Evolution of Hox genes in molluscs: a comparison among seven morphologically diverse classes

Iijima, Mayumi; Akiba, Natsumi; Sarashina, Isao; Kuratani, Shigeru; Endo, Kazuhiko

doi:10.1093/mollus/eyl001

Cited by 24 publications

(27 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As regards the central class, the Nmi-Scr sequence reveals high similarity with the Scr of other molluscs, with conservation of the characteristic tyrosine and lysine amino acid residues in positions 20 and 22, respectively, and a serine in position 35, as was found in the Hox5a sequences of the chiton and the solenogast studied by Iijima et al (2006). At variance with Iijima et al (2006), we identified a single sequence attributable to the Scr gene in N. mirandus.…”

Section: Resultssupporting

confidence: 51%

“…The orthology of Nmi-lab to paralog group 1 is supported by diagnostic amino acid residues in positions 27, 39 and 41. The Nmi-lab sequence is identical to the amino acid sequence of the Hox1 of the chiton Acantopleura japonica (Iijima et al, 2006) and is highly similar to the sequences of pectinids P. maximus (Canapa et al, 2005) and Pecten yessoensis (Iijima et al, 2006) due to the serine in position 35. The Nmi-pb sequence is identical to that of the pb of other protostomes, with the amino acid aspartic acid in position 37, which is present in all the organisms analysed so far with the exception of the scaphopod Dentalium octangulatum (Iijima et al, 2006).…”

Section: Resultsmentioning

confidence: 60%

“…At variance with Iijima et al (2006), we identified a single sequence attributable to the Scr gene in N. mirandus. However, the data presented by these researchers do not support with certainty a duplication of this gene.…”

Section: Resultsmentioning

confidence: 93%

“…Total DNA was extracted using the QIAGEN (Hilden, Germany) DNeasy Tissue Kit and then PCR-amplified using degenerate primers designed by Murtha et al ('91) (Iijima et al, 2006) and the other classes of the phylum Mollusca: Bivalvia (Barucca et al, 2003;Canapa et al, 2005;Iijima et al, 2006), Cephalopoda (Callaerts et al, 2002;Iijima et al, 2006;Pernice et al, 2006), Gastropoda (Degnan and Morse, '93;de Rosa et al, '99;Hinman et al, 2003;Iijima et al, 2006), Solenogasters (Iijima et al, 2006), Caudofoveata (Iijima et al, 2006) and Scaphopoda (Iijima et al, 2006). The four classes of Hox genes are highlighted in different colours: anterior genes (black), group3 (dark grey), central genes (light grey), and posterior (white).…”

Section: Methodsmentioning

confidence: 99%

“…Hox genes have been studied in six species of bivalves (Barucca et al, 2003;Canapa et al, 2005;Iijima et al, 2006), with the complete 11-gene cluster being identified in Pecten maximus (Canapa et al, 2005). Analysis of four gastropod (Degnan and Morse, '93;de Rosa et al, '99;Giusti et al, 2000;Hinman et al, 2003;Iijima et al, 2006) and four cephalopod (Callaerts et al, 2002;Iijima et al, 2006;Pernice et al, 2006) species has identified all the genes of the Hox cluster in these two classes, even though the complete cluster has not yet been identified. Iijima et al (2006) have also isolated ten Hox genes in Scaphopoda, six in Polyplacophora, eight in Solenogastres and five in Caudofoveata by examining one species per class.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Hox genes in the antarctic polyplacophoran Nuttallochiton mirandus

et al. 2007

View full text Add to dashboard Cite

Hox genes are conserved across all bilaterians and encode transcription factors involved in the formation of the anteroposterior axis during embryo development. Differences in homeotic gene evolution have been observed not only between deuterostomes and protostomes, but also between the two large protostome clades, Ecdysozoa and Lophotrochozoa.Among lophotrochozoans, the phylum Mollusca displays high diversity of body plans, ranging from the wormlike appearance of aplacophorans to the complex body plan of cephalopods. Using a PCRbased method, we were able to identify eight Hox genes in the polyplacophoran Nuttallochiton mirandus, two orthologous to the anterior class (lab, pb), four to the central class (Scr, Lox5, Antp, Lox2) and two to the posterior class (Post-1, Post-2). 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.

