Sven Loven Centre for Marine Sciences, Kristineberg, University of Gothenburg, SE-450 34 Fiskebäckskil, Sweden
Department of Biomedicine, Kristianstad University, SE-291 88 Kristianstad, Sweden.
Biol Open. 2015 Jan 16;4(2):206-11. doi: 10.1242/bio.20149993.
Colour change of the skin in lower vertebrates such as fish has been a subject of great scientific and public interest. However, colour change also takes place in eyes of fish and while an increasing amount of data indicates its importance in behaviour, very little is known about its regulation. Here, we report that both eye and skin coloration change in response to white to black background adaptation in live sand goby Pomatoschistus minutes, a bentic marine fish. Through in vitro experiments, we show that noradrenaline and melanocyte concentrating hormone (MCH) treatments cause aggregation of pigment organelles in the eye chromatophores. Daylight had no aggregating effect. Combining forskolin to elevate intracellular cyclic adenosine monophosphate (cAMP) with MCH resulted in complete pigment dispersal and darkening of the eyes, whereas combining prolactin, adrenocorticotrophic hormone (ACTH) or melanocyte stimulating hormone (α-MSH) with MCH resulted in more yellow and red eyes. ACTH and MSH also induced dispersal in the melanophores, resulting in overall darker eyes. By comparing analysis of eyes, skin and peritoneum, we conclude that the regulation pattern is similar between these different tissues in this species which is relevant for the cryptic life strategy of this species. With the exception of ACTH which resulted in most prominent melanophore pigment dispersal in the eyes, all other treatments provided similar results between tissue types. To our knowledge, this is the first study that has directly analysed hormonal regulation of physiological colour change in eyes of fish.
皮肤颜色变化在鱼类等低等脊椎动物中一直是科学和公众关注的热点。然而，鱼类眼睛的颜色也会发生变化，尽管越来越多的数据表明其在行为中的重要性，但对其调控机制知之甚少。在这里，我们报告活体沙鲷（Pomatoschistus minutes）的眼睛和皮肤颜色会随白色到黑色背景的适应而发生变化，沙鲷是一种底栖海洋鱼类。通过体外实验，我们发现去甲肾上腺素和黑色素细胞集中激素（MCH）处理会导致眼睛色素细胞中的色素颗粒聚集。日光没有聚集作用。将 forskolin 与 MCH 结合使用以提高细胞内环磷酸腺苷（cAMP）水平会导致完全色素分散和眼睛变暗，而将催乳素、促肾上腺皮质激素（ACTH）或黑色素细胞刺激激素（α-MSH）与 MCH 结合使用会导致眼睛呈现更黄和更红的颜色。ACTH 和 MSH 也会诱导黑色素细胞中的色素分散，从而使眼睛整体变暗。通过比较眼睛、皮肤和腹膜的分析，我们得出结论，在这种物种中，这些不同组织之间的调控模式相似，这与其隐蔽的生活策略有关。除了 ACTH 会导致眼睛中黑色素细胞的色素分散最为明显外，所有其他处理在不同组织类型之间提供了相似的结果。据我们所知，这是第一项直接分析鱼类眼睛中生理颜色变化的激素调控的研究。
