Related Experiment Video
Updated: May 10, 2026
07:54
Manipulation of Ploidy in Caenorhabditis elegans
Published on: March 15, 2018
Genetics: swinging ciliates' seven sexes
1The Donald Danforth Plant Science Center, St. Louis, MO 63132, USA. jumen@danforthcenter.org
Current Biology : CB
|June 8, 2013
Summary
Ciliates exhibit unique nuclear remodeling. Tetrahymena employs a novel roulette-like mechanism for mating type determination, adding to their known reproductive strategies.
Area of Science:
- Cell Biology
- Genetics
- Protozoology
Background:
- Ciliates, such as Tetrahymena, are unicellular eukaryotes known for complex nuclear dimorphism and dynamic genome rearrangements.
- Nuclear remodeling in ciliates is crucial for their life cycle, including sexual reproduction and maintaining genetic integrity.
Purpose of the Study:
- To investigate the mechanism of mating type determination in Tetrahymena.
- To elucidate the "roulette-like" process involved in sexual selection and its genetic basis.
Main Methods:
- Observational studies of Tetrahymena mating.
- Genetic analysis of mating type inheritance.
- Microscopic examination of nuclear behavior during conjugation.
Main Results:
- Tetrahymena utilizes a distinctive, roulette-like system for selecting mating types during sexual reproduction.
- This process involves specific nuclear events that ensure genetic diversity and successful mating.
Conclusions:
- The discovery of the roulette-like mating type choice in Tetrahymena expands our understanding of nuclear remodeling in ciliates.
- This finding highlights the diversity of reproductive strategies in single-celled organisms.
Related Concept Videos
02:45The Ratio of X Chromosome to Autosomes
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 Drosophila...
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
01:43Incomplete Dominance
Gregor Mendel's work (1822 - 1884) was primarily focused on pea plants. Through his initial experiments, he determined that every gene in a diploid cell has two variants called alleles inherited from each parent. He suggested that amongst these two alleles, one allele is dominant in character and the other recessive. The combination of alleles determines the phenotype of a gene in an organism.
02:32X and Y Chromosomes
Among mammals, the gender of an organism is determined by the sex chromosomes. Humans have two sex chromosomes, X and Y. Every human diploid cell has 22 pairs of autosomes and one pair of sex chromosomes. A human female has two X chromosomes, while a male has one X chromosome and one Y chromosome.
The germline cells such as egg and sperm cells carry only half the number of chromosomes, i.e., 22 autosomes and one sex chromosome. All eggs have an X chromosome, while sperm cells can carry an X or...
The germline cells such as egg and sperm cells carry only half the number of chromosomes, i.e., 22 autosomes and one sex chromosome. All eggs have an X chromosome, while sperm cells can carry an X or...
02:19The Y Chromosome Determines Maleness
The Y chromosome is a sex chromosome found in several vertebrates and mammals, including humans. In addition to 22 pairs of autosomes, the human males have one X chromosome and one Y chromosome. In these organisms, the presence or absence of the Y chromosome determines the development of male traits.
Evolution
Around 300 million years ago, the two sex chromosomes diverged from two identical autosomal chromosomes. Over time, the Y chromosome has lost most of its genes, shrinking in size. Today,...
Evolution
Around 300 million years ago, the two sex chromosomes diverged from two identical autosomal chromosomes. Over time, the Y chromosome has lost most of its genes, shrinking in size. Today,...
02:02Cis-regulatory Sequences
Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are...
02:50Dosage Compensation
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 have...
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 have...