Chromatin – DNA fragments by sonication and immunoprecipitated
DNA Fragmentation microbiome and its impact on sperm function a
The semen microbiome and its impact on sperm function and male fertility: A systematic review and meta-analysis
Background: Male factor is attributable in up to 50% of cases of infertility. In-vitro studies demonstrate that bacteria can negatively impact sperm function. The use of next-generation sequencing (NGS) techniques have provided a better understanding of the human microbiome, and dysbiosis has been reported to impact health. Evidence regarding the impact of the semen microbiome on sperm function and fertility remains conflicting.
Materials and methods: A systematic search was conducted in accordance with the Preferred Reporting Items for Reviews and Meta-analysis (PRISMA) statement. The databases MEDLINE, OVID and PubMed were searched to identify English language studies related to the identification of bacteria in the semen of infertile and fertile men, between 1992-2019. 55 observational studies were included, with 51299 subjects. We included studies identifying bacteria using NGS, culture or polymerase chain reaction (PCR).
Results: The semen microbiome (SM) was rich and diverse in both fertile and infertile men. Three NGS studies reported clustering of the seminal microbiome with a predominant species. Lactobacillus and Prevotella were dominant in respective clusters. Lactobacillus was associated with improvements in semen parameters.
Prevotella appeared to exert a negative effect on sperm quality. Bacteriospermia negatively impacted sperm concentration and progressive motility (PM), and DNA fragmentation index (DFI) (MD 3.518,95%CI 0.907 to 6.129, p=0.008). There was an increased prevalence of Ureaplasma urealyticum(UU) in infertile men(OR 2.25, 95% CI 1.47-3.46). UU negatively impacted concentration and morphology.
There was no difference in the prevalence of chlamydia trachomatis (CT) between fertile and infertile men and no significant impact on semen parameters. Enterococcus faecalis (EF) negatively impacted total motility and Mycoplasma hominis (MH) negatively impacted concentration, PM and morphology.
Sperm DNA Fragmentation: A New Guideline for Clinicians
Sperm DNA integrity is crucial for fertilization and development of healthy offspring. The spermatozoon undergoes extensive molecular remodeling of its nucleus during later phases of spermatogenesis, which imparts compaction and protects the genetic content.
Testicular (defective maturation and abortive apoptosis) and post-testicular (oxidative stress) mechanisms are implicated in the etiology of sperm DNA fragmentation (SDF), which affects both natural and assisted reproduction. Several clinical and environmental factors are known to negatively impact sperm DNA integrity.
An increasing number of reports emphasize the direct relationship between sperm DNA damage and male infertility. Currently, several assays are available to assess sperm DNA damage, however, routine assessment of SDF in clinical practice is not recommended by professional organizations.
This article provides an overview of SDF types, origin and comparative analysis of various SDF assays while primarily focusing on the clinical indications of SDF testing. Importantly, we report four clinical cases where SDF testing had played a significant role in improving fertility outcome. In light of these clinical case reports and recent scientific evidence, this review provides expert recommendations on SDF testing and examines the advantages and drawbacks of the clinical utility of SDF testing using Strength-Weaknesses-Opportunities-Threats (SWOT) analysis.
Description: HIV-1 tat recombinant antigen full length 15 kDa
×
Discordance between human sperm quality and telomere length following differential gradient separation/swim-up
Background: Strong evidence has suggested an important role of telomeres in meiosis, fertilization, and embryo development.
Purpose: To determine if sperm telomere length (STL) in sperm purified by differential gradient centrifugation followed by swim-up (selected STL) is correlated with sperm quality and clinical outcomes.
Methods: Relative selected STL was assessed by quantitative polymerase chain reaction (Q-PCR) in 78 consecutive assisted reproductive technology (ART) treatments during 2017. Statistical analyses were performed in the totality of patients, and in normozoospermic and non-normozoospermic patients. These included correlations between selected STL and sperm quality parameters, embryological parameters (multivariable linear regression), and clinical parameters (multivariable logistic regression).
Results: No significant correlations were found between selected STL and sperm quality in the total population. However, selected STL was significantly correlated with total sperm count (r = 0.361; P = 0.039) and sperm DNA fragmentation-post-acrosomal region pattern (r = – 0.464; P = 0.030) in normozoospermic patients. No relation was observed between selected STL and clinical outcomes in any clinical group.
Conclusions: As the correlations observed in normozoospermic patients were not representative of the whole heterogeneous population, differences in the sperm characteristics of the study population may lead to discrepant results when evaluating the association of STL with sperm quality. Since the total population selected STL was not related with sperm quality and with clinical outcomes, results do not support the use of selected STL measurement to evaluate the reproductive potential of the male patient or to predict the success rates of ART treatments.
Keywords: Assisted reproduction; Infertility biomarkers; Male infertility; Sperm telomere length
Description: This gene is a member of the septin family of GTPases. Members of this family are required for cytokinesis. One version of pediatric acute myeloid leukemia is the result of a reciprocal translocation between chromosomes 11 and X, with the breakpoint associated with the genes encoding the mixed-lineage leukemia and septin 2 proteins. This gene encodes four transcript variants encoding three distinct isoforms. An additional transcript variant has been identified, but its biological validity has not been determined.
Description: This gene is a member of the septin family involved in cytokinesis and cell cycle control. This gene is a candidate for the ovarian tumor suppressor gene. Mutations in this gene cause hereditary neuralgic amyotrophy, also known as neuritis with brachial predilection. A chromosomal translocation involving this gene on chromosome 17 and the MLL gene on chromosome 11 results in acute myelomonocytic leukemia. Multiple alternatively spliced transcript variants encoding different isoforms have been described.
