PUBLICATION
Conservation of a vitellogenin gene cluster in oviparous vertebrates and identification of its traces in the platypus genome
- Authors
- Babin, P.J.
- ID
- ZDB-PUB-080326-22
- Date
- 2008
- Source
- Gene 413(1-2): 76-82 (Journal)
- Registered Authors
- Babin, Patrick J.
- Keywords
- Comparative genomics, Gene duplication, Large lipid transfer protein superfamily, Reproduction, Vertebrate, Yolk
- MeSH Terms
-
- Animals
- Bayes Theorem
- Conserved Sequence
- Evolution, Molecular
- Female
- Fishes/classification
- Fishes/genetics
- Mammals/classification
- Mammals/genetics
- Models, Genetic
- Multigene Family*
- Oviparity/genetics*
- Phylogeny
- Platypus/classification
- Platypus/genetics*
- Vertebrates/classification
- Vertebrates/genetics*
- Vitellogenins/genetics*
- PubMed
- 18343608 Full text @ Gene
Citation
Babin, P.J. (2008) Conservation of a vitellogenin gene cluster in oviparous vertebrates and identification of its traces in the platypus genome. Gene. 413(1-2):76-82.
Abstract
Vitellogenin (Vtg) derivatives are the main egg-yolk proteins in most oviparous animal species, and are, therefore, key players in reproduction and embryo development. Conserved synteny and phylogeny were used to identify a Vtg gene cluster (VGC) that had been evolutionarily conserved in most oviparous vertebrates, encompassing the three linked Vtgs on chicken (Gallus gallus) chromosome 8. Tandem arranged homologs to chicken VtgII and VtgIII were retrieved in similar locations in Xenopus (Xenopus tropicalis) and homologous transcribed inverted genes were found in medaka (Oryzias latipes), stickleback (Gasterosteus aculeatus), pufferfish (Takifugu rubripes), and Tetrahodon (Tetraodon nigroviridis), while zebrafish (Danio rerio) Vtg3 may represent a residual trace of VGC in this genome. Vtgs were not conservetipes), stickleback (Gasterosteus aculeatus), pufferfish (Takifugu rubripes), and Tetrahodon (Tetraodon nigroviridis), while zed in the paralogous chromosomal segment attributed to a whole-genome duplication event in the ancestor of teleosts, while tandem duplicated forms have survived the recent African clawed frog (Xenopus laevis) tetraploidization. Orthologs to chicken VtgI were found in similar locations in teleost fish, as well as in the platypus (Ornithorhynchus anatinus). Additional Vtg fragments found suggested that VGC had been conserved in this egg-laying mammal. A low ratio of nonsynonymous-to-synonymous substitution values and the paucity of pseudogene features suggest functional platypus Vtg products. Genomic identification of Vtgs, Apob, and Mtp in this genome, together with maximum likelihood and Bayesian inference phylogenetic analyses, support the existence of these three large lipid transfer protein superfamily members at the base of the mammalian lineage. In conclusion, the establishment of a VGC in the vertebrate lineage predates the divergence of ray-finned fish and tetrapods and the shift in reproductive and developmental strategy observed between prototherians and therians may be associated with its loss, as shown by its absence from the genomic resources currently available from therians.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping