The purpose of this study was to determine the negative effects (cryodamage) on human spermatozoa after freeze-thawing and to determine whether freeze-thawing of spermatozoa with a programmed slow freezer is better than freezing with liquid nitrogen vapour (rapid freezing) with regard to alterations in sperm chromatin and morphology in semen from fertile (donor) and subfertile, IVF/ICSI, patien...

BACKGROUND Sperm cells extracted from testes (TESE) have poor chromatin quality and motility. Various substances are used in the laboratory to increase sperm motility and improve the ART outcomes; however, there are few research which considered improving both sperm motility and chromatin quality. OBJECTIVE The aim of this investigation was to evaluate the improvement of the testicular sperm ...

BACKGROUND The condensed state of the human sperm's chromatin is essential for the compact structure of the spermatozoon head, which is important for the fertilization process. The enzymes DNA topoisomerases (topo I and topo II) are responsible for the topological structure of the chromatin in somatic cells. The activities and the characterization of topoisomerases in mature human sperm cells h...

Hallmarks of the terminal stages of apoptosis are genomic DNA fragmentation and chromatin condensation. Here, we have studied the mechanism of condensation both in vitro and in vivo. We found that DNA fragmentation per se of isolated nuclei from non-apoptotic cells induced chromatin condensation that closely resembles the morphology seen in apoptotic cells, independent of ATP utilization, at ph...

Background: Alcohol abuse is considered as one of the problems associated with poor semen production and sperm quality. Both acute and chronic alcohol consumption may affect spermatozoal chromatin disorders through apoptosis. Therefore, for the first time, this experimental study was performed to evaluate the effect of ethanol consumption on sperm parameters and chromatin integrity of spermatoz...

We find that the remodeling of the condensed Xenopus laevis sperm nucleus into the paternal pronucleus in egg extracts is associated with phosphorylation of the core histones H2A, H2A.X and H4, and uptake of a linker histone B4 and a HMG 2 protein. Histone B4 is required for the assembly of chromatosome structures in the pronucleus. However neither B4 nor core histone phosphorylation are requir...

Apoptosis is the predominant form of cell death observed in a variety of physiological and pathological conditions such as cancer involution, insect metamorphosis, the development of the immune and nervous systems, and embryogenesis. The typical nuclear changes taking place in apoptotic cells include extensive condensation of chromatin and internucleosomal DNA fragmentation into units of 200 ba...

The accurate assessment of avian sperm abnormalities is hampered by a lack of descriptive data and by the confusing terminology currently in use. Critical appraisal of semen samples from the distal ductus deferens of the emu revealed that two closely related yet separate (distinct) defects previously collectively referred to as "bent sperm" or "crooked-necked sperm" could be identified by light...

Protamines are abundant basic proteins involved in the condensation of sperm chromatin. In the mouse, protamine genes are transcribed postmeiotically in round spermatids. We have cloned and sequenced the mouse protamine 1 gene. Ten lines of transgenic mice harboring marked protamine 1 sequences were generated by microinjection of fertilized eggs. Transcription of the transgene is restricted to ...