| Popis: |
Lampreys and hagfish are the only extant lineages of jawless fish that diverged from jawed vertebrates more than half a billion years ago. Lampreys, in particular, are regarded as a model system for the study of ancestral vertebrate-specific traits, though they also have developed lineage-specific features. Genetics, genomics and biochemistry of serpins from basal vertebrates may provide important insights into the emergence and regulation of the endothelium-lined haemostatic system and the pump-driven pressurised circulation that are characteristic for these metazoans. Recent studies indicate that heparin cofactor II (HCII), SpnV4_1 and angiotensinogen are early appearing regulators of coagulation and blood pressure modulation, respectively, in vertebrates. Cartilaginous fish possess almost all serpins characteristic for the advanced haemostatic control system of tetrapods, thus dating emergence of a nearly fully developed inhibitor ensemble to the base of gnathostomes. The conservation of exon-intron organisation of serpin genes from lampreys to mammals provides strong support for the gene structure-based classification of vertebrate serpins. |
