The key difference between haplogroup and haplotype is that haplogroup refers to a group of similar haplotypes that share a common ancestor, while haplotype refers to set of alleles inherited together from generation to generation due to genetic linkage.
A gene primarily consists of two alleles. There are thousands of genes present in chromosomes. When segregating, they show crossovers and genetic recombinations. However, some alleles of genes are located very close to each other. In simple words, these alleles show a genetic linkage. Hence, they are not likely to crossover or recombine. Instead, they always tend to transmit together from generation to generation. Accordingly, a haplotype is a combination of alleles or a set of single nucleotide polymorphisms present on the same chromosome that are inherited together along the generations from a single parent. Haplogroup is a group of similar haplotypes that share a common ancestor.
CONTENTS
1. Overview and Key Difference
2. What is Haplogroup
3. What is Haplotype
4. Similarities Between Haplogroup and Haplotype
5. Side by Side Comparison – Haplogroup vs Haplotype in Tabular Form
6. Summary
What is Haplogroup?
Haplogroup is a group of similar haplotypes that share a common ancestor. In other words, a haplogroup is a combination of alleles present in different chromosomes that are inherited together. These alleles are present very close to each other. The haplotypes in a haplogroup have similar patterns and are related descendants since they have a common ancestor. Thus, it is easy to predict a haplogroup from haplotypes.
Figure 01: Haplogroup
There are two most common haplogroups in human. They are Y chromosome haplogroups that pass from father to son while and mitochondrial DNA haplogroups that pass from mother to daughter or son.
What is Haplotype?
A haplotype is a set of alleles inherited together. These alleles are present in the same chromosome very close to each other because of genetic linkage. Therefore, there is no chance of recombination or crossovers. Hence they pass together from generation to generation. These alleles can be the alleles of a single gene or alleles across multiple genes. A haplotype can also refer to a cluster of single nucleotide polymorphisms present on the same chromosome. Thus, they are a set of DNA variation or polymorphisms inherited together.
Figure 02: Single Nucleotide Polymorphism
Information about haplotypes is useful in investigating the influence of genes on diseases. By analyzing haplotypes and haplotype trees, geneticists can detect the disease-related genome regions and determine the patterns of genetic variation related to diseases. Moreover, they are useful during gene mapping when placing genetic markers in the right places on the chromosomes.
What are the Similarities Between Haplogroup and Haplotype?
- Haplogroup consists of similar haplotypes.
- They show genetic linkages.
- Crossovers or genetic recombination are absent in haplotypes and haplogroups.
What is the Difference Between Haplogroup and Haplotype?
Haplogroup is a combination of alleles present in different chromosomes that are inherited together. It consists of similar haplotypes sharing a common ancestor. A haplotype, on the other hand, is a set of alleles found in the same chromosome that are inherited together along generations. So, this is the key difference between haplogroup and haplotype.
The below infographic summarizes the difference between haplogroup and haplotype.
Summary – Haplogroup vs Haplotype
Haplogroup is a group of similar haplotypes that share a common ancestor. A haplotype, on the other hand, is a combination of alleles or a set of single nucleotide polymorphisms present on the same chromosome that are passed along generations from a single parent. Therefore, this is the key difference between haplogroup and haplotype. Haplotypes provide an easy way of predicting haplogroups since a haplogroup consists of similar haplotypes.
Reference:
1. “Haplotype.” Genome.gov, Available here.
2. “Haplogroup.” Wikipedia, Wikimedia Foundation, 8 July 2019, Available here.
Image Courtesy:
1. “Molecular lineage” By Wobble – Own work (Public Domain) via Commons Wikimedia
2. “Dna-SNP” By SNP model by David Eccles (gringer) (CC BY 4.0) via Commons Wikimedia