Influence of extended incubation time on Human sperm chromatin condensation, sperm DNA strand breaks and their effect on fertilisation rate

Andrologia ◽  
2018 ◽  
Vol 50 (4) ◽  
pp. e12960 ◽  
Author(s):  
I. Ahmed ◽  
S. Abdelateef ◽  
M. Laqqan ◽  
H. Amor ◽  
M. A. Abdel-Lah ◽  
...  
Keyword(s):  
Incubation Time ◽  
Chromatin Condensation ◽  
Human Sperm ◽  
Dna Strand Breaks ◽  
Sperm Chromatin ◽  
Strand Breaks ◽  
Fertilisation Rate ◽  
Sperm Dna ◽  
Dna Strand ◽  
Sperm Chromatin Condensation

scholarly journals Pre-apoptotic Alterations in Hepatocytes of TNF α-treated Galactosamine-sensitized Mice

1998 ◽  
Vol 46 (10) ◽  
pp. 1175-1183 ◽  
Author(s):  
Sabine Angermüller ◽  
Gerald Künstle ◽  
Gisa Tiegs
Keyword(s):  
Enzyme Activity ◽  
Plasma Membrane ◽  
Cytochrome Oxidase ◽  
Oxidase Activity ◽  
Chromatin Condensation ◽  
Dna Strand Breaks ◽  
Strand Breaks ◽  
High Enzyme ◽  
Dna Strand ◽  
High Enzyme Activity

Tumor necrosis factor (TNF) induces apoptotic death of hepatocytes in the galactosamine (GalN)-sensitized mouse liver after 5 hr. In our study, the most remarkable sign of the early stage of apoptosis was the focal rupture of the outer mitochondrial membrane. Parts of the inner membrane extended through the gap of the outer membrane, whereas the rest of the inner membrane still formed the cristae. This feature appeared in hepatocytes before chromatin condensation. With the diaminobenzidine technique for localization of cytochrome oxidase activity, the reaction product was detectable by light and electron microscopy. Ten percent of the hepatocytes were apoptotic, with condensed chromatin and high enzyme activity, 37% were pre-apoptotic, without chromatin condensation but high enzyme activity, and 53% had neither condensed chromatin nor a remarkable reaction product of cytochrome oxidase activity. Fas (APO-1, CD95) molecules on the plasma membrane of hepatocytes increased and were represented immunohistochemically in cells without chromatin condensation. DNA strand breaks were also detectable before chromatin aggregation. The results of this study indicate that mitochondria play a pivotal role in pre-apoptotic hepatocytes, together with an increase of the Fas molecule on the plasma membrane and with the occurrence of DNA strand breaks in the nucleus.

scholarly journals 265 SPERM DNA FRAGMENTATION AND PREGNANCY OUTCOME

2005 ◽  
Vol 17 (2) ◽  
pp. 282
Author(s):  
D. Evenson
Keyword(s):  
Flow Cytometry ◽  
Pregnancy Outcome ◽  
Dna Fragmentation ◽  
Dna Strand Breaks ◽  
Sperm Dna Fragmentation ◽  
Strand Breaks ◽  
Threshold Levels ◽  
Fragmented Dna ◽  
Sperm Dna ◽  
Dna Strand

