm Hox sequences and 18S rDNA sequence data support clear affinities of Platyhelminthes to spiralian lophotrochozoans, and Expression of Hox genes in intact and regenerating adult organisms show nested patterns with graded anterior expression boundaries, or ubiquitous expression.

Hox, ParaHox, ProtoHox: facts and guesses

Opposition views are discussed and it is proposed that the ProtoHox cluster had only two genes, and not four as commonly believed, which may help critical discussion of the evolution of the Hox/ParaHox family in the metazoan kingdom.

An Overview of Hox Genes in Lophotrochozoa: Evolution and Functionality

The data presented here suggest that at least nine genes were present while two other genes, Lox4 and Post-2, may either have been present in the ancestor or may have arisen as a result of duplication in the Brachiopoda-Mollusca-Annelida lineage.

Combined-method phylogenetic analysis of Hox and ParaHox genes of the metazoa.

ParaHox hypothesis is supported and first confirmation that ind (intermediate neuroblasts defective) is an anterior ParaHox ortholog from protostomes is given, as phylogenetic methods are used to determine Hox-gene orthologies and to infer probable clustering events leading to the current bilaterian Hox complement.
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