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Lecture

Sex Determination

In course

BIO-373: Genetics and genomics

The theoretical part of this course covers classical genetics and contemporary genomics. Because bioinformatics has become important for genomic research, the course also includes practical applications to genomic analyses using Python, including group pro ...

Description

This lecture covers the different mechanisms of sex determination, including temperature-dependent sex determination in reptiles, sex determination by sexual chromosomes, and anomalies in humans such as Klinefelter and Turner syndromes. It also discusses the role of the Y chromosome, the testis-determining factor, and the sex ratio in humans.

Instructors (2)

Bart Deplancke

Jacques Fellay

Jacques Fellay is a medical scientist with expertise in infectious diseases and human genomics. He obtained his MD from the University of Lausanne in 2002 and his PhD from University of Utrecht. After a clinical training in infectious diseases in Switzerland and a 4-years postdoctoral fellowship at Duke University, he joined the EPFL in April 2011 with an SNF Professorship. On top of his EPFL affiliation, Jacques is also Head of Precision Medicine at the University Hospital (CHUV) in Lausanne, Group Leader at the Swiss Institute of Bioinformatics, and Co-director of the Health2030 Genome Center at Campus Biotech in Geneva.

Official source

Ontological neighbourhood

Biology

Molecular biology: Chromosomes

Related concepts (22)

Y chromosome

The Y chromosome is one of two sex chromosomes in therian mammals and other organisms. The other sex chromosome is the X chromosome. Y is normally the sex-determining chromosome in many species, since it is the presence or absence of Y that determines the male or female sex of offspring produced in sexual reproduction. In mammals, the Y chromosome contains the gene SRY, which triggers male development. The DNA in the human Y chromosome is composed of about 62 million base pairs, making it similar in size to chromosome 19.

Chromosome

A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are the histones. These proteins, aided by chaperone proteins, bind to and condense the DNA molecule to maintain its integrity. These chromosomes display a complex three-dimensional structure, which plays a significant role in transcriptional regulation.

X chromosome

The X chromosome is one of the two sex chromosomes in many organisms, including mammals, and is found in both males and females. It is a part of the XY sex-determination system and XO sex-determination system. The X chromosome was named for its unique properties by early researchers, which resulted in the naming of its counterpart Y chromosome, for the next letter in the alphabet, following its subsequent discovery. It was first noted that the X chromosome was special in 1890 by Hermann Henking in Leipzig.

Turner syndrome

Turner syndrome (TS), also known as 45,X, or 45,X0, is a genetic disorder in which a female has a single X chromosome, compared to the two sex chromosomes (XX or XY) in most people. Signs and symptoms vary among those affected. Often, a short and webbed neck, low-set ears, low hairline at the back of the neck, short stature, and swollen hands and feet are seen at birth. Typically, those affected do not develop menstrual periods or breasts without hormone treatment and are unable to have children without reproductive technology.

XYY syndrome

XYY syndrome, also known as Jacobs syndrome, is an aneuploid genetic condition in which a male has an extra Y chromosome. There are usually few symptoms. These may include being taller than average and an increased risk of learning disabilities. The person is generally otherwise normal, including typical rates of fertility. The condition is generally not inherited but rather occurs as a result of a random event during sperm development. Diagnosis is by a chromosomal analysis, but most of those affected are not diagnosed within their lifetime.

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