Related Experiment Video
Updated: Jul 6, 2026
09:38
Direct Reprogramming of Mouse Fibroblasts into Melanocytes
Published on: August 27, 2021
Melanocyte-lineage expression of Cre recombinase using Mitf regulatory elements
Azita Alizadeh1, Karen R Fitch, Colleen M Niswender
1Departments of Genetics and Pediatrics, Stanford University School of Medicine, Stanford, CA, USA.
Pigment Cell & Melanoma Research
|March 21, 2008
Summary
Researchers created new transgenic mice to study pigment cell biology. These mice allow specific gene manipulation in melanocytes, aiding research into pigment production and color changes.
Area of Science:
- Genetics
- Developmental Biology
- Cell Biology
Background:
- Gene expression manipulation in melanocytes is crucial for understanding pigment cell biology.
- The Microphthalmia-associated transcriptional factor (Mitf) gene plays a key role in melanocyte development.
Purpose of the Study:
- To develop a tool for specific gene manipulation in melanocyte lineage cells.
- To investigate the role of Protein Kinase A (PKA) signaling in pigment type switching.
Main Methods:
- Constructed transgenic mice using bacterial artificial chromosome (BAC) technology with Cre recombinase under Mitf gene regulatory elements.
- Utilized the Gt(Rosa)26(tm1Sor)(R26R) reporter locus to confirm Cre expression specificity in melanocyte lineage.
- Employed a loxP-targeted allele of the Prkaca gene (CalphaR) to assess PKA signaling activation.
Main Results:
- MitfCre transgene expression was confirmed specifically in melanocyte lineage cells, from embryonic melanoblasts to postnatal skin melanocytes.
- Cre-mediated recombination in the CalphaR allele led to activation of PKA signaling.
- Mice with MitfCre and CalphaR exhibited darker coat color, indicating a shift from pheomelanin to eumelanin synthesis.
Conclusions:
- The MitfCre transgenic mouse line is a valuable tool for studying pigment cell biology.
- PKA signaling is confirmed as a key regulator of pigment type switching (pheomelanin to eumelanin).
- This tool facilitates further investigation into the genetic mechanisms controlling pigmentation.
Related Concept Videos
02:23Master Transcription Regulators
Master transcription regulators are regulatory proteins that are predominantly responsible for regulating the expression of multiple genes. Often these genes work in concert to drive a complex process. Activation of a master transcription regulator can lead to a cascade of transcriptional activation necessary for that outcome. These regulators can directly bind to the regulatory sequences of the various genes involved, or they can indirectly regulate transcription by binding to regulatory...
02:53Conservative Site-specific Recombination and Phase Variation
Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
The recognition sites for Cre recombinase called LoxP...
02:11Reporter Genes
Reporter genes are a type of protein-coding gene that are often tagged to a gene of interest. Once inside a target cell, reporter genes usually produce visually identifiable characteristics like fluorescence and luminescence when expressed along with the gene of interest. Thus, reporter genes “report” the presence or absence of genes of interest in an organism, determine the gene expression pattern, or track the physical location of a DNA segment or protein in the cell.
Commonly used reporter...
Commonly used reporter...
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...