Related Experiment Video
Updated: Aug 6, 2026
08:15
Bead Aggregation Assays for the Characterization of Putative Cell Adhesion Molecules
Published on: October 17, 2014
Common genomic structure for the Lepidoptera cadherin-like genes
Yolanda Bel1, Baltasar Escriche
1Genetics Department, University of Valencia, Dr Moliner, 50, 46100, Burjassot, Valencia, Spain.
Gene
|August 15, 2006
Summary
Insect resistance to Bacillus thuringiensis Cry toxins involves a cadherin-like protein. Researchers identified and analyzed the genes encoding these proteins in three Lepidoptera species, revealing a conserved gene structure.
Area of Science:
- Molecular Biology
- Genomics
- Insect Physiology
Background:
- Cadherin-like proteins in Lepidoptera midgut epithelial cells are linked to insect resistance against Bacillus thuringiensis Cry toxins.
- Understanding the genetic basis of this resistance is crucial for developing sustainable pest management strategies.
Purpose of the Study:
- To identify and characterize the genes encoding cadherin-like proteins in three key Lepidoptera species: Ostrinia nubilalis, Helicoverpa armigera, and Bombyx mori.
- To analyze the genomic organization and evolutionary conservation of these resistance-associated genes.
Main Methods:
- Gene identification and sequencing in Ostrinia nubilalis, Helicoverpa armigera, and Bombyx mori.
- Comparative genomic analysis of gene structure, including exon-intron organization.
- In silico analysis of protein products to determine conserved structural features and family classification.
Main Results:
- The identified genes, varying in size (19.6 kb to 41.8 kb), consistently comprise 35 exons and 34 introns.
- Exon sizes were highly conserved across species, while intron sizes showed significant variability.
- Intronic sequences were inserted at homologous positions, and the first intron was located in the 5'-untranslated region, indicating orthology.
- A common GC-rich region in exon 31 and species-specific tandem repeats were identified.
- Transposable elements contributed to the larger gene size in Bombyx mori.
- In silico analysis confirmed a common structure, classifying the proteins within the protocadherin family.
Conclusions:
- The genes encoding Lepidoptera cadherin-like proteins exhibit a highly conserved structure, supporting their orthologous nature.
- This conserved structure is critical for the function of these proteins in insect resistance to Bacillus thuringiensis Cry toxins.
- The findings provide a foundation for further research into the molecular mechanisms of insect-Cry toxin interactions and resistance evolution.
Related Concept Videos
01:25Structure of Cadherins
The cadherins were one of the first cell adhesion molecules discovered; the term “cadherins” is based on their calcium-dependent adhering properties. The first cadherins discovered on the epithelial, neuronal, and placental cells were named E-cadherin, P-cadherin, and N-cadherin, respectively. These classical cadherins share sequence and structural similarities. Other cadherins, including those involved in cell signaling, are grouped into non-classical cadherins. This diversity of cadherins...
01:19Cadherins in Tissue Organization
The cadherins are a superfamily of cell adhesion molecules comprising over 180 variants, with specific tissues expressing a particular combination of cadherin types. Cadherins generally exhibit homophilic binding; i.e., cadherins on one cell bind to cadherins of the same or closely related type on another cell. Thus, cells of the same type have a specific affinity to bind to each other and sort themselves into clusters to form tissues.
Cell Sorting During Development
Cell sorting plays an...
Cell Sorting During Development
Cell sorting plays an...
01:51Lampbrush Chromosomes
In 1882, Flemming observed lampbrush chromosomes (LBC) in salamander eggs. Later in 1892, Rückert observed LBCs in shark egg cells and coined the term "lampbrush chromosomes" because they looked like brushes used to clean kerosene lamps.
LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops resemble the...
LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops resemble the...
02:32Exon Recombination
The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes.
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Exon shuffling follows “splice frame rules.” Each exon has three reading...
02:02Cis-regulatory Sequences
Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are...
02:02Cis-regulatory Sequences
Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are...