Related Experiment Video
Updated: May 8, 2026

A Cell-Free Assay Using Xenopus laevis Embryo Extracts to Study Mechanisms of Nuclear Size Regulation
Published on: August 8, 2016
Nuclear size as estrogen-responsive chromatin quality parameter of mouse spermatozoa
Giovanna Cacciola1, Teresa Chioccarelli, Lucia Altucci
1Dipartimento di Medicina Sperimentale, Sez. Bottazzi, Seconda Università di Napoli, Via Costantinopoli 16, 80138 Napoli, Italy.
Abstract:
Recently, we have investigated the endocannabinoid involvement in chromatin remodeling events occurring in male spermatids. Indeed, we have demonstrated that genetic inactivation of the cannabinoid receptor type 1 (Cnr1) negatively influences chromatin remodeling mechanisms, by reducing histone displacement and indices of sperm chromatin quality (chromatin condensation and DNA integrity). Conversely, Cnr1 knock-out (Cnr1(-/-)) male mice, treated with estrogens, replaced histones and rescued chromatin condensation as well as DNA integrity. In the present study, by exploiting Cnr1(+/+), Cnr(+/-) and Cnr1(-/-) epididymal sperm samples, we show that histone retention directly correlates with low values of sperm chromatin quality indices determining sperm nuclear size elongation. Moreover, we demonstrate that estrogens, by promoting histone displacement and chromatin condensation rescue, are able to efficiently reduce the greater nuclear length observed in Cnr1(-/-) sperm. As a consequence of our results, we suggest that nucleus length may be used as a morphological parameter useful to screen out spermatozoa with low chromatin quality.
Related Concept Videos
Chromatin Packaging
Chromatin Packaging
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
Chromatin Position Affects Gene Expression
Topologically Associated Domains (TADs)
The 3-dimensional positioning of chromatin in the nucleus influences the timing and level of...
Regulation of Nuclear Protein Sorting
Euchromatin
Euchromatin is the less dense region of the chromatin and stains lighter. Euchromatin contains histone H3 extensively...

