Related Experiment Video
Updated: Aug 14, 2026

A Phenotyping Regimen for Genetically Modified Mice Used to Study Genes Implicated in Human Diseases of Aging
Published on: July 14, 2016
Hypogonadotropic hypogonadism; the genetic defect. A hypothesis based on human and animal prototypes
1First Department of Paediatrics, Athens University, Greece.
Abstract:
X-linked hypogonadotropic hypogonadism (HH) in humans may involve the genes responsible for the development and migration of GnRH neurons from the olfactory placode to the hypothalamus. The evidence for this includes the lack of hyperprolactinaemia in cases of X-linked HH, the associated abnormalities in the context of contiguous gene syndromes involving Xp deletions, and pertinent anatomical findings. The genetic defect in human HH appears, therefore, to be different from that found in the hpg mouse model.
Related Concept Videos
In-vitro Mutagenesis
Sex-linked Disorders
Incomplete Dominance
Lethal Alleles
Lucien Cuénot discovered lethal alleles in 1905 while studying the inheritance of coat color in mice. The agouti gene is responsible for the color of the coat in mice. This gene codes for an agouti-signaling protein, which is responsible for melanin distribution in mammals. The wild-type allele gives rise to gray-brown coat color in mice, while the mutant allele gives rise to yellow coat color. In addition to coat color, the agouti gene is associated with the yellow...
X and Y Chromosomes
The germline cells such as egg and sperm cells carry only half the number of chromosomes, i.e., 22 autosomes and one sex chromosome. All eggs have an X chromosome, while sperm cells can carry an X or...
The Y Chromosome Determines Maleness
Evolution
Around 300 million years ago, the two sex chromosomes diverged from two identical autosomal chromosomes. Over time, the Y chromosome has lost most of its genes, shrinking in size. Today,...

