Related Experiment Video
Updated: Jul 12, 2026
10:15
Light Sheet-based Fluorescence Microscopy of Living or Fixed and Stained Tribolium castaneum Embryos
Published on: April 28, 2017
Extra-large Tribolium confusum: a new autosomal recessive mutant
Canadian Journal of Genetics and Cytology. Journal Canadien De Genetique Et De Cytologie
|December 1, 1975
Summary
A newly discovered extra-large (xl) Tribolium confusum mutant exhibits significantly increased pupal weight and generation time due to a prolonged larval stage. This genetic mutation also reduces adult longevity in the flour beetle.
Area of Science:
- Entomology
- Genetics
- Insect Physiology
Background:
- Tribolium confusum (Jacquelin duVal) is a model organism in entomological research.
- Mutational analysis is crucial for understanding insect development and physiology.
Purpose of the Study:
- To characterize a newly identified autosomal recessive mutant, extra-large (xl), in Tribolium confusum.
- To evaluate the phenotypic effects of the xl mutation on growth, development, and longevity.
Main Methods:
- Isolation of the xl mutant through mating competition tests with wild-type and red-eye strains.
- Genetic crosses to determine the mode of inheritance (autosomal recessive).
- Measurement of pupal weight, generation time, and adult longevity under controlled environmental conditions.
Main Results:
- The xl mutant displays approximately doubled pupal weights in both sexes compared to wild-type.
- Generation time is extended to 8-9 weeks, primarily due to a longer larval stage.
- Adult longevity is reduced in xl males (8.5 weeks) and females (6.0 weeks) at 26.7°C and 60% RH.
Conclusions:
- The extra-large (xl) mutation in Tribolium confusum is an autosomal recessive gene associated with subvital effects.
- This mutation significantly impacts developmental timing and body size, with trade-offs in longevity.
Related Concept Videos
01:35Pedigree Analysis
Overview
01:39Epistasis
In addition to multiple alleles at the same locus influencing traits, numerous genes or alleles at different locations may interact and influence phenotypes in a phenomenon called epistasis. For example, rabbit fur can be black or brown depending on whether the animal is homozygous dominant or heterozygous at a TYRP1 locus. However, if the rabbit is also homozygous recessive at a locus on the tyrosinase gene (TYR), it will have an unshaded coat that appears white, regardless of its TYRP1...
02:27Trihybrid Crosses
Trihybrid Crosses
Some of Mendel’s crosses examined three pairs of contrasting characteristics. Such a cross is called a trihybrid cross. A trihybrid cross is a combination of three individual monohybrid crosses. For example, plant height (tall vs. short), seed shape (round vs. wrinkled), and seed color (yellow vs. green).
The F1 generation plants of a trihybrid cross are heterozygous for all three traits and produce eight gametes. Upon self-fertilization, these gametes have an equal chance to...
Some of Mendel’s crosses examined three pairs of contrasting characteristics. Such a cross is called a trihybrid cross. A trihybrid cross is a combination of three individual monohybrid crosses. For example, plant height (tall vs. short), seed shape (round vs. wrinkled), and seed color (yellow vs. green).
The F1 generation plants of a trihybrid cross are heterozygous for all three traits and produce eight gametes. Upon self-fertilization, these gametes have an equal chance to...
02:41Lethal Alleles
Agouti: A Lethal Allele
Lucien Cuénot discovered lethal alleles in 1905 while studying the inheritance of coat color in mice. The agouti gene is responsible for the color of the coat in mice. This gene codes for an agouti-signaling protein, which is responsible for melanin distribution in mammals. The wild-type allele gives rise to gray-brown coat color in mice, while the mutant allele gives rise to yellow coat color. In addition to coat color, the agouti gene is associated with the yellow...
Lucien Cuénot discovered lethal alleles in 1905 while studying the inheritance of coat color in mice. The agouti gene is responsible for the color of the coat in mice. This gene codes for an agouti-signaling protein, which is responsible for melanin distribution in mammals. The wild-type allele gives rise to gray-brown coat color in mice, while the mutant allele gives rise to yellow coat color. In addition to coat color, the agouti gene is associated with the yellow...