SPERM DNA
FRAGMENTATION
Dr.SATYAWAN
ROLL NO. 1516
ASPIRE
SPERM DNA
FRAGMENTATION
*The genetic integrity of the spermatozoon is essential for
normal embryo development.
*A high level of DNA fragmentation in sperm cells may
represent a cause of male infertility.
Elevated levels of DNA fragmentation above the critical
threshold will significantly compromise the possibility of a
successful pregnancy.
*High sperm DNA fragmentation does not appear to affect fertilization
or the first or second embryo cleavage stages.
*High sperm DNA fragmentation can affect embryo cleavage once the
paternal genome is switched on, and subsequent blastocyst
development.
*DNA fragmentation levels are closely correlated with IUI, IVF and
ICSI miscarriage and pregnancy rates.
*DNA fragmentation is significantly higher in subfertile men.
*Men with poor semen parameters are more likely to have high DNA
fragmentation.
*High sperm DNA fragmentation is also found in men with normal
semen parameters.
ADVANTAGES OF THE SPERM DNA
FRAGMENTATION TEST
 This test provides a reliable analysis of sperm DNA integrity
that may help to identify men who are at risk of failing to
initiate a healthy ongoing pregnancy.
 Information about sperm DNA integrity may help in the
clinical diagnosis, management and treatment of male
infertility and may be of prognostic value in assessing outcome
of assisted conception treatment.
SPERM DNA PECULIARITY
 During spermiogenesis spermatids repackage their DNA with protamines, a small
residue of histone-bound DNA is retained (15%).
 Are proteins with a high content of positively charged amino acids (48% arginine)
 Form a highly condensed complex with the sperm DNA
 Incorporate cysteins.
 Cysteins allow the formation of disulphide bonds between the protamines.
 Therefore strongly stabilize the nucleoprotamine complex.
 In mature sperm the DNA is
• 85% protamine bound
• 15 % remains histone bound
ETIOLOGY OF SPERM DNA
DAMAGE
 The etiology of sperm DNA damage is multifactorial:-
 In the testis during the process of spermatogenesis:
 Apoptosis: screening mechanisms, that mark individual apoptotic sperms which
causes phagocytosis of these cell, failed.
 – during remodeling of sperm chromatin the DNA is unwound through the
induction of strand breaks, sperms with unrepaired strand breaks semen.
ETIOLOGY OF SPERM DNA
DAMAGE
 post-testicular:
 – during sperm transport through the seminiferous tubules and
the epididymis
 – Varicocoele , Genital tract infections (leukocytes), Immature
sperms (cytoplasmic droplet), radio- and/or chemotherapy,
Lifestyle factors (obesity, cell phones, nicotine), environmental
toxicants, Laboratory factors
 • Majority of DNA damage is associated with ROS.
ROS
 Small levels are essential for normal sperm functions
(capacitation, acrosome reaction, sperm-oocyte fusion.
 Balance between ROS production and scavenging system is
important
 In 25% of infertile men high ROS levels have been detected
in their semen.
DNA FRAGMENTATION TESTS
 Sperm chromatin structure assay (SCSA)-measures the intensity of acridin orange (AO)
fluorescence using flow cytometry
 TdT-mediated-dUTPnick end labeling(TUNEL) assay-detects both single-and double-
stranded DNA breaks microscopically or using flow cytometry
 Single cell gel electrophoresis (COMET) assay-involves embedding spermatozoa in agarose
on a glass slide, applying electrophoresis, and evaluating DNA migration in comet tails
 Sperm chromatin dispersion test (SCD)-sperm with fragmented DNA –no halo of dispersed
DNA loops that is observed in sperm with non-fragmented DNA following acid denaturation and
removal of nuclear proteins.
 Halo sperm kit
RESULT & TREATMENT
Condition
Normozoospermia
Oligozoospermia
Asthenozoospermia
Teratozoospermia
Description
Production of sperm in normal
numbers and motility.
Low Sperm count. Density
<15mill/ml.
Reduced sperm motility <39%.
Reduced morphology. N.Mor
>4
Treatment
IUI or Convention IVF.