show abstract

Section: Resultssupporting

confidence: 51%

Section: Resultsmentioning

confidence: 60%

Section: Resultsmentioning

confidence: 93%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Hox genes in the antarctic polyplacophoran Nuttallochiton mirandus

et al. 2007

View full text Add to dashboard Cite

show abstract

Evolutionary Developmental Biology:HoxGene Evolution

Manzanares¹,

Krumlauf²

2012

Encyclopedia of Life Sciences

View full text Add to dashboard Cite

Hox genes are the homologues of the homeobox‐containing genes in the homeotic complex (HOM‐C) of the fruit fly Drosophila and encode transcription factors that play crucial roles in determining positional identity along the anterior–posterior body axis during animal development. Their expansion and duplication during metazoan evolution suggests that they have played a major role in generating animal diversity. In the protostomes, Hox genes are organised into a single cluster of genes that in some phyla has undergone gene loss and in others has become dispersed. On the contrary, cluster integrity is generally maintained in the deuterostomes, and during chordate evolution the single deuterostome cluster has undergone internal expansion as well as whole cluster duplications, generating animals with four or more clusters. Whereas these expansions and duplications are correlated with an increase in animal diversity, the main mechanisms driving metazoan evolution from a Hox perspective probably involve alterations in cis ‐regulatory sequences of Hox genes and, to a lesser extent, changes in their coding sequences. Key Concepts: The prototype Hox gene potentially evolved from an ancestral NK homeobox gene very early in metazoan evolution. Tandem and genome‐wide duplications generated the prototypical vertebrate Hox clusters. Hox genes encode transcription factors that may have originally patterned bilaterian's evolving nervous system; however, as body organisation became more complicated and cells became more interdependent, Hox genes’ function may have co‐evolved with the function of other HB‐containing genes to jointly specify positional information in the derivatives of all three germ layers. The clustering of Hox genes appears to be necessary for animals that use signalling pathways during development. This supports the presence of global control mechanisms that regulate all or a subset of genes within the cluster. Organisms in which cells are primarily determined in early embryogenesis and develop autonomously begin to lose Hox cluster integrity. The major morphological diversity in vertebrate lineages does not appear to be causally related to changes in the number or complement of the Hox genes. Therefore, Hox input into morphological diversity is likely to occur through altered cis ‐regulation and/or downstream targets of Hox genes. As the genome sequence of more species becomes available, the molecular phylogenetics of Hox cluster evolution will become clearer with an emphasis in understanding the evolution of the regulatory modules that partition Hox expression domains.

show abstract

Hox and ParaHox genes: A review on molluscs

Biscotti

Canapa

Forconi

et al. 2014

Genesis

View full text Add to dashboard Cite

Summary: Hox and ParaHox genes are involved in patterning the anterior-posterior body axis in metazoans during embryo development. Body plan evolution and diversification are affected by variations in the number and sequence of Hox and ParaHox genes, as well as by their expression patterns. For this reason Hox and ParaHox gene investigation in the phylum Mollusca is of great interest, as this is one of the most important taxa of protostomes, characterized by a high morphological diversity. The comparison of the works reviewed here indicates that species of molluscs, belonging to different classes, share a similar composition of Hox and ParaHox genes. Therefore evidence suggests that the wide morphological diversity of this taxon could be ascribed to differences in Hox gene interactions and expressions and changes in the Hox downstream genes rather than to Hox cluster composition. Moreover the data available on Hox and ParaHox genes in molluscs compared with those of other Lophotrochozoa shed light on the complex and controversial evolutionary histories that these genes have undergone within protostomes. genesis 52:935-945, 2014. V C 2014Wiley Periodicals, Inc.Key words: Hox genes; ParaHox genes; molluscs; ProtoHox cluster HOX AND PARAHOX GENES: EVOLUTIONARY HYPOTHESESBoth Hox and ParaHox genes belong to the ANTP homeobox gene class, which also includes the NK genes, the NK-related genes, the Dlx genes, and many more (Holland, 2013). It has been hypothesized that the ancestor genes of the current ANTP class were originally arranged in a single cluster called "Megacluster" (Garcıa-Fernandez, 2005a;Holland, 2013).The comparison of Hox and ParaHox gene number is interesting in order to reconstruct the evolutionary history of these gene families. In this regard the increase in sequenced genomes is providing significant data concerning the Hox and ParaHox gene complement in several organisms.Considering the early appearance of NK genes during evolution and their genomic proximity to the Hox genes in some species (Larroux et al., 2007), Holland (2013 proposed the ProtoHox cluster as originating from a ProtoNK cluster. Given the lack of Hox and ParaHox genes in basal metazoans, such as the demosponge Amphimedon queenslandica (Larroux et al., 2007) and the lobate ctenophore Mnemiopsis leidyi, it has been hypothesized (Ryan et al., 2010) that the ProtoHox gene/cluster could have arisen after the divergence of Porifera and Ctenophora from ParaHoxozoa (Placozoa, Cnidaria, and Bilateria). However, the phylogenetic relationships among basal metazoans are still

show abstract

Evolution of Hox genes in molluscs: a comparison among seven morphologically diverse classes

Cited by 24 publications

References 27 publications

Hox genes in the antarctic polyplacophoran Nuttallochiton mirandus

Hox genes in the antarctic polyplacophoran Nuttallochiton mirandus

Evolutionary Developmental Biology:HoxGene Evolution

Hox and ParaHox genes: A review on molluscs

Contact Info

Product

Resources

About