Related Experiment Video
Updated: Apr 13, 2026
11:36
Simple Method for Fluorescence DNA In Situ Hybridization to Squashed Chromosomes
Published on: January 6, 2015
19.0K
Dosage compensation in Drosophila
John C Lucchesi1, Mitzi I Kuroda2
1Department of Biology, O. W. Rollins Research Center, Emory University, Atlanta, Georgia 30322.
Cold Spring Harbor Perspectives in Biology
|May 3, 2015
Summary
Dosage compensation in Drosophila ensures equal gene expression between sexes. The male-specific lethal (MSL) complex, guided by noncoding RNAs, targets the X chromosome, increasing male gene transcription.
Area of Science:
- Epigenetics
- Molecular Biology
- Genetics
Background:
- Dosage compensation equalizes X-linked gene expression between male (XY) and female (XX) Drosophila.
- The male-specific lethal (MSL) complex is crucial for this process, primarily through histone acetylation.
- Understanding MSL complex targeting is key to comprehending epigenetic regulation.
Purpose of the Study:
- To investigate the mechanism of MSL complex targeting and spreading on the Drosophila male X chromosome.
- To elucidate the role of noncoding RNAs in MSL complex assembly and function.
Main Methods:
- Analysis of histone acetylation patterns.
- Investigating the function of noncoding RNAs in MSL complex assembly.
- Studying the spreading of the MSL complex along the X chromosome.
Main Results:
- The MSL complex targets specific sites and spreads across the male X chromosome.
- Two noncoding RNAs are essential for MSL complex assembly.
- These noncoding RNAs facilitate the spreading of the MSL complex to active genes.
Conclusions:
- Noncoding RNAs are critical for the assembly and targeted spreading of the MSL complex.
- This mechanism ensures dosage compensation by increasing male X chromosome transcription.
Related Concept Videos
02:50Dosage Compensation
7.9K
In animals, gender is determined by the number and type of sex chromosome. For example, human females have two X chromosomes, and males have one X and one Y chromosome, whereas C.elegans with one X chromosome is a male, and the one with two X chromosomes is a hermaphrodite.
In addition to sexual development, the X chromosome has genes involved in autosomal functions such as brain development and the immune system. Therefore, males and females with distinct numbers of X chromosomes will...
In addition to sexual development, the X chromosome has genes involved in autosomal functions such as brain development and the immune system. Therefore, males and females with distinct numbers of X chromosomes will...
7.9K
02:45The Ratio of X Chromosome to Autosomes
10.1K
In most organisms, sex is determined by the ratio of X and Y chromosomes. However, in some organisms, such as Drosophila and C.elegans, sex is determined by the ratio of the number of X chromosomes to the number of sets of autosomes. The Y chromosome in Drosophila is active but does not determine sex. It contains genes responsible for the production of sperms in adult flies.
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female...
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female...
10.1K
02:32Position-effect Variegation
7.3K
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.
7.3K
02:04Polytene Chromosomes
11.4K
Polytene chromosomes are giant interphase chromosomes with several DNA strands placed side by side. They were discovered in the year 1881 by Balbiani in salivary glands, intestine, muscles, malpighian tubules, and hypoderm of larvae Chironomus plumosus. Hence, these are also called "Salivary gland chromosomes." These are found in insects of the order Diptera and Collembola; in certain organs of mammals; and synergids, antipodes of flowering plants. Polytene chromosomes are also...
11.4K
02:32Exon Recombination
4.3K
The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes.
Exon shuffling follows “splice frame rules.” Each exon...
Exon shuffling follows “splice frame rules.” Each exon...
4.3K
02:08Gene Conversion
10.9K
Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new...
10.9K