ICSI Backup (IVF & ICSI
depending on severity on day of
clinical treatment).
ICSI if severe.
ICSI if severe.
Cryptozoospermia
Necrozoospermia
Globozoospermia
Aspermia
Azoospermia
Apparent Azoospermic sample
but where sperm found during
only after centrifugation
Sample with only immotile
sperm
Sperm morphological head
defect (Round head).
Retrograde ejaculation.
No spermatozoa in the
ejaculate obstructive. Sperm are
created but cannot mix with the
rest of the ejaculatory fluid due
to physical obstruction
(CBAVD). Non- obstructive:
where there is problem with
spermatogenesis.
ICSI in cases it may be best
practice to freeze a sample prior
to treatment to ensure
availability of sperm on day of
treatment.
Treatment with their own
sperm is not presently an
option.
ICSI.
ICSI If sperm is found.
If sperm found then ICSI.
ACHIEVEMENT OF PREGNANCY
 84% of men with DFI of <15% achieved a
pregnancy during the first 3 months
 10% of men with a DFI<30% achieved a
pregnancy during months 4-12
 20% of men with a DFI > 30% never
achieved a pregnancy
ACHIEVEMENT OF PREGNANCY
 in the general population:
1-4% of men have a DFI > 30%.
 Infertility patients
 a DFI > 30% have
• IUI patients: 7%
• IVF patients: 16%
• ICSI patients: 33%
TREATMENT
 Some causes of DNA fragmentation cannot be treated, but if the damage is caused
by free radicals, then a change in lifestyle and a diet designed to protect against
oxidative stress may help reduce the levels of DNA fragmentation in some of these
cases. Treatment of infection with antibiotics would also be expected to reduce DNA
fragmentation. There is some evidence to show that varicocoele repair may improve
sperm DNA integrity. Initiatives to reduce the levels of fragmentation can be assessed
by undertaking a second test three months after the first. Initial reports suggest that
DNA damage occurs at the post-testicular level, so that testicular sperm may have a
healthier DNA integrity than ejaculated sperm. Furthermore, studies show that ICSI
may be a more effective treatment than IVF for sperm with a high DNA fragmentation.
Thank
you

Dna fragmentation

  • 1.
  • 2.
    SPERM DNA FRAGMENTATION *The geneticintegrity of the spermatozoon is essential for normal embryo development. *A high level of DNA fragmentation in sperm cells may represent a cause of male infertility. Elevated levels of DNA fragmentation above the critical threshold will significantly compromise the possibility of a successful pregnancy.
  • 3.
    *High sperm DNAfragmentation does not appear to affect fertilization or the first or second embryo cleavage stages. *High sperm DNA fragmentation can affect embryo cleavage once the paternal genome is switched on, and subsequent blastocyst development. *DNA fragmentation levels are closely correlated with IUI, IVF and ICSI miscarriage and pregnancy rates. *DNA fragmentation is significantly higher in subfertile men. *Men with poor semen parameters are more likely to have high DNA fragmentation. *High sperm DNA fragmentation is also found in men with normal semen parameters.
  • 4.
    ADVANTAGES OF THESPERM DNA FRAGMENTATION TEST  This test provides a reliable analysis of sperm DNA integrity that may help to identify men who are at risk of failing to initiate a healthy ongoing pregnancy.  Information about sperm DNA integrity may help in the clinical diagnosis, management and treatment of male infertility and may be of prognostic value in assessing outcome of assisted conception treatment.
  • 5.
    SPERM DNA PECULIARITY During spermiogenesis spermatids repackage their DNA with protamines, a small residue of histone-bound DNA is retained (15%).  Are proteins with a high content of positively charged amino acids (48% arginine)  Form a highly condensed complex with the sperm DNA  Incorporate cysteins.  Cysteins allow the formation of disulphide bonds between the protamines.  Therefore strongly stabilize the nucleoprotamine complex.  In mature sperm the DNA is • 85% protamine bound • 15 % remains histone bound
  • 6.
