The objective of the study was to check the health status of the anadromic river lamprey Lampetra fluviatilis (L.), the most frequently recorded lamprey species in Poland caught in Lake Dabie, connected with the Odra river estuary. The species composition of parasitofauna of the river lamprey from the Polish waters was compared to the pathogens of this host noted so far. The skin and fins, eyes...

The appearance of cellular cartilage was a defining event in vertebrate evolution because it made possible the physical expansion of the vertebrate "new head". Despite its central role in vertebrate evolution, the origin of cellular cartilage has been difficult to understand. This is largely due to a lack of informative evolutionary intermediates linking vertebrate cellular cartilage to the ace...

In vitro experiments were conducted to determine the factors contributing to the unusual distribution of CO2 in the blood of the sea lamprey. When rainbow trout red blood cells (RBCs) were equilibrated with a 3 % CO2:nitrogen mixture in either normal saline or sodium-free saline, the extracellular total carbon dioxide content (CCO2ext) was highly dependent upon the fraction of RBCs in the suspe...

A full-length transcript encoding a functional type II GnRH receptor was cloned from the pituitary of the sea lamprey, Petromyzon marinus. The current study is the first to identify a pituitary GnRH receptor transcript in an agnathan, which is the oldest vertebrate lineage. The cloned receptor retains the conserved structural features and amino acid motifs of other known GnRH receptors and nota...

The vertebrate jaw is a mandibular-arch derivative, and is regarded as the synapomorphy that defines the gnathostomes. Previous studies (Kuratani et al., Phil. Trans. Roy. Soc. 356:15, 2001; Shigetani et al., Science 296:1319, 2002) have suggested that the oral apparatus of the lamprey is derived from both the mandibular and premandibular regions, and that the jaw has arisen as a secondary narr...

Structure and vitamin A-storage of the mesangial cells in the lamprey kidney are documented using the gold chloride method, fluorescence histochemistry and electron microscopy. Abundant lipid droplets in the cytoplasm of the mesangial cells release intense, but quickly fading vitamin A-fluorescence under a fluorescence microscope and react with gold chloride. Characteristic tubular invagination...

1. Lamprey fibrinopeptide B is a relatively large peptide made up of about 40 amino acid residues. The peptide is highly electronegative, containing a large number of aspartic acid residues and a tyrosine O-sulphate residue. 2. The amino acid sequence of the first 18 residues from the N-terminal end of fibrinopeptide B has been established. The C-terminal ends with the sequence Val-Arg. Fibrino...

Lampreys, one of the two surviving groups of ancient vertebrates, have become important models for study in diverse fields of biology. Lampreys (of which there are approximately 40 species) are being studied, for example, (a) to control pest sea lamprey in the North American Great Lakes and to restore declining populations of native species elsewhere; (b) in biomedical research, focusing partic...

Lymphocyte-like cells in the intestine of the sea lamprey, Petromyzon marinus, were isolated by flow cytometry under light-scatter conditions used for the purification of mouse intestinal lymphocytes. The purified lamprey cells were morphologically indistinguishable from mammalian lymphocytes. A cDNA library was prepared from the lamprey lymphocyte-like cells, and more than 8,000 randomly selec...

The sea lamprey is a basal, jawless vertebrate that possesses many neural crest derivatives, but lacks jaws and sympathetic ganglia. This raises the possibility that the factors involved in sympathetic neuron differentiation were either a gnathostome innovation or already present in lamprey, but serving different purposes. To distinguish between these possibilities, we isolated lamprey homologu...