The sea lamprey is an ancient, parasitic fish that invaded the Great Lakes a century ago, where it triggered the collapse of many fisheries. Like many fishes, this species relies on chemical cues to mediate key aspects of its life, including migration and reproduction. Here we report the discovery of a multicomponent steroidal pheromone that is released by stream-dwelling larval lamprey and gui...

In this study we examined the spatial relationship of GABA-containing and GnRH-containing neurons by immunocytochemistry and in situ hybridization in larval and adult brains of sea lamprey, Petromyzon marinus. In immunocytochemical studies, GABA-containing neurons were detected early in lamprey development, by day 20 post-fertilization. At this time point, one population of GABA-containing neur...

Jawless vertebrates are pivotal representatives for studies of the evolution of adaptive immunity due to their unique position in chordate phylogeny. Lamprey and hagfish, the extant jawless vertebrates, have an alternative lymphocyte-based adaptive immune system that is based on somatically diversifying leucine-rich repeat (LRR)-based antigen receptors, termed variable lymphocyte receptors (VLR...

Dorsoventral (DV) specification is a crucial step for the development of the vertebrate telencephalon. Clarifying the origin of this mechanism will lead to a better understanding of vertebrate central nervous system (CNS) evolution. Based on the lamprey, a sister group of the gnathostomes (jawed vertebrates), we identified three lamprey Hedgehog (Hh) homologues, which are thought to play centra...

Agnathan lampreys retain ancestral characteristics of vertebrates in the morphology of skeletal muscles derived from two mesodermal regions: trunk myotomes and unsegmented head mesoderm. During lamprey development, some populations of myoblasts migrate via pathways that differ from those of gnathostomes. To investigate the evolution of skeletal muscle differentiation in vertebrates, we characte...

environmental pollutions and deterioration of spawning grounds have threatened the caspian lamprey. these problems have led to the need for special protection of the species in many localities, nevertheless, there is surprisingly few information about the physiology of caspian lamprey. thus, the present study aimed to evaluate the correlations between blood serum biochemical parameters and gona...

The parasitic sea lamprey (Petromyzon marinus) has caused extensive losses to commercial fish stocks of the upper Great Lakes of North America. Methods of controlling the sea lamprey include trapping, barriers to prevent migration, and use of a chemical lampricide (3-trifluoromethyl-4-nitrophenol) to kill the filter-feeding larvae. Concerns about the non-specificity of these methods have prompt...

The sea lamprey (Petromyzon marinus) is an ancient jawless fish phyletically removed from modern (teleost) fishes. It is an excellent organism in the study of olfaction due to its accessible olfactory pathway, which is susceptible to manipulation, and its important location in the evolution of vertebrates. There are many similarities in the olfactory systems of all fishes, and they also share c...

The influence of the superoxide-generating system, xanthine oxidase, on the release of iron from various vertebrate ferritins was determined both in the presence and absence of superoxide dismutase. The initial rate of iron release in the presence of this system was higher for ferritins from human, trout and rat liver than for those from lamprey liver and horse spleen. The proportion of this ir...

Lampreys are extant representatives of agnathans. Descriptions of lamprey development, physiology and genome have provided critical insights into early evolution of vertebrate traits. However, efficient means for genetic manipulation in agnathan species have not been developed, hindering functional studies of genes in these important Evo-Devo models. Here, we report a CRISPR/Cas system optimize...