Description: This gene is a member of the septin family of nucleotide binding proteins, originally described in yeast as cell division cycle regulatory proteins. Septins are highly conserved in yeast, Drosophila, and mouse, and appear to regulate cytoskeletal organization. Disruption of septin function disturbs cytokinesis and results in large multinucleate or polyploid cells. This gene is highly expressed in brain and heart. Alternatively spliced transcript variants encoding different isoforms have been described for this gene. One of the isoforms (known as ARTS) is distinct; it is localized to the mitochondria, and has a role in apoptosis and cancer.
Description: This gene is a member of the septin gene family of nucleotide binding proteins, originally described in yeast as cell division cycle regulatory proteins. Septins are highly conserved in yeast, Drosophila, and mouse and appear to regulate cytoskeletal organization. Disruption of septin function disturbs cytokinesis and results in large multinucleate or polyploid cells. This gene is mapped to 22q11, the region frequently deleted in DiGeorge and velocardiofacial syndromes. A translocation involving the MLL gene and this gene has also been reported in patients with acute myeloid leukemia. Alternative splicing results in multiple transcript variants. The presence of a non-consensus polyA signal (AACAAT) in this gene also results in read-through transcription into the downstream neighboring gene (GP1BB; platelet glycoprotein Ib), whereby larger, non-coding transcripts are produced.
Description: This gene encodes a protein that is highly similar to the CDC10 protein of Saccharomyces cerevisiae. The protein also shares similarity with Diff 6 of Drosophila and with H5 of mouse. Each of these similar proteins, including the yeast CDC10, contains a GTP-binding motif. The yeast CDC10 protein is a structural component of the 10 nm filament which lies inside the cytoplasmic membrane and is essential for cytokinesis. This human protein functions in gliomagenesis and in the suppression of glioma cell growth, and it is required for the association of centromere-associated protein E with the kinetochore. Alternative splicing results in multiple transcript variants. Several related pseudogenes have been identified on chromosomes 5, 7, 9, 10, 11, 14, 17 and 19.
Description: This gene is a member of the septin family of nucleotide binding proteins, originally described in yeast as cell division cycle regulatory proteins. Septins are highly conserved in yeast, Drosophila, and mouse, and appear to regulate cytoskeletal organization. Disruption of septin function disturbs cytokinesis and results in large multinucleate or polyploid cells. Multiple alternatively spliced transcript variants encoding different isoforms have been found for this gene.
Description: This gene encodes a guanine-nucleotide binding protein and member of the septin family of cytoskeletal GTPases. Septins play important roles in cytokinesis, exocytosis, embryonic development, and membrane dynamics. Multiple transcript variants encoding different isoforms have been found for this gene.
Description: This gene encodes a protein that is highly similar to the CDC10 protein of Saccharomyces cerevisiae. The protein also shares similarity with Diff 6 of Drosophila and with H5 of mouse. Each of these similar proteins, including the yeast CDC10, contains a GTP-binding motif. The yeast CDC10 protein is a structural component of the 10 nm filament which lies inside the cytoplasmic membrane and is essential for cytokinesis. This human protein functions in gliomagenesis and in the suppression of glioma cell growth, and it is required for the association of centromere-associated protein E with the kinetochore. Alternative splicing results in multiple transcript variants. Several related pseudogenes have been identified on chromosomes 5, 7, 9, 10, 11, 14, 17 and 19.
Description: This gene is a member of the septin gene family of nucleotide binding proteins, originally described in yeast as cell division cycle regulatory proteins. Septins are highly conserved in yeast, Drosophila, and mouse and appear to regulate cytoskeletal organization. Disruption of septin function disturbs cytokinesis and results in large multinucleate or polyploid cells. This gene is mapped to 22q11, the region frequently deleted in DiGeorge and velocardiofacial syndromes. A translocation involving the MLL gene and this gene has also been reported in patients with acute myeloid leukemia. Alternative splicing results in multiple transcript variants. The presence of a non-consensus polyA signal (AACAAT) in this gene also results in read-through transcription into the downstream neighboring gene (GP1BB; platelet glycoprotein Ib), whereby larger, non-coding transcripts are produced.
Description: This gene is a member of the septin family of nucleotide binding proteins, originally described in yeast as cell division cycle regulatory proteins. Septins are highly conserved in yeast, Drosophila, and mouse, and appear to regulate cytoskeletal organization. Disruption of septin function disturbs cytokinesis and results in large multinucleate or polyploid cells. Multiple alternatively spliced transcript variants encoding different isoforms have been found for this gene.
Description: This gene is a member of the septin family of GTPases. Members of this family are required for cytokinesis and the maintenance of cellular morphology. This gene encodes a protein that can form homo- and heterooligomeric filaments, and may contribute to the formation of neurofibrillary tangles in Alzheimer's disease. Alternatively spliced transcript variants have been found but the full-length nature of these variants has not been determined. [provided by RefSeq, Dec 2012]
Description: The CLCN5 gene encodes the chloride channel Cl-/H+ exchanger ClC-5. This gene encodes a member of the ClC family of chloride ion channels and ion transporters. The encoded protein is primarily localized to endosomal membranes and may function to facilitate albumin uptake by the renal proximal tubule. Mutations in this gene have been found in Dent disease and renal tubular disorders complicated by nephrolithiasis. Alternatively spliced transcript variants have been found for this gene.
