The evolution of vertebrate blood coagulation as viewed from a comparison of puffer fish and sea squirt genomes

Abstract

The blood coagulation scheme for the puffer fish, Fugu rubripes, has been reconstructed on the basis of orthologs of genes for mammalian blood clotting factors being present in its genome. As expected, clotting follows the same fundamental pattern as has been observed in other vertebrates, even though genes for some clotting factors found in mammals are absent and some others are present in more than one gene copy. All told, 26 different proteins involved in clotting or fibrinolysis were searched against the puffer fish genome. Of these, orthologs were found for 21. Genes for the ''contact system'' factors (factor XI, factor XII, and prekallikrein) could not be identified. On the other hand, two genes were found for factor IX and four for factor VII. It was evident that not all four factor VII genes are functional, essential active-site residues having been replaced in two of them. A search of the genome of a urochordate, the sea squirt, Ciona intestinalis, did not turn up any genuine orthologs for these 26 factors, although paralogs and͞or constituent domains were evident for virtually all of them.blood clotting ͉ domain shuffling

Stepwise formation of the bacterial flagellar system

“…However, the analysis of biological complexity has changed with the application both of genetic procedures that serve to identify the contribution of individual genes to a phenotype and of comparative sequence analyses that can elucidate the evolutionary and functional relationships among genes that occur in all life-forms. As with the evolution of other complex structures and processes (29)(30)(31)(32), we have shown the bacterial flagellum too originated from ''so simple a beginning,'' in this case, a single gene that underwent successive duplications and subsequent diversification during the early evolution of Bacteria.…”

Vitamin K-dependent proteins in Ciona intestinalis , a basal chordate lacking a blood coagulation cascade

“…Both Ci-Gla1 and Cs-Gla1 lacked a discernible signal peptide and aligned most closely with Gla-RTK, a receptor tyrosine kinase from the ascidian Halocynthia roretzi (23). The presence of four potential Gla domainencoding sequences within the C. intestinalis genome has also been reported as part of an in silico analysis of the protein domains involved in vertebrate blood coagulation and fibrinolysis (22).…”

“…In a recent report comparing the puffer fish and ascidian genomes, Jiang and Doolittle (22) have proposed that the Gla-EGF 2 -serine protease prototype evolved directly from prothrombin by the exchange of the two prothrombin kringle domains with two EGF domains. Our findings, however, suggest an alternative model in which the Gla-EGF 2 -serine protease prototype arose independently of prothrombin.…”

“…The vertebrate origin of the Gla domain, however, has been challenged by recent reports indicating the presence of Gla domain proteins in ascidians, marine invertebrates of the chor- date subphylum Urochordata (22,23). The identification of ascidian Gla domain proteins is significant for several reasons.…”

ATP-binding Cassette Transporter A1 Contains a Novel C-terminal VFVNFA Motif That Is Required for Its Cholesterol Efflux and ApoA-I Binding Activities

“…Thus, the lack of the motif in transporters from the urochordate C. intestinalis and lower invertebrate organisms and its presence in transporters of fish, birds, and mammals indicate that the motif likely arose early in the divergence of the vertebrate lineage. This occurred ϳ450 million years ago, at a time when complex closed circulatory systems first evolved (37)(38)(39). Unlike the PDZ binding motif, the VFVNFA sequence is required for ABCA1 to form a complex with apoA-I and to transfer cholesterol to the apolipoprotein.…”