洞穴鱼的胰岛素耐药性作为适应营养有限的环境
Misty R Riddle1, Ariel C Aspiras1, Karin Gaudenz2
1Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.
Nature
|March 22, 2018
概括
洞穴鱼因胰岛素受体突变而表现出胰岛素耐药性,这有助于在食物短缺期间生存. 尽管如此,它们仍然保持正常的寿命,这表明它们对缺乏营养的洞穴环境有独特的适应能力.
科学领域:
- 进化生物学
- 生理学
- 遗传学
背景情况:
- 生物面临着周期性食物短缺的挑战,特别是依赖外部能源的洞穴生物.
- 洞穴适应的墨西哥四叶草 (Astyanax mexicanus) 由于环境而缺乏营养.
研究的目的:
- 调查洞穴适应与河流适应的墨西哥四动物的血糖稳定性和胰岛素耐药性.
- 确定导致洞穴鱼和地表鱼代谢差异的遗传因素.
主要方法:
- 在洞穴和河流群体中对血糖稳定性和胰岛素抵抗性的比较分析.
- 在体外评估胰岛素受体结合性.
- 对洞穴鱼种群进行胰岛素受体基因突变的基因分析.
- 携带鉴定突变的杂交和基因工程斑马鱼的表型分析.
主要成果:
- 与河流群体相比,洞穴适应的墨西哥四体表现出血糖稳定性和胰岛素耐药性的失调.
- 在多个洞穴群体中发现了胰岛素受体基因突变,导致胰岛素结合性降低和高血糖.
- 携带胰岛素受体突变的鱼体体重增加,这表明它们在不频繁食时具有适应性优势.
结论:
- 由胰岛素受体突变驱动的胰岛素信号减少似乎有利于在营养有限的洞穴环境中生存.
- 洞穴鱼具有补偿机制,减轻通常与胰岛素抵抗和高血糖相关的负面健康后果.
- 这项研究强调了对极端环境的进化适应,并提供了对新陈代谢调节的见解.
相关概念视频
Limiting Reactant
70.5K
The relative amounts of reactants and products represented in a balanced chemical equation are often referred to as stoichiometric amounts. However, in reality, the reactants are not always present in the stoichiometric amounts indicated by the balanced equation.
70.5K
Absorption of Nutrients
5.7K
Absorption refers to taking dietary nutrients from the intestinal lumen for transportation throughout the body. After digestion in the small intestine, carbohydrates, proteins, and fats are broken down into simpler forms. These essential macronutrients and other vital substances, such as vitamins, minerals, and water, are then prepared for absorption into the bloodstream.
Enterocytes, which are specialized polar epithelial cells, line the mucosa of the small intestinal walls. These cells...
Enterocytes, which are specialized polar epithelial cells, line the mucosa of the small intestinal walls. These cells...
5.7K
The Number e as a Limit
101
The number e is a fundamental constant in calculus, playing a central role in describing continuous change, particularly exponential growth. It is most naturally defined through its relationship with the natural logarithm, which is the inverse of the exponential function with base e. This relationship allows e to be characterized using basic principles of differentiation rather than as an arbitrary numerical constant.A key property of the natural logarithm function, ln x, is that its derivative...
101
Types of Limits I
209
Limits are a key mathematical concept for understanding how functions behave as their input approaches specific values, particularly when the function is undefined. They help reveal trends and discontinuities by examining the values a function approaches rather than its actual value.One-sided limits focus on the direction from which a value is approached. When a function behaves differently depending on whether the input approaches from the left or the right, the two one-sided limits may not...
209
Limit Laws I
233
Limit laws provide essential tools for analyzing how functions behave as their input approaches a specific value. These laws are particularly useful when dealing with combinations of functions, provided the individual limits exist. The Sum and Difference Laws state that the limit of the sum or difference of two functions equals the sum or difference of their respective limits:The Product Law asserts that the limit of the product of two functions equals the product of their individual limits:A...
233
Insulin Secretory Vesicles
7.0K
Insulin secretory vesicles release insulin to stimulate blood glucose uptake and regulate carbohydrate metabolism. When the blood glucose levels increase, glucose enters the pancreatic β-islet cells through glucose transporters. Once inside, glucose is metabolized through glycolysis, the citric acid cycle, and the electron transport chain, producing ATP. This increase in ATP concentration closes ATP-sensitive potassium channels, leading to depolarization of the membrane and the opening of...
7.0K


