Related Experiment Video
Updated: Jul 5, 2025
07:48
Use of Time-Lapse Microscopy and Stage-Specific Nuclear Depletion of Proteins to Study Meiosis in S. cerevisiae
Published on: October 11, 2022
1.8K
Fas2: A Tale of Two Chromosomes
Tara M Finegan1,2, Christian Cammarota3, Oscar Mendoza Andrade2
1Departments of Biology, University of Rochester, Rochester NY, 14627, USA.
Biorxiv : the Preprint Server for Biology
|January 23, 2024
Summary
The cell adhesion molecule Fasciclin II (Fas2) function was clarified by identifying a modifier mutation. The Neuroglian (Nrg) null allele enhances Fas2 loss-of-function phenotypes, explaining discrepancies in previous studies.
Area of Science:
- Developmental Biology
- Cell Adhesion
- Genetics
Background:
- Fasciclin II (Fas2) is a cell-cell adhesion molecule crucial for axon guidance and epithelial cell reintegration.
- Distinct Fas2 null alleles exhibit varying phenotypes, questioning their true loss-of-function status.
- Understanding Fas2 function is vital due to its widespread use in research.
Conclusions:
- The observed differences in Fas2 null allele phenotypes are due to genetic background modifiers.
- The Neuroglian (Nrg) null allele acts as a suppressor of Fas2 function, explaining the milder phenotype of the Fas2 allele.
- This study clarifies the functional consequences of Fas2 mutations and highlights the importance of genetic background in phenotypic analysis.
Related Concept Videos
01:57Meiosis II
183.4K
Meiosis II is the second and final stage of meiosis. It relies on the haploid cells produced during meiosis I, each of which contain only 23 chromosomes—one from each homologous initial pair. Importantly, each chromosome in these cells is composed of two joined copies, and when these cells enter meiosis II, the goal is to separate such sister chromatids using the same microtubule-based network employed in other division processes. The result of meiosis II is two haploid cells, each...
183.4K
02:57Attachment of Sister Chromatids
3.3K
As cells progress into mitosis, the nuclear envelope breaks down, and the condensed chromosomes are exposed to the array of bipolar microtubules of the mitotic spindle. The kinetochore, a large, disc-shaped protein complex, is present at the centromere region of the sister chromatids and acts as a binding site for the microtubules. Usually, the plus-end of a single microtubule is embedded within the kinetochore. However, some kinetochores first establish lateral contact with the side-wall...
3.3K
02:17Separation of Sister Chromatids
3.6K
At the transition from prophase to metaphase, there is a reduction in cohesion along the chromosomal arms, resulting in the resolution of sister chromatids. However, residual cohesin connections remain to hold the sister chromatids together until the transition from metaphase to anaphase. The residual connection prevents any premature separation of sister chromatids, blocking the risks of aneuploidy within the daughter cells.
At the onset of anaphase, separase, a proteolytic enzyme, is...
At the onset of anaphase, separase, a proteolytic enzyme, is...
3.6K
01:49Meiosis I
193.6K
Meiosis is a carefully orchestrated set of cell divisions, the goal of which—in humans—is to produce haploid sperm or eggs, each containing half the number of chromosomes present in somatic cells elsewhere in the body. Meiosis I is the first such division, and involves several key steps, among them: condensation of replicated chromosomes in diploid cells; the pairing of homologous chromosomes and their exchange of information; and finally, the separation of homologous chromosomes by...
193.6K
02:04Polytene Chromosomes
10.0K
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...
10.0K
01:29Nondisjunction
75.6K
During meiosis, chromosomes occasionally separate improperly. This occurs due to failure of homologous chromosome separation during meiosis I or failed sister chromatid separation during meiosis II. In some species, notably plants, nondisjunction can result in an organism with an entire additional set of chromosomes, which is called polyploidy. In humans, nondisjunction can occur during male or female gametogenesis and the resulting gametes possess one too many or one too few chromosomes.
75.6K