G protein-coupled receptor gpr34l mutation affects thrombocyte function in zebrafish.
Seongcheol Kim1, Abdullah Alsrhani1, Lala Zafreen1
1Department of Biological Sciences, University of North Texas, Denton, TX, USA.
British Journal of Haematology
|December 23, 2017
Summary
A novel gene, G protein-coupled receptor 34 like (gpr34l), is crucial for haemostasis. Mutations in gpr34l disrupt thrombocyte function, leading to prolonged clotting times and potential bleeding disorders.
Area of Science:
- Genetics
- Haemostasis
- Molecular Biology
Background:
- Haemostasis is a vital defense mechanism against fluid loss.
- Zebrafish are a valuable model for studying haemostasis genetics.
- Identifying novel genes involved in haemostasis is critical for understanding bleeding disorders.
Purpose of the Study:
- To identify novel genes regulating haemostasis using a zebrafish model.
- To characterize the function of the orphan G protein-coupled receptor 34 like gene (gpr34l) in haemostasis.
Main Methods:
- Zebrafish mutagenesis screening and laser injury venous thrombosis assay to identify mutants with prolonged time to occlusion (TTO).
- Linkage analysis and fine mapping to identify the causative gene mutation.
- RNA rescue experiments and Vivo-Morpholino knockdown to confirm gene function.
- Measurement of cyclic adenosine monophosphate (cAMP) levels in thrombocytes.
Main Results:
- A zebrafish mutant with a prolonged TTO was identified.
- Fine mapping revealed a mutation in the gpr34l gene (Val to Glu substitution).
- gpr34l RNA injection rescued the prolonged TTO defect.
- Mutant thrombocytes exhibited elevated cAMP levels, indicating defective function.
- gpr34l knockdown phenocopied the gpr34l mutation, confirming its role.
Conclusions:
- The orphan G protein-coupled receptor 34 like (gpr34l) is essential for normal haemostasis in zebrafish.
- Loss of functional gpr34l leads to elevated thrombocyte cAMP levels.
- Elevated cAMP impairs thrombocyte aggregation, resulting in prolonged clotting times.
