在蝶眼斑的定量变化中Distal-less的贡献
Patrícia Beldade1, Paul M Brakefield, Anthony D Long
1Institute of Evolutionary and Ecological Sciences, University of Leiden, PO Box 9516, 2300 RA Leiden, The Netherlands. pbeldade@rulsfb.leidenuniv.nl
Nature
|January 18, 2002
概括
蝶翅膀的颜色模式是研究进化和发展的关键. 研究人员发现,在Bicyclus anynana蝶中,Distal-less基因和眼球大小的DNA变异之间存在联系.
科学领域:
- 进化发育生物学 进化发育生物学
- 遗传学 是一个遗传学.
- 动物颜色动物的颜色.
背景情况:
- 蝶翅膀的颜色图案,特别是眼球,是研究进化选择和发育过程之间的相互作用的优秀模型.
- 热带蝶Bicyclus anynana是眼球研究的焦点物种,因为它具有可量化的形态变异.
- 虽然发育途径与眼球形成有关,但驱动定量变异的特定基因仍未确定.
研究的目的:
- 为了将遗传变异与蝶翅膀图案的进化联系起来.
- 为了确定有助于Bicyclus anynana眼球形态学的定量变异的特定基因.
- 弥合了研究翅膀模式进化和发育中的基因表达之间的差距.
主要方法:
- 在涉及的发育途径中研究候选基因中的DNA多态性.
- 专注于远距离无 (Dll) 基因,它是尾发育的关键参与者.
- 分析了Dll的遗传变异与B. anynana的眼球大小之间的关联.
主要成果:
- 证明了远距离无 (Dll) 基因中的DNA多态性和眼球大小变异之间的显著联系.
- 提供了第一个将特定基因与蝶翅膀特征的定量变异联系起来的遗传证据.
- 确定了DLL作为一个候选基因,影响眼球形态的适应性进化.
结论:
- 远距离无 (Dll) 基因可能是眼球大小定量变异的贡献者,使其成为自然选择的目标.
- 这项研究在进化发育生物学背景下提供了基因型和表型之间的关键联系.
- 进一步的研究可以在这些发现的基础上阐明复杂的适应性特征的遗传结构.
相关概念视频
01:21Frequency-dependent Selection
When the fitness of a trait is influenced by how common it is (i.e., its frequency) relative to different traits within a population, this is referred to as frequency-dependent selection. Frequency-dependent selection may occur between species or within a single species. This type of selection can either be positive—with more common phenotypes having higher fitness—or negative, with rarer phenotypes conferring increased fitness.
02:32Position-effect Variegation
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.
02:27Background and Environment Affect Phenotype
Although the genetic makeup of an organism plays a major role in determining the phenotype, there are also several environmental factors, such as temperature, oxygen availability, presence of mutagens, that can alter an organism’s phenotype.
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
01:21Testing a Claim about Mean: Unknown Population SD
A complete procedure of testing a hypothesis about a population mean when the population standard deviation is unknown is explained here.
Estimating a population mean requires the samples to be approximately normally distributed. The data should be collected from the randomly selected samples having no sampling bias. There is no specific requirement for sample size. But if the sample size is less than 30, and we don't know the population standard deviation, a different approach is used; instead...
Estimating a population mean requires the samples to be approximately normally distributed. The data should be collected from the randomly selected samples having no sampling bias. There is no specific requirement for sample size. But if the sample size is less than 30, and we don't know the population standard deviation, a different approach is used; instead...