Detection of P2 precursors in the sperm cells of infertile patients who have reduced protamine P2 levels.
OBJECTIVE
To determine whether the reduction in the protamine P2 content (increased P1/P2 ratio) reported in some infertile patients could result from incomplete processing of protamine P2 precursors.


METHODS
Analysis of samples with a marked reduction in the protamine P2 content using polyacrylamide gel electrophoresis and subsequent detection of protamine P2 precursors through Western blot analysis.


METHODS
University departments and laboratories.


METHODS
One hundred eighty-four men undergoing an evaluation for infertility.


METHODS
Comparative Western blot analysis of nuclear sperm proteins using specific antibodies to protamine P1 and protamine P2.


RESULTS
After selection of the samples with a marked reduction of the protamine P2 content and subsequent analysis by Western blot, a small proportion of putative P2 precursors was detected in most samples, whereas a significant increase was detected in two of them.


CONCLUSIONS
In some infertile men, a reduction in the protamine P2 content relative to protamine P1 (increased P1/P2 ratio) is detected concomitant with an increase in the amount of putative P2 precursors. This could represent the first report of incomplete processing of a nuclear sperm protein in humans.
de Yebra
L
L
Human Genome Research Group, Faculty of Medicine, University of Barcelona, Spain.
Ballescá
J L
JL
Vanrell
J A
JA
Corzett
M
M
Balhorn
R
R
Oliva
R
R
D015153:Blotting, Western; D004247:DNA / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007248:Infertility, Male / Q000378:metabolism* / Q000473:pathology; D008297:Male; D011479:Protamines / Q000032:analysis* / Q000276:immunology; D011498:Protein Precursors / Q000032:analysis*; D013076:Sperm Count; D013094:Spermatozoa / Q000737:chemistry* / Q000473:pathology / Q000502:physiology
D011479:Protamines; D011498:Protein Precursors; C048529:protamine P2; D004247:DNA