Protamine 1 to protamine 2 ratio correlates with dynamic aspects of DNA fragmentation in human sperm.

Objective: To investigate the relationship between the protamine 1 to protamine 2 (P1/P2) ratio and the rate of sperm DNA fragmentation in sperm samples from human males with proven fertility and three different cohorts of male patients.

Design: P1/P2 ratio was analyzed using acid-urea polyacrylamide acid-urea gels electrophoresis (PAGE). Sperm DNA fragmentation using sperm chromatin dispersion methodology was analyzed after 0, 4, 8, and 24 hours of incubation at 37°C.

Proteomics in the study of the sperm cell composition, differentiation and function.

A first step in the characterization of cellular functions is the identification of the proteins involved. The spermatozoon is an accessible cell that is particularly suited for analysis and indeed it was one of the first cells from which proteins were identified. An important advance in the identification of the protein composition of the spermatozoa was accomplished in the past using electrophoresis separation methods and protein sequencing with the Edmman procedure.

Identification of proteomic differences in asthenozoospermic sperm samples.

Background: Asthenozoospermia is one of the most common findings present in infertile males, but its aetiology remains unknown in most cases. Present proteomic tools now offer the opportunity to identify proteins which are differentially expressed in asthenozoospermic semen samples and potentially involved in infertility.

Methods: We compared the expression of 101 sperm protein spots in 20 asthenozoospermic samples to that of 10 semen donor controls using two-dimensional proteomic analysis.

Marked correlations in protein expression identified by proteomic analysis of human spermatozoa.

The present work was started to explore whether a correlation could be detected among proteomic expression, protamine content and DNA integrity in human sperm cells. Towards this goal, we extracted the proteins present in the sperm cells from 47 sperm samples from infertile patients and from ten semen donors, analysed each sample by 2-D gel electrophoresis, and quantified the expression of 101 spots identified by MALDI-TOF analysis. Additionally, the protamine content and DNA integrity were also determined.

Proteomics of human spermatozoa, protamine content and assisted reproduction outcome.

It is well known that alterations in the expression of the major sperm nuclear proteins (protamines) are related to infertility in man. In addition, other minor proteins extracted from human spermatozoa are being analysed by 2-dimensional polyacrylamide gel electrophoresis (2-D PAGE) and identified by MALDI-TOF MS analysis. The function of the identified proteins turns out to be energy production, transcription, protein synthesis, transport, folding and turnover, cell cycle, apoptosis and oxidative stress, signal transduction, cytoskeleton, flagella and cell movement, cell recognition, metabolism and unknown function.

Proteomic identification of human sperm proteins.

Conventional 1-DE has in the past provided a wealth of information concerning the major sperm proteins. However, so far there are relatively few reports exploiting the potential of the present proteomic tools to identify and to study additional yet-unidentified important proteins present in human spermatozoa. In the present work, 2-DE of proteins extracted from human normozoospermic spermatozoa led to the resolution of over 1000 spots.