Related Experiment Video
Updated: May 20, 2026
11:54
Microsatellite DNA Genotyping and Flow Cytometry Ploidy Analyses of Formalin-fixed Paraffin-embedded Hydatidiform Molar Tissues
Published on: October 20, 2019
Inheritance of dermatoglyphic asymmetry in 500 Indian pedigrees: complex segregation analysis
Bibha Karmakar1, Ida Malkin, Eugene Kobyliansky
1Indian Statistical Institute, Biological Anthropology Unit, Kolkata, India. bibha@isical.ac.in
Collegium Antropologicum
|July 24, 2012
Summary
Inheritance of dermatoglyphic asymmetry is complex, not fitting Mendelian or environmental models. This study suggests significant genetic influence but no major gene involvement in developmental instability.
Area of Science:
- Human genetics
- Anthropometry
- Developmental biology
Background:
- Quantitative dermatoglyphic traits exhibit asymmetry.
- Asymmetry is often linked to developmental instability.
- Understanding the inheritance of these traits is crucial.
Purpose of the Study:
- To determine the mode of inheritance for quantitative dermatoglyphic asymmetry.
- To analyze the genetic basis of asymmetry using principal factors.
- To investigate the relationship between asymmetry and developmental instability.
Main Methods:
- Complex segregation analysis (genetic model fitting) was applied.
- A large, ethnically homogeneous sample of 500 Indian pedigrees (2435 individuals) across two generations was used.
- Segregation analysis was performed on principal component 1 of fluctuating asymmetry (PC1_FA).
Main Results:
- Both Mendelian and environmental inheritance models were rejected for PC1_FA (p < 0.001).
- A General model was accepted, indicating significant inheritance but a more complex pattern than Mendelian.
- Familial correlations showed a slight genetic effect, but no evidence of major gene contribution was found.
Conclusions:
- The inheritance of dermatoglyphic asymmetry is complex and does not follow simple Mendelian or environmental patterns.
- While there is a genetic component, major genes are unlikely to be the primary drivers.
- The findings support the concept that fluctuating asymmetry reflects developmental instability in humans.
Related Concept Videos
01:35Pedigree Analysis
Overview
01:35Pedigree Analysis
Overview
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.
01:49Law of Segregation
When crossing pea plants, Mendel noticed that one of the parental traits would sometimes disappear in the first generation of offspring, called the F1 generation, and could reappear in the next generation (F2). He concluded that one of the traits must be dominant over the other, thereby causing masking of one trait in the F1 generation. When he crossed the F1 plants, he found that 75% of the offspring in the F2 generation had the dominant phenotype, while 25% had the recessive phenotype.
01:18Dihybrid Crosses
Overview
02:03Law of Independent Assortment
While Mendel’s Law of Segregation states that the two alleles for one gene are separated into different gametes, a different question of how different genes are inherited remains. For example, is the gene for tall plants inherited with the gene for green peas? Mendel asked this question by experimenting with a dihybrid cross; a cross in which both parents are homozygous for two distinct traits resulting in an F1 generation that are heterozygous for both traits.