BACKGROUND Freeze-drying sperm has been developed as a new preservation method where liquid nitrogen is no longer necessary. An advantage of freeze-drying sperm is that it can be stored at 4 °C and transported at room temperature. Although the successful freeze-drying of sperm has been reported in a number of animals, the possibility of long-term preservation using this method has not yet been ...

Sperm is a highly differentiated cell type whose function is to deliver a haploid genome to the oocyte. The sperm "epigenomes" were traditionally considered to be insignificant - the sperm is transcriptionally inactive, its genome is packaged in sperm-specific protamine toroids instead of nucleosomes, and its DNA methylation profile is erased immediately post-fertilization. Yet, in recent years...

Nucleoprotamines are a normal component of human sperm cells. Antibodies against these protamines develop in 22 to 33 per cent of patients undergoing elective vasectomy. These antibodies, in turn, have been shown to cross-react with medicinal protamines, which are extracted commercially from the testes of salmon and certain other fish. This cross-reactivity against protamines raises the possibi...

Mouse sperm were labeled in vivo with [3H]arginine. The sperm were then followed autoradiographically from the time of label incorporation until after fertilization. The label was completely lost from the sperm head after fertilization, during the oocyte's second meiotic division. That the [3H]arginine was incorporated into a sperm-specific basic protein was demonstrated by fractionating acid e...

Nucleic acids can form large particle complexes with protamine sulfate by electrostatic forces, which results in strong light scattering. Based on this, a nephelometric method is described for sensitive and convenient determination of nucleic acids with protamine sulfate by using a common spectrofluorimeter. Maximum light scattering is produced in the range of pH 2.2-4.4 with the same excitatio...

A standardized cytological preparation of mature mouse sperm has been devised to serve as an in vitro system for probing the intra-ooplasmic molecular events of transformation of the fertilizing sperm. Two parameters of the early phase of transformation in vivo are defined at the resolution of the light microscope: deletion of sperm-unique nuclear proteins, detectable by immunofluorescence, and...

Background: Cysteine has been used as additive in cryopreservation extenders. It contains of thiol group which plays an antioxidant role to eliminate reactive oxygen species (ROS) during freeze -thaw procedure. Excessive ROS production cause DNA damage and subsequently reduce sperm fertility. On the other hand, protamine protein have high levels of cysteine which is critical in packaging and co...

Concentration, motility and morphology are parameters commonly used to determine the fertilization potential of an ejaculate. These parameters give a general view on the quality of sperm but do not provide information about one of the most important components of the reproductive outcome: DNA. Either single or double DNA strand breaks can set the difference between fertile and infertile males....

Global demethylation of DNA which marks the onset of development occurs asynchronously in the mouse; paternal DNA is demethylated at the the zygote stage, whereas maternal DNA is demethylated later in development. The biological function of such asymmetry and its underlying mechanisms are currently unknown. To test the hypothesis that the early demethylation of male DNA may be associated with p...