Limits...
Genomic view of the evolution of the complement system.

Nonaka M, Kimura A - Immunogenetics (2006)

Bottom Line: Genome information from a few mammals, chicken, clawed frog, a few bony fish, sea squirt, fruit fly, nematoda and sea anemone indicate that bony fish and higher vertebrates share practically the same set of complement genes.Members of most complement gene families are also present in ascidians, although they do not show a one-to-one correspondence to their counterparts in higher vertebrates, indicating that the gene duplications of each gene family occurred independently in vertebrates and ascidians.The C3 and factor B genes, but probably not the other complement genes, are present in the genome of the cnidaria and some protostomes, indicating that the origin of the central part of the complement system was established more than 1,000 MYA.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Tokyo, Japan. mnonaka@biol.s.u-tokyo.ac.jp

ABSTRACT
The recent accumulation of genomic information of many representative animals has made it possible to trace the evolution of the complement system based on the presence or absence of each complement gene in the analyzed genomes. Genome information from a few mammals, chicken, clawed frog, a few bony fish, sea squirt, fruit fly, nematoda and sea anemone indicate that bony fish and higher vertebrates share practically the same set of complement genes. This suggests that most of the gene duplications that played an essential role in establishing the mammalian complement system had occurred by the time of the teleost/mammalian divergence around 500 million years ago (MYA). Members of most complement gene families are also present in ascidians, although they do not show a one-to-one correspondence to their counterparts in higher vertebrates, indicating that the gene duplications of each gene family occurred independently in vertebrates and ascidians. The C3 and factor B genes, but probably not the other complement genes, are present in the genome of the cnidaria and some protostomes, indicating that the origin of the central part of the complement system was established more than 1,000 MYA.

Show MeSH

Related in: MedlinePlus

Phylogenetic relationship among animals. Phylogenetic relationship among multicellular animals elucidated by molecular clock methods based on protein sequence data is shown. Only animal groups relevant to this review are included. The divergence times for the Arthropod/Nematoda or Mollusca/Annelida were not analyzed by this method and are arbitrarily shown in this figure
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2480602&req=5

Fig1: Phylogenetic relationship among animals. Phylogenetic relationship among multicellular animals elucidated by molecular clock methods based on protein sequence data is shown. Only animal groups relevant to this review are included. The divergence times for the Arthropod/Nematoda or Mollusca/Annelida were not analyzed by this method and are arbitrarily shown in this figure

Mentions: As molecular research proceeds, the evolutionary origin of the complement system was revealed to be increasingly ancient. Hence, it is necessary to understand a wider range of animal phylogeny to follow the evolutionary process of the complement system. The current view of animal phylogeny and estimated divergence times among major animal groups based on the recent molecular clock analyses (Blair and Hedges 2005a,b; Hedges et al. 2004) is summarized in Fig. 1. As shown in this figure, molecular data suggest that eumetazoa diverged into Cnidaria and Bilateralia about 1,300 MYA. At approximately 1,000 MYA, Bilateralia then diverged into Deuterostomia and Protostomia, and the latter diverged further into Ecdysozoa and Lophotrochozoa. In the Deuterostomia lineage, Chordata diverged from Echinodermata/Hemichordata around 900 MYA. Among three Chordata subphyla, Cephalochordata first diverged 890 MYA, and Urochordata and Vertebrata diverged 790 MYA. From the main Vertebrata lineage, Cyclostomata diverged 650 MYA and Chondrichthyes diverged 530 MYA. This phylogenetic tree, however, is still not conclusive; a recent report has suggested a close relationship between Cephalochordata and Echinodermata (Delsuc et al. 2006). The adaptive immunity based on lymphocytes and MHC is present in Chondrichthyes and other jawed vertebrates, but not in Cyclostomata. Thus, adaptive immunity most probably appeared between 530 and 650 MYA.Fig. 1


Genomic view of the evolution of the complement system.

Nonaka M, Kimura A - Immunogenetics (2006)

Phylogenetic relationship among animals. Phylogenetic relationship among multicellular animals elucidated by molecular clock methods based on protein sequence data is shown. Only animal groups relevant to this review are included. The divergence times for the Arthropod/Nematoda or Mollusca/Annelida were not analyzed by this method and are arbitrarily shown in this figure
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2480602&req=5

Fig1: Phylogenetic relationship among animals. Phylogenetic relationship among multicellular animals elucidated by molecular clock methods based on protein sequence data is shown. Only animal groups relevant to this review are included. The divergence times for the Arthropod/Nematoda or Mollusca/Annelida were not analyzed by this method and are arbitrarily shown in this figure
Mentions: As molecular research proceeds, the evolutionary origin of the complement system was revealed to be increasingly ancient. Hence, it is necessary to understand a wider range of animal phylogeny to follow the evolutionary process of the complement system. The current view of animal phylogeny and estimated divergence times among major animal groups based on the recent molecular clock analyses (Blair and Hedges 2005a,b; Hedges et al. 2004) is summarized in Fig. 1. As shown in this figure, molecular data suggest that eumetazoa diverged into Cnidaria and Bilateralia about 1,300 MYA. At approximately 1,000 MYA, Bilateralia then diverged into Deuterostomia and Protostomia, and the latter diverged further into Ecdysozoa and Lophotrochozoa. In the Deuterostomia lineage, Chordata diverged from Echinodermata/Hemichordata around 900 MYA. Among three Chordata subphyla, Cephalochordata first diverged 890 MYA, and Urochordata and Vertebrata diverged 790 MYA. From the main Vertebrata lineage, Cyclostomata diverged 650 MYA and Chondrichthyes diverged 530 MYA. This phylogenetic tree, however, is still not conclusive; a recent report has suggested a close relationship between Cephalochordata and Echinodermata (Delsuc et al. 2006). The adaptive immunity based on lymphocytes and MHC is present in Chondrichthyes and other jawed vertebrates, but not in Cyclostomata. Thus, adaptive immunity most probably appeared between 530 and 650 MYA.Fig. 1

Bottom Line: Genome information from a few mammals, chicken, clawed frog, a few bony fish, sea squirt, fruit fly, nematoda and sea anemone indicate that bony fish and higher vertebrates share practically the same set of complement genes.Members of most complement gene families are also present in ascidians, although they do not show a one-to-one correspondence to their counterparts in higher vertebrates, indicating that the gene duplications of each gene family occurred independently in vertebrates and ascidians.The C3 and factor B genes, but probably not the other complement genes, are present in the genome of the cnidaria and some protostomes, indicating that the origin of the central part of the complement system was established more than 1,000 MYA.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Tokyo, Japan. mnonaka@biol.s.u-tokyo.ac.jp

ABSTRACT
The recent accumulation of genomic information of many representative animals has made it possible to trace the evolution of the complement system based on the presence or absence of each complement gene in the analyzed genomes. Genome information from a few mammals, chicken, clawed frog, a few bony fish, sea squirt, fruit fly, nematoda and sea anemone indicate that bony fish and higher vertebrates share practically the same set of complement genes. This suggests that most of the gene duplications that played an essential role in establishing the mammalian complement system had occurred by the time of the teleost/mammalian divergence around 500 million years ago (MYA). Members of most complement gene families are also present in ascidians, although they do not show a one-to-one correspondence to their counterparts in higher vertebrates, indicating that the gene duplications of each gene family occurred independently in vertebrates and ascidians. The C3 and factor B genes, but probably not the other complement genes, are present in the genome of the cnidaria and some protostomes, indicating that the origin of the central part of the complement system was established more than 1,000 MYA.

Show MeSH
Related in: MedlinePlus