Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Lecture

Genetic Distance Calculation: Loci Analysis

In course

BIO-105: Cellular biology and biochemistry for engineers

Basic course in biochemistry as well as cellular and molecular biology for non-life science students enrolling at the Master or PhD thesis level from various engineering disciplines. It reviews essential notions necessary for a training in biology-related ...

Description

This lecture covers the measurement of genetic distance between two loci, focusing on the black locus for body color and the vestigial locus for wing size. Through the analysis of phenotypes and recombination frequencies, students learn how to calculate genetic distances and detect linkage in genetic crosses.

Instructor

Romain Zufferey

Official source

Related concepts (22)

Genetic linkage

Genetic linkage is the tendency of DNA sequences that are close together on a chromosome to be inherited together during the meiosis phase of sexual reproduction. Two genetic markers that are physically near to each other are unlikely to be separated onto different chromatids during chromosomal crossover, and are therefore said to be more linked than markers that are far apart. In other words, the nearer two genes are on a chromosome, the lower the chance of recombination between them, and the more likely they are to be inherited together.

Human genetic variation

Human genetic variation is the genetic differences in and among populations. There may be multiple variants of any given gene in the human population (alleles), a situation called polymorphism. No two humans are genetically identical. Even monozygotic twins (who develop from one zygote) have infrequent genetic differences due to mutations occurring during development and gene copy-number variation. Differences between individuals, even closely related individuals, are the key to techniques such as genetic fingerprinting.

Genetic history of Europe

The genetic history of Europe includes information around the formation, ethnogenesis, and other DNA-specific information about populations indigenous, or living in Europe. The most significant recent dispersal of modern humans from Africa gave rise to an undifferentiated "non-African" lineage by some 70–50 ka (70-50,000 years ago). By about 50–40 ka a West Eurasian lineage had emerged, as had a separate East Eurasian lineage. Both East and West Eurasians acquired Neanderthal admixture in Europe and Asia.

Genetic recombination

Genetic recombination (also known as genetic reshuffling) is the exchange of genetic material between different organisms which leads to production of offspring with combinations of traits that differ from those found in either parent. In eukaryotes, genetic recombination during meiosis can lead to a novel set of genetic information that can be further passed on from parents to offspring.

Quantitative trait locus

A quantitative trait locus (QTL) is a locus (section of DNA) that correlates with variation of a quantitative trait in the phenotype of a population of organisms. QTLs are mapped by identifying which molecular markers (such as SNPs or AFLPs) correlate with an observed trait. This is often an early step in identifying the actual genes that cause the trait variation. A quantitative trait locus (QTL) is a region of DNA which is associated with a particular phenotypic trait, which varies in degree and which can be attributed to polygenic effects, i.

Related lectures (30)

Genetic Distance: Locus Interactions in Drosophila Melanogaster

Explores genetic distance calculation in Drosophila melanogaster through dihybrid test crosses and recombination frequencies.

Genetic Inheritance: Dihybrid Crosses and Genetic Distance

Explores genetic inheritance through dihybrid crosses and calculating genetic distances.

Mutations and Genetic Variability

Explores mutations, phenotype effects, environmental influences, meiosis, genetic shuffling, and chromosomal abnormalities.

Patterns of Inheritance in Biology

Explores major themes in biology, patterns of inheritance, Mendel's laws, genetic defects, and the impact of the environment on phenotype.

Genetics: Chromosome Inheritance