GEPHE SUMMARY
Gephebase Gene
Entry Status
Published
GepheID
GP00001946
Main curator
Courtier
PHENOTYPIC CHANGE
Trait Category
Trait State in Taxon A
-
Trait State in Taxon B
loss of segments
Ancestral State
Taxon A
Taxonomic Status
Taxon A
Common Name
fruit fly
Synonyms
Sophophora melanogaster; fruit fly; Drosophila melanogaster Meigen, 1830; Sophophora melanogaster (Meigen, 1830); Drosophila melangaster
Rank
species
Lineage
Show more ... Brachycera; Muscomorpha; Eremoneura; Cyclorrhapha; Schizophora; Acalyptratae; Ephydroidea; Drosophilidae; Drosophilinae; Drosophilini; Drosophila; Sophophora; melanogaster group; melanogaster subgroup
NCBI Taxonomy ID
is Taxon A an Infraspecies?
No
Taxon B #1
Common Name
-
Synonyms
Hypsibius dujardini (Doyere, 1840); Hypsibius dujardinii
Rank
species
Lineage
cellular organisms; Eukaryota; Opisthokonta; Metazoa; Eumetazoa; Bilateria; Protostomia; Ecdysozoa; Panarthropoda; Tardigrada; Eutardigrada; Parachela; Hypsibioidea; Hypsibiidae; Hypsibius
NCBI Taxonomy ID
is Taxon B an Infraspecies?
No
Taxon B #2
Common Name
-
Synonyms
Macrobiotus richtersi; Macrobiotus schultzei; Paramacrobiotus richtersi (Murray, 1911)
Rank
species
Lineage
Show more ... Opisthokonta; Metazoa; Eumetazoa; Bilateria; Protostomia; Ecdysozoa; Panarthropoda; Tardigrada; Eutardigrada; Parachela; Macrobiotoidea; Macrobiotidae; Paramacrobiotus; Paramacrobiotus richtersi group
NCBI Taxonomy ID
is Taxon B an Infraspecies?
No
Taxon B #3
Common Name
-
Synonyms
Milnesium tardigradum Doyere, 1840
Rank
species
Lineage
cellular organisms; Eukaryota; Opisthokonta; Metazoa; Eumetazoa; Bilateria; Protostomia; Ecdysozoa; Panarthropoda; Tardigrada; Eutardigrada; Apochela; Milnesiidae; Milnesium
NCBI Taxonomy ID
is Taxon B an Infraspecies?
No
GENOTYPIC CHANGE
Presumptive Null
Yes
Molecular Type
Aberration Type
Deletion Size
unknown
Molecular Details of the Mutation
The three genes Antp Ubx AbdA are missing in the genome sequences of the three tardigrades. This loss is ancient so difficult to evaluate whether the three genes were lost due to a single mutational event or due to successive mutations. The Hox cluster is disorganized in the H. dujardini genome.
Experimental Evidence
Authors
Smith FW; Boothby TC; Giovannini I; Rebecchi L; Jockusch EL; Goldstein B
Abstract
The superphylum Panarthropoda (Arthropoda, Onychophora, and Tardigrada) exhibits a remarkable diversity of segment morphologies, enabling these animals to occupy diverse ecological niches. The molecular identities of these segments are specified by Hox genes and other axis patterning genes during development [1, 2]. Comparisons of molecular segment identities between arthropod and onychophoran species have yielded important insights into the origins and diversification of their body plans [3-9]. However, the relationship of the segments of tardigrades to those of arthropods and onychophorans has remained enigmatic [10, 11], limiting our understanding of early panarthropod body plan diversification. Here, we reveal molecular identities for all of the segments of a tardigrade. Based on our analysis, we conclude that tardigrades have lost a large intermediate region of the body axis-a region corresponding to the entire thorax and most of the abdomen of insects-and that they have lost the Hox genes that originally specified this region. Our data suggest that nearly the entire tardigrade body axis is homologous to just the head region of arthropods. Based on our results, we reconstruct a last common ancestor of Panarthropoda that had a relatively elongate body plan like most arthropods and onychophorans, rather than a compact, tardigrade-like body plan. These results demonstrate that the body plan of an animal phylum can originate by the loss of a large part of the body.

Copyright © 2016 Elsevier Ltd. All rights reserved.
Additional References
RELATED GEPHE
Related Genes
No matches found.
Related Haplotypes
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