Video Experimental Relacionado
Updated: Jul 29, 2026
13:30
A New Screening Method for the Directed Evolution of Thermostable Bacteriolytic Enzymes
Published on: November 7, 2012
Evolución adaptativa episódica de las lisozimas de primates.
1Department of Biological Sciences, University at Albany, State University of New York, 12222, USA.
Nature
|January 9, 1997
Resumen
Los investigadores demostraron rigurosamente la evolución adaptativa de las proteínas mediante la identificación de la selección darwiniana positiva en los lisocitos. Este estudio revela episodios específicos de selección adaptativa y purificadora en la evolución de las proteínas de los mamíferos.
Área de la Ciencia:
- Biología evolutiva Biología evolutiva.
- Evolución molecular de la evolución molecular.
- La bioquímica es la bioquímica.
Sus antecedentes:
- Demostrar la importancia adaptativa de las diferencias de aminoácidos en proteínas homólogas entre especies ha sido un desafío.
- Los métodos existentes para detectar la selección darwiniana positiva en proteínas incluyen la convergencia de secuencias y la violación de la tasa neutral.
Objetivo del estudio:
- Para demostrar rigurosamente la importancia adaptativa de las diferencias de aminoácidos entre proteínas homólogas.
- Para combinar las pruebas de violación de la tasa neutral con la reconstrucción de la secuencia ancestral para identificar eventos de selección positiva.
- Investigar la evolución adaptativa en los lisozimas de los mamíferos y hominoides que fermentan el intestino.
Principales métodos:
- Utilizó pruebas de violación de la tasa neutral.
- Secuencias de proteínas ancestrales reconstruidas.
- Analizó lisozimas de vacas y monos langur, y lisozimas hominoides.
Principales resultados:
- Se ha documentado una selección positiva en el linaje que conduce al antepasado común de los monos colobinos con fermentación en el intestino anterior.
- Se detectó un episodio adaptativo no reconocido previamente en el linaje que conduce a los lisozimas hominoides modernos.
- Se observaron episodios posteriores de selección negativa después de ambos eventos adaptativos.
Conclusiones:
- El enfoque combinado detecta efectivamente los episodios de selección adaptativa y purificadora.
- Se pueden localizar linajes específicos durante la evolución de las proteínas para estos eventos de selección.
- Proporciona un método robusto para estudiar la adaptación molecular en las proteínas.
Videos de Conceptos Relacionados
00:36Viral Mutations
A mutation is a change in the sequence of bases of DNA or RNA in a genome. Some mutations occur during replication of the genome due to errors made by the polymerase enzymes that replicate DNA or RNA. Unlike DNA polymerase, RNA polymerase is prone to errors because it is not capable of “proofreading” its work. Viruses with RNA-based genomes, like HIV, therefore accrue mutations faster than viruses with DNA-based genomes. Because mutation and recombination provide the raw material for adaptive...
02:05Gene Evolution - Fast or Slow?
The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain crucial regulatory sequences, the vast majority of this DNA serves no known function. Typically, these regions of the genome are the ones in which the fastest change, in evolutionary terms, is observed, because there is typically little to no selection pressure acting on these regions to preserve their sequences.
In contrast, regions which code...
In contrast, regions which code...
01:31Lysosomes
Lysosomes are membrane-enclosed spherical sacs derived from the Golgi apparatus. The most important function of the lysosome is degrading macromolecules and biological polymers that are released during membrane trafficking events such as the secretory, endocytic, autophagic, and phagocytic pathways. The degradation is carried out by several hydrolytic enzymes active in an acidic environment of the lysosomal lumen. These acid hydrolases are involved in cellular processes such as cell signaling,...
01:22Lysosomal Hydrolases
Lysosomes are the site for the degradation of macromolecules and biological polymers released during membrane trafficking events such as secretory, endocytic, autophagic, and phagocytic pathways. The membrane-enclosed area of the lysosome, called the lumen, contains hydrolytic enzymes active in an acidic environment. These acid hydrolases are functional at a pH between 4.5 and 5 and are involved in cellular processes such as cell signaling, energy metabolism, restoration of the plasma membrane,...
02:31Synteny and Evolution
John H. Renwick first coined the term “synteny” in 1971, which refers to the genes present on the same chromosomes, even if they are not genetically linked. The species with common ancestry tend to show conserved syntenic regions. Therefore, the concept of synteny is nowadays used to describe the evolutionary relationship between species.
Around 80 million years ago, the human and mice lineages diverged from the common ancestor. During the course of evolution, the ancestral chromosome underwent...
Around 80 million years ago, the human and mice lineages diverged from the common ancestor. During the course of evolution, the ancestral chromosome underwent...
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...