About This Project


What are Lampreys and Why do We Study them?

Lampreys are primitive vertebrates that, together with hagfishes, represent the only two extant genera of jawless fish known as the Agnatha. Accumulating fossil evidence has demonstrated that lampreys in the Devonian period are already almost identical to the modern adult lampreys, with well-developed oral disc, annular cartilages, and circumoral teeth, suggesting the evolutionary long-term stability of lampreys.

The life cycle of lampreys typically starts in freshwater, where fertilized eggs hatch into small, wormlike larvae (ammocoetes). Ammocoetes differ significantly from their adults in morphology, and they usually burrow into soft substrates where they filter feed on organic matter. Lampreys remain as larvae for about 2-8 years, which appears to be influenced by factors such as climate and food quality. After metamorphosis, the parasitic phase lampreys migrate into the ocean and feed on the blood and body fluids of the hosts. In the last stage, the non-parasitic phase adult lampreys return to freshwater to spawn and die.

The lamprey genome maintains the most primitive features of vertebrates and has a unique role in the study of origin and evolution; lamprey, as an important developmental evolution model animal, can analyze the evolutionary conservation and derived features of vertebrates; lamprey brain provides the blueprint for the evolution of the mammalian cerebral cortex; in terms of the immune system, lampreys have an adaptive immune system and immune molecules distinct from those of jawed vertebrates. In addition, the unique physiological structure of lamprey gives it an obvious advantage in disease model research. Lamprey has strong functional regeneration ability and can restore normal movement in a short period of time after spinal cord transection. This rare functional feature has important reference value for the treatment of patients with spinal cord injury. Lamprey is the only vertebrate whose gallbladder and bile duct can spontaneously disappear during growth and development. Lamprey has a complete bile duct system in the larval stage, but during metamorphosis, lamprey shows developmental biliary atresia, bile duct and the gallbladder gradually degenerates until the entire biliary system is completely lost. At the same time, liver cells undergo rearrangement and fine structure changes. By exploring the mechanism of bile acid tolerance caused by biliary atresia in lamprey, it is an excellent animal model of biliary atresia.

Considering their unique phylogenetic position, lampreys have become an important model animal to study the early vertebrate evolution, development, adaptive immune origin, developmental neurobiology, and animal physiology.

What is Metabolomics?

Metabolomics is the large-scale study of small molecules, commonly known as metabolites, within cells, biofluids, tissues or organisms. Collectively, these small molecules and their interactions within a biological system are known as the metabolome.

Metabolomics is a powerful approach because metabolites and their concentrations, unlike other “omics” measures, directly reflect the underlying biochemical activity and state of cells / tissues. Thus metabolomics best represents the molecular phenotype.

What is Spatial Metabolomics?

Spatial metabolomics is a field of omics research focused on the detection and interpretation of metabolites in the spatial context of cells, tissues, organs, and organisms.

Techniques for Spatial Metabolomics

Mass spectrometry imaging (MSI) is one of the most noteworthy techniques for spatial metabolomics studies, with the achievable spatial resolution down to cellular and sub-cellular levels to date. While the molecular coverage is typically low and metabolite identification is challenging in MSI. By contrast, although limited in spatial resolution, the LCMS-based spatial metabolomics approach provides unprecedented sensitivity and molecular coverage, thus allowing a more detailed investigation of the biological system. As our objective is not to map the spatial distribution of metabolite in lampreys, we decided to use LCMS to perform a tissue-wide spatial metabolomics analysis. 

Data Availability

Raw datasets have been uploaded in MetaboLights, and they can be freely downloaded here.

Protocol

Our LCMS protocol outlines the method we used to construct our lampreyDB database (https://www.lampreydb.com), and it is designed to provide a step-by-step guide for those who wish to follow our methodology. The protocol includes detailed instructions on the instrumentation and chromatographic conditions used, as well as information on the mass spectrometry parameters and settings. 

If you find LampreyDB helpful, please consider citing the our paperblush:

- M. Gou, X. DuanJ. LiY. Wang, Q. Li, Y. Pang, and Y. Dong. (2023) Spatial Metabolomics Reveals the Multifaceted Nature of Lamprey Buccal Gland and Its Diverse Mechanisms for Blood-Feeding. (PDF)