Search results for "spermatogenesis"
showing 10 items of 53 documents
Paternal age negatively affects sperm production of the progeny.
2021
International audience; Parental age has profound consequences for offspring’s phenotype. However, whether patrilineal age affects offspring sperm production remains unknown, despite the importance of sperm production for male reproductive success in species facing post-copulatory sexual selection. Using a longitudinal dataset on ejaculate attributes of the houbara bustard, we showed that offspring sired by old fathers had different age-dependent trajectories of sperm production compared to offspring sired by young fathers. Specifically, they produced less sperm (−48%) in their first year of life, and 14% less during their lifetime. Paternal age had the strongest effect, with weak evidence …
What the human sperm methylome tells us.
2017
Aim: To characterize the sperm methylome in semen samples from 19 donors with proven fertility. Materials & methods: Bisulfite-converted sperm DNA was hybridized on the HumanMethylation450 Infinium BeadChip platform. CpG fluorescence intensities were extracted and converted to β-values. Results: The sperm methylome is highly homogeneous and hypomethylated. Genes with hypomethylated promoters are ontologically associated to biological functions related to spermatogenesis and embryogenesis. Sex chromosomes are the most hypomethylated chromosomes, supporting data that indicated their essential role in spermatogenesis. A total of 94 genes are resistant to demethylation, being strong candid…
The DNA methylation profile of human spermatogonia at single-cell- and single-allele-resolution refutes its role in spermatogonial stem cell function…
2019
Human spermatogonial stem cells (hSSCs) have potential in fertility preservation of prepubertal boys or in treatment of male adults suffering from meiotic arrest. Prior to therapeutic application, in vitro propagation of rare hSSCs is mandatory. As the published data points to epigenetic alterations in long-term cell culture of spermatogonia (SPG), an initial characterisation of their DNA methylation state is important. Testicular biopsies from five adult normogonadotropic patients were converted into aggregate-free cell suspensions. FGFR3-positive (FGFR3+) SPG, resembling a very early stem cell state, were labelled with magnetic beads and isolated in addition to unlabelled SPG (FGFR3-). DN…
High Throughput Sequencing Identifies Misregulated Genes in the Drosophila Polypyrimidine Tract-Binding Protein (hephaestus) Mutant Defective in Sper…
2015
The Drosophila polypyrimidine tract-binding protein (dmPTB or hephaestus) plays an important role during spermatogenesis. The heph2 mutation in this gene results in a specific defect in spermatogenesis, causing aberrant spermatid individualization and male sterility. However, the array of molecular defects in the mutant remains uncharacterized. Using an unbiased high throughput sequencing approach, we have identified transcripts that are misregulated in this mutant. Aberrant transcripts show altered expression levels, exon skipping, and alternative 5' ends. We independently verified these findings by reverse-transcription and polymerase chain reaction (RT-PCR) analysis. Our analysis shows m…
Bovine piRNA-like RNAs are associated with both transposable elements and mRNAs.
2017
PIWI proteins and their associated piRNAs have been the focus of intensive research in the past decade; therefore, their participation in the maintenance of genomic integrity during spermatogenesis has been well established. Recent studies have suggested important roles for the PIWI/piRNA system outside of gametogenesis, based on the presence of piRNAs and PIWI proteins in several somatic tissues, cancers, and the early embryo. Here, we investigated the small RNA complement present in bovine gonads, gametes, and embryos through next-generation sequencing. A distinct piRNA population was present in the testis as expected. However, we also found a large population of slightly shorter, 24–27 n…
Endocrine effects of sauna bath
2020
Abstract Sauna bath brings about numerous acute changes in hormone levels, partly akin to other stressful situations, partly specific for sauna. Norepinephrine increases in those accustomed to sauna bath. Sweating increases the production of antidiuretic hormone, and the renin–angiotensin system becomes activated. Of the anterior pituitary hormones, growth hormone (GH) and prolactin (PRL) secretion is increased. Also β-endorphin has been frequently reported to increase, whereas the responses of antidiuretic hormone and cortisol are variable, probably depending on the type of sauna exposure. Sperm production decreases in particular in sauna-naive men, but reduced fertility has not been assoc…
Subcutaneous gonadotropin therapy in male patients with hypogonadotropic hypogonadism
1991
Objective The response to subcutaneous (SC) gonadotropin replacement therapy, using human chorionic gonadotropin (hCG) and human menopausal gonadotropin (hMG) or hCG alone, was evaluated in male hypothalamic hypogonadism. Design Sixteen patients with hypothalamic hypogonadism were treated with gonadotropins for induction of puberty and normalization of spermatogenesis. The results were analyzed retrospectively. Setting The study was carried out in a clinical endocrinology department providing tertiary care and in private practices of endocrinology. Patients Eight patients with idiopathic hypogonadotropic hypogonadism and eight patients with Kallmann's syndrome in prepubertal or early pubert…
Pregnancy in an azoospermic patient with markedly elevated serum follicle-stimulating hormone levels
1995
Objective To assess the possibility of achieving a pregnancy in an azoospermic patient with markedly elevated serum FSH level. Design A case report. Setting In vitro fertilization program at the Instituto Valenciano de Infertilidad. Patient An azoospermic patient with small testes and serum FSH level (38.7 mlU/mL) higher than three times normal. Testicular biopsy revealed Sertoli cell-only syndrome with focal spermatogenesis. Interventions Intracytoplasmic microinjection of testicular tissue-extracted spermatozoa. Main Outcome Measurements: Fertilization rate, cleavage rate, clinical pregnancy. Results Eight of 11 (73%) intact oocytes showed two pronuclei. All of them cleaved normally. Four…
Fertilization after intracytoplasmic sperm injection with cryopreserved testicular spermatozoa.
1996
Objective To assess the possibility of cryopreserving testicular tissue extracted sperm for intracytoplasmic sperm injection (ICSI). Design A report of two cases. Our study was approved by the Ethical Committee at the Instituto Valenciano de Infertilidad. Setting In vitro fertilization program at the Instituto Valenciano de Infertilidad. Patients Two azoospermic patients with severe spermatogenic failure but with focal spermatogenesis on testicular biopsies. In both cases, a first ICSI attempt with fresh testicular biopsy extracted sperm was unsuccessful. Interventions Cryopreservation of testicular spermatozoa in 100-µL "pills." Intracytoplasmic sperm injection with thawed testicular sperm…
Stimulation of Spermatogenesis and Biological Paternity by Intranasal (Low Dose) Gonadotropin-Releasing Hormone (GnRH) in a Male with Kallmann's Synd…
1987
Intranasal (in) GnRH spray caused induction and maintenance of spermatogenesis and biological paternity in a 28-yr-old man with Kallmann's syndrome. Prior treatment had included GnRH analog administration, which failed to induce puberty, and testosterone (T) enanthate weekly. Prior hCG/human menopausal gonadotropin therapy had resulted in high normal serum T levels and near-normal semen quality, but during subsequent hCG therapy, spermatogenesis markedly decreased. The patient had then received 250 mg T enanthate/month for 2 yr and 7 months; it was discontinued 7 weeks before the in GnRH study began. At its start (July 1984) the subject's testis size was 7 mL, and he had azoospermia, low se…