Protamine 2 precursors, protamine 1/protamine 2 ratio, DNA integrity and other sperm parameters in infertile patients
Authors: Torregrosa, Nuria; Domínguez-Fandos, David; Camejo, Maria Isabel; Shirley, Cynthia R.; Meistrich, Marvin L.; Ballescà, José Luis; Oliva, Rafael
Source: Human Reproduction, Volume 21, Number 8, August 2006 , pp. 2084-2089(6)
Publisher: Oxford University Press
Abstract:BACKGROUND: The protamine 1-to-protamine 2 ratio (P1/P2) is altered in the sperm cells of some infertile patients. Also, evidence for increased protamine 2 precursors (pre-P2) in a few patients has been reported. But so far, there have been no studies measuring simultaneously these two variables in a large number of patients. METHODS: We measured the P1/P2 ratio and the presence of pre-P2 using, for the first time, an antibody specific to the precursor pre-P2, together with other sperm parameters in 224 infertile patients. Additionally, the DNA integrity was assessed by terminal transferase dUTP nick-end labelling (TUNEL) in a subset of the samples. RESULTS: Pre-P2 levels show a significant positive correlation with the P1/P2 ratio, with the presence of other proteins and, at low pre-P2 levels, with TUNEL-positive sperm. An inverse correlation with sperm count, normal morphology and motility was detected. CONCLUSIONS: The levels of pre-P2 may provide clues into the pathogenic mechanisms of infertility. The increased proportion of pre-P2 in some patients with increased P1/P2 ratio suggests an involvement of pre-P2 processing. The positive correlation between TUNEL-positive sperm and pre-P2 at low pre-P2/P2 ratios also suggests a link between deficient protamine processing and decreased DNA integrity.
Document Type: Research article
Publication date: 2006-08-01
- Human Reproduction features full-length, peer-reviewed papers reporting original research, clinical case histories, as well as opinions and debates on topical issues. Papers published cover the scientific and medical aspects of reproductive physiology and pathology, endocrinology, andrology, gonad function, gametogenesis, fertilization, embryo development, implantation, pregnancy, genetics, genetic diagnosis, oncology, infectious disease, surgery, contraception, infertility treatment, psychology, ethics and social issues. The highest scientific and editorial standard is maintained throughout the journal along with a rapid rate of publication.