Related Experiment Video
Updated: May 11, 2026

Merging Absolute and Relative Quantitative PCR Data to Quantify STAT3 Splice Variant Transcripts
Published on: October 9, 2016
Alternative splice variants of the rainbow trout leptin receptor encode multiple circulating leptin-binding proteins
Ningping Gong1, Ingibjörg E Einarsdottir, Marcus Johansson
1Fish Endocrinology Laboratory, Department of Biological and Environmental Sciences, University of Gothenburg, S-40590 Gothenburg, Sweden. ningping.gong@bioenv.gu.se
Researchers identified novel leptin (Lep) binding proteins (LepBPs) in rainbow trout, which are distinct from those in mammals. These LepBPs, derived from the leptin receptor (LepR) gene, play a role in regulating leptin
Area of Science:
- Endocrinology
- Comparative Physiology
- Molecular Biology
Background:
- Leptin (Lep) binding proteins (LepBPs) are crucial for regulating leptin function in mammals, primarily derived from the leptin receptor (LepR) gene.
- Information regarding LepBPs in nonmammalian vertebrates, particularly fish, remains limited.
Purpose of the Study:
- To characterize multiple LepBPs in rainbow trout (Oncorhynchus mykiss), an early vertebrate model.
- To elucidate the molecular basis and tissue-specific expression of these LepBPs.
Main Methods:
- Size-exclusion chromatography and cross-linking assays to identify Lep-binding proteins.
- Affinity chromatography for LepBP isolation and competitive binding assays for specificity.
- RIA, immunoblotting, and analysis of alternatively spliced LepR transcripts (LepR(S1-3)).
Main Results:
- Plasma proteins bound to Lep ranged from 70 to 100 kDa, identified as LepR isoforms (LepBP1, LepBP2, LepBP3).
- LepR(S1-3) transcripts encode these LepBPs, with distinct tissue expression patterns (LepR(S2) in adipose, LepR(S3) in brain/spleen).
- Plasma LepBP levels decreased after fasting, and hepatic LepR(S3) mRNA increased.
Conclusions:
- Rainbow trout possess a unique mechanism for generating LepBPs, differing from mammals.
- Tissue-specific expression of LepBPs in fish modulates leptin's physiologic actions centrally and peripherally.
- This study provides insights into the evolution of leptin signaling in vertebrates.
Related Concept Videos
RNA Splicing
Alternative RNA Splicing
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
Leaky Scanning
Exon Recombination
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Protein Complexes with Interchangeable Parts
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
Epistasis

