Related Experiment Video
Updated: Jul 28, 2026

Fish Sperm Assessment Using Software and Cooling Devices
Published on: July 28, 2018
Polyploidy in large-headed sperm: FISH study of three cases
F Devillard1, C Metzler-Guillemain, R Pelletier
1Laboratoire de Cytogénétique, Biologie de la Reproduction et CECOS, Centre Hospitalo-Universitaire de Grenoble, 38043 Grenoble cedex 09, France.
Background:
Macrocephalic or large headed sperm with multiflagella is a rare abnormality often associated with infertility. Sperm chromosomal abnormalities could be associated with this specific morphological abnormality.
Methods:
The cytogenetic content of large-headed sperm was assessed by dual and three-colour fluorescence in-situ hybridization in three patients carrying this specific morphological abnormality.
Results:
In all patients nearly all sperm contained at least one copy of each sex chromosome, and in more than half of them at least two copies of either chromosome 1 or 18 were identified. In some sperm a tetraploidy was found.
Conclusions:
These observations suggested that both meiotic I and II divisions were affected by incomplete partition of homologous chromosomes during meiosis I and of sister chromatids during meiosis II associated with a failure of nuclear cleavage. Furthermore, they provide evidence for a clear relationship between a specific morphological abnormality of the sperm and their abnormal cytogenetic content. The treatment of infertility using ICSI would probably be unsuccessful and have a high genetic risk in these cases.
Related Concept Videos
Spermatogenesis
Formation of Species
Nondisjunction
Lampbrush Chromosomes
LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops resemble the...
Polytene Chromosomes
Nondisjunction

