Related Experiment Video
Updated: Apr 13, 2026
07:16
Reverse Genetic Approach to Identify Regulators of Pigmentation using Zebrafish
Published on: March 1, 2022
2.9K
PACAP system evolution and its role in melanophore function in teleost fish skin
João C R Cardoso1, Rute C Félix1, Rute S T Martins1
1Comparative Endocrinology and Integrative Biology, Centre of Marine Sciences, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
Molecular and Cellular Endocrinology
|May 3, 2015
Summary
Pituitary adenylate cyclase-activating polypeptide (PACAP) induces pigment aggregation in tilapia melanophores, a novel function in fish. This effect is mediated by the Pac1a receptor, despite paradoxically increasing cAMP levels.
Area of Science:
- * Endocrinology and cell signaling research.
- * Investigating pigment cell function in teleost fish.
Background:
- * Pituitary adenylate cyclase-activating polypeptide (PACAP) is known to regulate various physiological processes.
- * Melanophores are pigment-containing cells crucial for camouflage and display in fish.
- * The roles of PACAP receptors, adcyap1r1a (Pac1a) and vipr2a (Vpac2a), in fish melanophores were previously unclear.
Purpose of the Study:
- * To identify the function of PACAP in tilapia melanophores.
- * To elucidate the signaling pathways involved in PACAP-mediated pigment aggregation.
- * To investigate the specific roles of Pac1a and Vpac2a receptors in melanophore function.
Main Methods:
- * Ex-vivo administration of PACAP to tilapia melanophores.
- * Analysis of gene expression for adcyap1r1a and vipr2a under different light conditions.
- * Investigating the effects of PACAP on intracellular cAMP levels and downstream signaling pathways.
Main Results:
- * PACAP induced significant pigment aggregation in tilapia melanophores, a newly identified function.
- * Pac1a and Vpac2a receptors were expressed in melanophores and down-regulated in darkness.
- * PACAP activation of Pac1a paradoxically increased cAMP, typically associated with pigment dispersion, suggesting a complex regulatory mechanism.
Conclusions:
- * PACAP plays a role in pigment aggregation in fish melanophores via the Pac1a receptor.
- * The interaction of Pac1a with Ramp likely modulates cAMP-dependent PKA activity, favoring Ca(2+)/Calmodulin pathways for pigment aggregation.
- * Duplicate PACAP receptor genes in teleosts may have evolved specific roles in skin physiology.
Related Concept Videos
01:19Pigmentation
5.0K
The color of the skin is influenced by a number of pigments, including melanin, carotene, and hemoglobin. Recall that melanin is produced by cells called melanocytes, which are found scattered throughout the stratum basale of the epidermis. The melanin is transferred to the keratinocytes via melanosomes.
Melanin occurs in two primary forms: eumelanin that provides black and brown pigment and pheomelanin that provides red color. Dark-skinned individuals produce more melanin than those with pale...
Melanin occurs in two primary forms: eumelanin that provides black and brown pigment and pheomelanin that provides red color. Dark-skinned individuals produce more melanin than those with pale...
5.0K
01:22Photoreceptors and Visual Pathways
11.2K
At the molecular level, visual signals trigger transformations in photopigment molecules, resulting in changes in the photoreceptor cell's membrane potential. The photon's energy level is denoted by its wavelength, with each specific wavelength of visible light associated with a distinct color. The spectral range of visible light, classified as electromagnetic radiation, spans from 380 to 720 nm. Electromagnetic radiation wavelengths exceeding 720 nm fall under the infrared category,...
11.2K
01:11Channel Rhodopsins
3.5K
Most organisms use photoreceptors to sense and respond to light. Examples of photoreceptors include bacteriorhodopsins and bacteriophytochromes in some bacteria, phytochromes in plants, and rhodopsins in the photoreceptor cells of the vertebral retina. The light-sensitive property of these receptors is because of the bound chromophores, such as bilin in the phytochromes and retinal in the rhodopsins.
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...
3.5K
01:25Introduction to the Integumentary System
16.5K
The integumentary system is the organ system that comprises the skin and its associated structures. It is the largest system in the human body and plays a crucial role in protecting and maintaining homeostasis. The integumentary system serves several functions including protection, regulation, sensation, and secretion.
The skin, which is the primary organ of the integumentary system, consists of three main layers: the epidermis, dermis, and hypodermis (subcutaneous tissue). The epidermis is the...
The skin, which is the primary organ of the integumentary system, consists of three main layers: the epidermis, dermis, and hypodermis (subcutaneous tissue). The epidermis is the...
16.5K
02:37Gene Duplication and Divergence
8.3K
The seminal work of Ohno in 1970 popularized the idea of gene duplication and divergence. DNA sequence comparison studies reveal that a large portion of the genes in bacteria, archaebacteria, and eukaryotes was generated by gene duplication and divergence, indicating its critical role in evolution.
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are...
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are...
8.3K