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Printable Handouts
Navigable Slide Index
- Introduction
- Contents (1)
- Multigene family
- Classical example: hemoglobin
- Evolutionary model of multigene families
- Birth-and-death evolution
- Contents (2)
- Variety of odors
- Variety of odors (2)
- Odor-structure relationship
- Similar structures, but distinctive odors
- Similar odors, but distinctive structures
- Contents (3)
- Molecular mechanism of olfaction
- Olfactory receptors
- Sensory receptor genes in humans
- Combinatorial coding
- Odor-receptor relationships
- OR gene SNPs and odor perception (1)
- OR gene SNPs and odor perception (2)
- Contents (4)
- OR genes in the human genome
- Identification of OR genes
- Numbers of OR genes in mammals
- What does it mean “good sense of smell?”
- Do elephants have a good sense of smell?
- Evolutionary change of the no. of OR genes
- Dolphin’s sense
- Number of OR genes in mammals
- Colobines with poor sense of smell (1)
- Colobines with poor sense of smell (2)
- Contents (5)
- Taste
- Taste receptors
- Pheromone
- Vomeronasal organ
- Chemosensory receptor gene families
- Summary
Topics Covered
- Multigene families
- Evolution
- Olfaction
- Taste
- Hemoglobin
- Birth-and-death evolution
- Odor structure
- Olfactory receptors
- Sensory receptors
Talk Citation
Niimura, Y. (2022, February 28). Major gene families in humans and their evolutionary history [Video file]. In The Biomedical & Life Sciences Collection, Henry Stewart Talks. Retrieved April 15, 2025, from https://doi.org/10.69645/DXTB3412.Export Citation (RIS)
Publication History
- Published on February 28, 2022
Financial Disclosures
- Prof. Yoshihito Niimura has not informed HSTalks of any commercial/financial relationship that it is appropriate to disclose.
A selection of talks on Genetics & Epigenetics
Transcript
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0:00
Hello, my name is Yoshihito Niimura
from the University of Miyazaki, Japan.
The title of my talk is Major Gene Families
in Humans and Their Evolutionary History.
0:13
This is the content of my talk.
First, I'd like to talk
about a multigene family.
0:21
A multigene family is a group of genes that
have descended from a common ancestor and,
therefore, have similar functions
and similar DNA sequences.
Historically, a Japanese
geneticist Yoshinari Kuwada,
has mentioned the possibility of chromosome
duplication by observing the chromosomes of maize.
Later, Susumu Ohno published a book entitled
Evolution by Gene Duplication in 1970
and postulated that gene duplication
played a major role in evolution.
A gene duplication generates
two copies of the same gene.
In this situation, it is easier to gain an over function,
because one copy functions as a spare of the original gene.
Therefore, the other gene can alter its
function without losing its original function.
1:16
Hemoglobin provides a classical
example of gene duplication.
It is well known that hemoglobin in red blood cells of
humans is composed of four subunits; two α and two β chains.
There are also γ and δ chains, which are mainly
used in fetuses and newborns, respectively.
In 1961, Ingram proposed that the genes encoding hemoglobin
α, β, γ and δ chains were generated by gene duplication.