在昆虫模式形成的进化过程中,甚至跳过的角色在变化
N H Patel1, E E Ball, C S Goodman
1Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley 94720.
Nature
|May 28, 1992
概括
昆虫的发育在长生殖带 (Drosophila) 和短生殖带 () 模式之间有所不同. 对于Drosophila细分来说至关重要的,甚至跳过的基因在虫中不起对规则基因的作用,揭示了不同的发育途径.
科学领域:
- 发育生物学是发展生物学.
- 进化发育生物学 进化发育生物学
- 遗传学 是一个遗传学.
背景情况:
- 昆虫的发育表现出不同的模式,包括长生殖带 (例如,Drosophila) 和短生殖带 (例如,).
- 分段模式的建立在这些模式之间有很大的差异,可以在分子层面上观察到.
- 分段极性基因和同源基因腹部-A显示与生殖带类型相关的明显表达模式.
研究的目的:
- 研究昆虫生殖带发育差异的分子基础.
- 描述在虫发育过程中甚至跳过基因同类的功能.
- 为了比较在昆虫群体早期细分和后期神经发生过程中,偶跳过的作用.
主要方法:
- 克隆Drosophila对规则基因的同类,甚至跳过.
- 在胚胎发育过程中对基因表达模式的比较分析.
- 功能性研究,以评估偶跳过在细分和神经发生中的作用.
主要成果:
- 在早期胚胎细分过程中,甚至跳过的草同类基因不作为对规则基因起作用.
- 与Drosophila不同的是,在虫中,均跳过的表达不建立初始的对规则模式.
- 同时跳过的基因在Drosophila和虫中都在神经发生过程中保留了保留的功能.
结论:
- 偶跳过的对规则函数是特定于长生殖带昆虫,如Drosophila.
- 短生殖带昆虫利用替代的分子机制进行早期细分.
- 尽管在早期发育过程中存在差异,但在以后的发育过程中,如神经发生学,存在对偶跳过的保留角色.
相关概念视频
01:07Speciation Rates
Speciation can proceed at markedly different rates, and evolutionary biologists commonly describe these differences through the models of gradualism and punctuated equilibrium. Both patterns explain how new species arise, but they differ in the tempo and continuity of evolutionary change. In both cases, evolutionary change arises from heritable variation within populations, with natural selection often shaping traits that improve survival and reproduction under specific environmental conditions.
01:32What is Natural Selection?
Natural selection is an evolutionary process in which individuals with survival-promoting traits reproduce at higher rates. These favorable traits become more common within a population or species. Naturally selected traits initially arise via random genetic mutations. In order for selection to occur, there must be variation within a population, the trait controlling the variation must be heritable, and there must be an evolutionary advantage for variation in the trait.The Theory of Natural...
01:09Mutation, Gene Flow, and Genetic Drift
In a population that is not at Hardy-Weinberg equilibrium, the frequency of alleles changes over time. Therefore, any deviations from the five conditions of Hardy-Weinberg equilibrium can alter the genetic variation of a given population. Conditions that change the genetic variability of a population include mutations, natural selection, non-random mating, gene flow, and genetic drift (small population size).Mechanisms of Genetic VariationThe original sources of genetic variation are mutations,...
01:38Limits to Natural Selection
Organisms that are well-adapted to their environment are more likely to survive and reproduce. However, natural selection does not lead to perfectly adapted organisms. Several factors constrain natural selection.For one, natural selection can only act upon existing genetic variation. Hypothetically, redtusks may enhance elephant survival by deterring ivory-seeking poachers. However, if there are no gene variants—or alleles—for redtusks, natural selection cannot increase the prevalence of...
03:33Genetic Drift
Natural selection—probably the most well-known evolutionary mechanism—increases the prevalence of traits that enhance survival and reproduction. However, evolution does not merely propagate favorable traits, nor does it always benefit populations.Life is not fair. A deer grazing contentedly in a field can have her meal cut tragically short by a bolt of lightning. If the doomed doe is one of only three in the population, 1/3 of the population’s gene pool is lost. Random events like this can...
01:24Evolution of New Traits in Microbes
Microorganisms evolve rapidly due to their large population sizes and short generation times, often exhibiting measurable changes within days under laboratory conditions. Natural selection acts on standing genetic variation, enabling the retention and amplification of beneficial traits that confer fitness advantages in changing environments.Adaptive Pigment Regulation in RhodobacterIn Rhodobacter, a genus of purple non-sulfur bacteria, light-harvesting pigments such as bacteriochlorophyll and...