Sperm DNA integrity is obviously important for normal embryo development and pregnancy outcome. Over the past 25 years, various methods have been developed to measure sperm DNA strand breaks in situ. The Sperm Chromatin Structure Assay (SCSA) treats sperm with low pH to denature DNA at the sites of DNA strand breaks, followed by acridine orange (AO) staining of green for native DNA and red for denatured DNA, as measured by flow cytometry (FCM), as well as % sperm with high DNA stainability (HDS: immature sperm with intact DNA related to decreased fertilization rates). FCM-sorted sperm from each SCSA-defined population (normal, moderate, and high DNA fragmentation and HDS sperm) show that the moderate DNA fragmentation index (DFI) population has the same image analysis characteristics as normal sperm without significant comets. Thus, an ICSI technician is not likely to differentiate between a normal and a moderate DFI sperm. The TUNEL assay uses an enzyme to add a fluorochrome-labeled base to a 3′-OH broken DNA strand. Both light microscopy and flow cytometry are used for measuring the % and extent of DNA fragmentation but cannot measure the level of HDS. For the COMET assay, sperm are suspended in an electrophoretic gel, placed on a glass microscope slide, digested with proteases and RNAse, subjected to an electric field, and then stained with a DNA dye. The % of comet positive sperm is scored, but the extent of fragmentation is difficult to define and the % HDS cannot be determined. Small pieces of fragmented DNA migrate in the gel forming a “comet.” All three methods have been used for both research and clinical diagnosis and as prognosis for livestock (bulls, boars, rams, stallions) and humans. Light microscope techniques suffer from a lack of statistical soundness needed for clinical decisions as well as present a potential bias in selection of sperm for measurements. Due to the thousands of sperm randomly selected for flow cytometry measurements, the data are statistically robust. Data from all three kinds of measurements in over a hundred manuscripts clearly show that sperm DNA fragmentation has a negative impact on embryo growth and pregnancy. Infertile animals may have nearly all of the sperm with fragmented DNA. Fertility ratings in bulls and boars are clearly related to the percent and extent of DNA fragmentation. Threshold levels for fertile/sub fertile/infertile differ for different species. Likewise different methods/laboratories have suggested various threshold levels to characterize a man with a highly fertile to low/very poor potential. The range of sperm with fragmented DNA is from ∼2% to 100%. The SCSA method has defined a 27–30% DFI as the point in which a man is placed into a statistical category of taking a longer time to achieve in vivo pregnancy, more intrauterine insemination and routine IVF cycles, or no pregnancy. Current data suggest that ICSI may help overcome the diminished pregnancy prognosis with high DFI over the other ART or natural methods.

DNA strand breaks in human sperm cells, A comparison between men with normal and oligozoospermic sperm samples

1999 ◽  
Vol 78 (4) ◽  
pp. 336-339 ◽  
Author(s):  
Erik Høst ◽  
Svend Lindenberg ◽  
Jarl A. Kahn ◽  
Flemming Christensen
Keyword(s):  
Human Sperm ◽  
Dna Strand Breaks ◽  
Sperm Cells ◽  
Strand Breaks ◽  
Dna Strand

scholarly journals The Drosophila chromosomal protein Mst77F is processed to generate an essential component of mature sperm chromatin

Open Biology ◽  
2016 ◽  
Vol 6 (11) ◽  
pp. 160207 ◽  
Author(s):  
Shuhei Kimura ◽  
Benjamin Loppin
Keyword(s):  
Chromatin Condensation ◽  
Rapid Evolution ◽  
Mature Sperm ◽  
Sperm Chromatin ◽  
Chromosomal Protein ◽  
Sperm Dna ◽  
Cross Links ◽  
Sperm Chromatin Condensation

In most animals, the bulk of sperm DNA is packaged with sperm nuclear basic proteins (SNBPs), a diverse group of highly basic chromosomal proteins notably comprising mammalian protamines. The replacement of histones with SNBPs during spermiogenesis allows sperm DNA to reach an extreme level of compaction, but little is known about how SNBPs actually function in vivo . Mst77F is a Drosophila SNBP with unique DNA condensation properties in vitro , but its role during spermiogenesis remains unclear. Here, we show that Mst77F is required for the compaction of sperm DNA and the production of mature sperm, through its cooperation with protamine-like proteins Mst35Ba/b. We demonstrate that Mst77F is incorporated in spermatid chromatin as a precursor protein, which is subsequently processed through the proteolysis of its N-terminus. The cleavage of Mst77F is very similar to the processing of protamine P2 during human spermiogenesis and notably leaves the cysteine residues in the mature protein intact, suggesting that they participate in the formation of disulfide cross-links. Despite the rapid evolution of SNBPs, sperm chromatin condensation thus involves remarkably convergent mechanisms in distantly related animals.

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