Video Experimental Relacionado
Updated: Mar 18, 2026

11:52
Analysis of LINE-1 Retrotransposition at the Single Nucleus Level
Published on: April 23, 2016
8.9K
Pruebas de Dios. El milagro: desenterrar un trasposón RAG
1Department of Microbiology and Immunology, University of Maryland Baltimore, 685 West Baltimore St., Suite 380, Baltimore, MD 21201, USA.
Cell
|July 2, 2016
Resumen
Los investigadores descubrieron ProtoRAG en Amphioxus, un elemento transponible relacionado con el transposón RAG. Este hallazgo arroja luz sobre los orígenes evolutivos de la reorganización génica en los vertebrados con mandíbula.
Área de la Ciencia:
- Biología evolutiva
- Genética molecular
- Inmunología
Sus antecedentes:
- La diversidad de anticuerpos y receptores de células T en vertebrados con mandíbula surge de la reorganización genética.
- Este proceso está mediado por las enzimas RAG1 y RAG2, que se supone que se originan a partir de un elemento transponible (TE).
- La historia evolutiva de estas enzimas RAG y sus orígenes TE sigue siendo incompletamente entendida.
Objetivo del estudio:
- Investigar los orígenes evolutivos de las enzimas RAG1 y RAG2.
- Identificar posibles elementos ancestrales transponibles relacionados con el transposón RAG en los primeros cordados.
Principales métodos:
- Análisis bioinformático de los datos genómicos de los cordados inferiores.
- Identificación y caracterización de nuevos elementos genéticos.
Principales resultados:
- Descubrimiento de ProtoRAG en el cordado inferior de Amphioxus.
- ProtoRAG se identifica como un elemento transponible (TE) homólogo al transposón RAG.
- Esto representa el precursor evolutivo largamente buscado de los genes RAG.
Conclusiones:
- ProtoRAG proporciona información crucial sobre el origen mediado por TE del sistema RAG.
- Los hallazgos iluminan la evolución temprana de la inmunidad adaptativa en los vertebrados.
Videos de Conceptos Relacionados
LTR Retrotransposons
20.3K
LTR retrotransposons are class I transposable elements with long terminal repeats flanking an internal coding region. These elements are less abundant in mammals compared to other class I transposable elements. About 8 percent of human genomic DNA comprises LTR retrotransposons. Some of the common examples of LTR retrotransposons are Ty elements in yeast and Copia elements in Drosophila.
The internal coding region of LTR retrotransposons and their mechanism of transposition closely resembles a...
The internal coding region of LTR retrotransposons and their mechanism of transposition closely resembles a...
20.3K
DNA-only Transposons
18.1K
DNA-only transposons are called autonomous transposons since they code for the enzyme transposase that is required for the transposition mechanism. Insertion of transposons can alter gene functions in multiple ways. They can mutate the gene, alter gene expression by introducing a novel promoter or insulator sequence, introduce new splice sites, and change the mRNA transcripts produced, or remodel chromatin structure.
The donor site from where the transposon is excised is either degraded or...
The donor site from where the transposon is excised is either degraded or...
18.1K
Overview of Transposition and Recombination
20.4K
Transposons make up a significant part of genomes of various organisms. Therefore, it is believed that transposition played a major evolutionary role in speciation by changing genome sizes and modifying gene expression patterns. For example, in bacteria, transposition can lead to conferring antibiotic resistance. Movement of transposable elements within the genetic pool of pathogenic bacteria can aid in transfer of antibiotic-resistant genetic elements. In eukaryotes, transposons can carry out...
20.4K
Non-LTR Retrotransposons
13.9K
As the name suggests, non-LTR retrotransposons lack the long terminal repeats characteristic of the LTR retrotransposons. Additionally, both LTR and non-LTR retrotransposons use distinct mechanisms of mobilization. Non-LTR retrotransposons are further divided into two classes - Long interspersed nuclear elements (LINEs) and short interspersed nuclear elements (SINEs), both of which occur abundantly in most mammals, including humans. Some of the active non-LTR retrotransposons in humans are L1...
13.9K
Transposons
2.8K
Transposons, or "jumping genes," are small mobile genetic elements (MGEs) that range from 700 to 40,000 base pairs in length. They are found in all organisms and can move within the same chromosome or transfer to different chromosomes. In some cases, transposons can also jump between different host DNA molecules, such as plasmids or viruses, contributing to genetic variability.Barbara McClintock first discovered these mobile genetic elements in the 1940s while studying maize genetics, and she...
2.8K
Retroviruses
15.6K
Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’...
15.6K

