Monophyly of Lampreys and Hagfishes Supported by Nuclear DNA–Coded Genes

  title={Monophyly of Lampreys and Hagfishes Supported by Nuclear DNA–Coded Genes},
  author={Shigehiro Kuraku and Daisuke Hoshiyama and Kazutaka Katoh and Hiroshi Suga and Takashi Miyata},
  journal={Journal of Molecular Evolution},
Abstract. The phylogenetic position of hagfishes in vertebrate evolution is currently controversial. The 18S and 28S rRNA trees support the monophyly of hagfishes and lampreys. In contrast, the mitochondrial DNAs suggest the close association of lampreys and gnathostomes. To clarify this controversial issue, we have conducted cloning and sequencing of the four nuclear DNA–coded single-copy genes encoding the triose phosphate isomerase, calreticulin, and the largest subunit of RNA polymerase II… 
Complete mitochondrial DNA of the hagfish, Eptatretus burgeri: the comparative analysis of mitochondrial DNA sequences strongly supports the cyclostome monophyly.
Molecular data, i.e., results and those obtained using nuclear genes, conclude that hagfishes and lampreys form a clade, and unequivocally supported the monophyly of cyclostomes.
Time Scale for Cyclostome Evolution Inferred with a Phylogenetic Diagnosis of Hagfish and Lamprey cDNA Sequences
The evolutionary configuration indicates that Myxiniformes and Petromyzoniformes diverged shortly after the common ancestor of cyclostomes split from the future gnathostome lineage.
Molecular phylogeny and divergence times of deuterostome animals.
It is found that most major lineages of deuterostomes arose prior to the Cambrian Explosion of fossils and that several lineages had originated before periods of global glaciation in the Precambrian.
Analysis of lamprey and hagfish genes reveals a complex history of gene duplications during early vertebrate evolution.
The analysis suggests that numerous gene losses and other gene-genome duplications occurred during the evolution of the vertebrate genomes, which should be explained by the contribution of genome duplications (2R hypothesis), extra gene duplications, and gene losses.
Impact of asymmetric gene repertoire between cyclostomes and gnathostomes.
  • S. Kuraku
  • Biology
    Seminars in cell & developmental biology
  • 2013
Non-parsimonious evolution of hagfish Dlx genes
Independent duplication, pseudogenization, and loss of the Dlx genes probably occurred in the hagfish lineage after its split from the other vertebrate lineages, reminiscent of the non-parsimonious evolution of its morphological traits, including its inner ear and vertebrae.
Insights into Cyclostome Phylogenomics: Pre-2R or Post-2R
The hypothesis that two-round (2R) genome duplication events occurred before the divergence between cyclostomes and gnathostomes, and therefore that a post-2R state is a genomic synapomorphy for all extant vertebrates is focused on.
microRNAs reveal the interrelationships of hagfish, lampreys, and gnathostomes and the nature of the ancestral vertebrate
Fundamental conservation of microRNA expression patterns among lamprey, hagfish, and gnathostome organs, implying that the role of microRNAs within specific organs is coincident with their appearance within the genome and is conserved through time, support the monophyletic of cyclostomes and suggest that the last common ancestor of all living vertebrates was a more complex organism than conventionally accepted.
Molecular phylogeny of early vertebrates: monophyly of the agnathans as revealed by sequences of 35 genes.
This work uses the sequences of 35 nuclear protein-encoding genes to provide definitive evidence for the monophyly of the Agnatha (jawless vertebrates, a group encompassing the hagfishes and lampreys).


28S and 18S rDNA sequences support the monophyly of lampreys and hagfishes.
Moderate to very strong support is provided for the monophyly of the cyclostomes in lampreys plus hagfishes and the currently accepted hypothesis of a lamprey-gnathostome clade is moderately rejected by the Kishino-Hasegawa test and resoundingly rejected by parametric bootstrap tests.
Evidence from 18S ribosomal RNA sequences that lampreys and hagfishes form a natural group.
Phylogenetic comparisons of 18S ribosomal RNA sequences from two hagfishes, two lampreys, a tunicate, a lancelet, and a number of gnathostomes support the monophyly of the cyclostomes, forcing a reassessment of several features of early vertebrate evolution.
Sequence analysis of vasotocin cDNAs of the lamprey, Lampetra japonica, and the hagfish, Eptatretus burgeri: evolution of cyclostome vasotocin precursors.
The phylogenetic tree with the highest bootstrap probability showed that the lamprey VT precursor is more closely related to the gnathostome VT and VP precursors than to the hagfish VT precursor.
Protein Tyrosine Kinase cDNAs from Amphioxus, Hagfish, and Lamprey: Isoform Duplications Around the Divergence of Cyclostomes and Gnathostomes
It is shown that the isoform duplications frequently occurred in the early evolution of vertebrates around or just before the divergence of cyclostomes and gnathostomes by gene duplications and possibly chromosomal duplications.
Extensive Gene Duplication in the Early Evolution of Animals Before the Parazoan–Eumetazoan Split Demonstrated by G Proteins and Protein Tyrosine Kinases from Sponge and Hydra
The pattern of gene diversification during animal evolution might be characterized by bursts of gene duplication interrupted by considerably long periods of silence, instead of proceeding gradually, and there might be no direct link between the Cambrian explosion and the extensive gene duplication that generated diverse functions (subtypes) of these families.
Intermittent divergence of the protein tyrosine kinase family during animal evolution
Evolution of gene families and relationship with organismal evolution: rapid divergence of tissue-specific genes in the early evolution of chordates.
A phylogenetic analysis of tissue-specific isoforms from 26 different subfamilies revealed extensive gene duplications and rapid rates of amino acid substitutions in the early evolution of chordates before the separation of fishes and tetrapods.
Molecular clock for dating of divergence between animal phyla.
It was found that four proteins, particularly the aldolase C, involved in the glycolitic pathway, had evolved with rates that are approximately constant not only among different classes of vertebrates, but also between vertebrates and arthropods.
The phylogeny of the Craniata, with particular reference to the significance of fossil “agnathans”
It is concluded that the fossil jawless Craniata provide little information on the affinities of the CraniATA, but they do provide complementary data on distribution of characters.
Structures of cDNAs encoding the muscle-type and non-muscle-type isozymes of lamprey fructose bisphosphate aldolases and the evolution of aldolase genes.
Northern blot analyses using the 3'-noncoding sequences of cDNA-M8 and -L3 as hybridization probes indicated that the muscle-type mRNA is expressed mainly in the skeletal muscle, heart muscle, brain, and some other tissues, but probably not in liver, while the non-muscle-type RNA is expressed mostly in the liver and also in brain and other tissues; except for the heart muscle.