    ETIOLOGY OF SPERMDNA DAMAGE  The etiology of sperm DNA damage is multifactorial:-  In the testis during the process of spermatogenesis:  Apoptosis: screening mechanisms, that mark individual apoptotic sperms which causes phagocytosis of these cell, failed.  – during remodeling of sperm chromatin the DNA is unwound through the induction of strand breaks, sperms with unrepaired strand breaks semen.
  • 7.
    ETIOLOGY OF SPERMDNA DAMAGE  post-testicular:  – during sperm transport through the seminiferous tubules and the epididymis  – Varicocoele , Genital tract infections (leukocytes), Immature sperms (cytoplasmic droplet), radio- and/or chemotherapy, Lifestyle factors (obesity, cell phones, nicotine), environmental toxicants, Laboratory factors  • Majority of DNA damage is associated with ROS.
  • 8.
    ROS  Small levelsare essential for normal sperm functions (capacitation, acrosome reaction, sperm-oocyte fusion.  Balance between ROS production and scavenging system is important  In 25% of infertile men high ROS levels have been detected in their semen.
  • 9.
    DNA FRAGMENTATION TESTS Sperm chromatin structure assay (SCSA)-measures the intensity of acridin orange (AO) fluorescence using flow cytometry  TdT-mediated-dUTPnick end labeling(TUNEL) assay-detects both single-and double- stranded DNA breaks microscopically or using flow cytometry  Single cell gel electrophoresis (COMET) assay-involves embedding spermatozoa in agarose on a glass slide, applying electrophoresis, and evaluating DNA migration in comet tails  Sperm chromatin dispersion test (SCD)-sperm with fragmented DNA –no halo of dispersed DNA loops that is observed in sperm with non-fragmented DNA following acid denaturation and removal of nuclear proteins.  Halo sperm kit
  • 10.
    RESULT & TREATMENT Condition Normozoospermia Oligozoospermia Asthenozoospermia Teratozoospermia Description Productionof sperm in normal numbers and motility. Low Sperm count. Density <15mill/ml. Reduced sperm motility <39%. Reduced morphology. N.Mor >4 Treatment IUI or Convention IVF. ICSI Backup (IVF & ICSI depending on severity on day of clinical treatment). ICSI if severe. ICSI if severe.
  • 11.
    Cryptozoospermia Necrozoospermia Globozoospermia Aspermia Azoospermia Apparent Azoospermic sample butwhere sperm found during only after centrifugation Sample with only immotile sperm Sperm morphological head defect (Round head). Retrograde ejaculation. No spermatozoa in the ejaculate obstructive. Sperm are created but cannot mix with the rest of the ejaculatory fluid due to physical obstruction (CBAVD). Non- obstructive: where there is problem with spermatogenesis. ICSI in cases it may be best practice to freeze a sample prior to treatment to ensure availability of sperm on day of treatment. Treatment with their own sperm is not presently an option. ICSI. ICSI If sperm is found. If sperm found then ICSI.
  • 12.
    ACHIEVEMENT OF PREGNANCY 84% of men with DFI of <15% achieved a pregnancy during the first 3 months  10% of men with a DFI<30% achieved a pregnancy during months 4-12  20% of men with a DFI > 30% never achieved a pregnancy
  • 13.
    ACHIEVEMENT OF PREGNANCY in the general population: 1-4% of men have a DFI > 30%.  Infertility patients  a DFI > 30% have • IUI patients: 7% • IVF patients: 16% • ICSI patients: 33%
  • 14.
    TREATMENT  Some causesof DNA fragmentation cannot be treated, but if the damage is caused by free radicals, then a change in lifestyle and a diet designed to protect against oxidative stress may help reduce the levels of DNA fragmentation in some of these cases. Treatment of infection with antibiotics would also be expected to reduce DNA fragmentation. There is some evidence to show that varicocoele repair may improve sperm DNA integrity. Initiatives to reduce the levels of fragmentation can be assessed by undertaking a second test three months after the first. Initial reports suggest that DNA damage occurs at the post-testicular level, so that testicular sperm may have a healthier DNA integrity than ejaculated sperm. Furthermore, studies show that ICSI may be a more effective treatment than IVF for sperm with a high DNA fragmentation.
  • 15.