Superovulation Influences Methylation Reprogramming and Delays Onset of DNA Replication in Both Pronuclei of Mouse Zygotes

2018 ◽  
Vol 156 (2) ◽  
pp. 95-105 ◽  
Author(s):  
Elif Diken ◽  
Matthias Linke ◽  
Jan Baumgart ◽  
Leonid Eshkind ◽  
Dennis Strand ◽  
...  

Although an essential component of assisted reproductive technologies, ovarian stimulation, or superovulation, may interfere with the epigenetic reprogramming machinery during early embryogenesis and gametogenesis. To investigate the possible impact of superovulation particularly on the methylation reprogramming process directly after fertilization, we performed immunofluorescence staining of pronuclear (PN) stage embryos with antibodies against 5mC and 5hmC. PN stage embryos obtained by superovulation displayed an increased incidence of abnormal methylation and hydroxymethylation patterns in both maternal and paternal pronuclear DNA. Subsequent single-cell RT-qPCR analyses of the Tet1, Tet2, and Tet3 genes revealed no significant expression differences between PN stage embryos from spontaneously and superovulated matings that could be causative for the abnormal methylation and hydroxymethylation patterns. To analyze the possible contribution of TET-independent replication-associated demethylation mechanisms, we then determined the 5mC and 5hmC levels of PN stage mouse embryos using immunofluorescence analyses after inhibition of DNA replication with aphidicolin. Inhibition of DNA replication had no effect on abnormal methylation and hydroxymethylation patterns that still persisted in the superovulated group. Interestingly, the onset of DNA replication, which was also analyzed in these experiments, was remarkably delayed in the superovulated group. Our findings imply an impact of superovulation on both replication-dependent and -independent or yet unknown demethylation mechanisms in PN stage mouse embryos. In addition, they reveal for the first time a negative effect of superovulation on the initiation of DNA replication in PN stage mouse embryos.

Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 475
Author(s):  
Maria Santa Rocca ◽  
Ludovica Dusi ◽  
Andrea Di Nisio ◽  
Erminia Alviggi ◽  
Benedetta Iussig ◽  
...  

Telomeres are considered to be an internal biological clock, and their progressive shortening has been associated with the risk of age-related diseases and reproductive alterations. Over recent years, an increasing number of studies have focused on the association between telomere length and fertility, identifying sperm telomere length (STL) as a novel biomarker of male fertility. Although typically considered to be repeated DNA sequences, telomeres have recently been shown to also include a long non-coding RNA (lncRNA) known as TERRA (telomeric repeat-containing RNAs). Interestingly, males with idiopathic infertility show reduced testicular TERRA expression, suggesting a link between TERRA and male fertility. The aim of this study was to investigate the role of seminal TERRA expression in embryo quality. To this end, STL and TERRA expression were quantified by Real Time qPCR in the semen of 35 men who underwent assisted reproductive technologies (ART) and 30 fertile men. We found that TERRA expression in semen and STL was reduced in patients that underwent ART (both p < 0.001). Interestingly, TERRA and STL expressions were positively correlated (p = 0.010), and TERRA expression was positively associated with embryo quality (p < 0.001). These preliminary findings suggest a role for TERRA in the maintenance of sperm telomere integrity during gametogenesis, and for the first time, TERRA expression was found as a predictive factor for embryo quality in the setting of assisted reproduction.


GYNECOLOGY ◽  
2020 ◽  
Vol 22 (6) ◽  
pp. 21-26
Author(s):  
Natalia V. Aleksandrova

The article systematizes information on the diagnostic capabilities of modern clinical and laboratory markers of ovarian reserve. The diagnostic capabilities of anti-Mllerian hormone (AMH) as a marker of ovarian reserve are discussed, which make it possible to adjust the dose of hormonal drugs and predict the response of the ovary to stimulation in programs of assisted reproductive technologies. This paper discusses for the first time the role of AMH in assessing the quality of oocytes and subsequent embryos. Despite insufficient literature data, further study of AMH, as well as full-scale research in this direction, seems to be extremely promising.


2018 ◽  
Vol 30 (10) ◽  
pp. 1352 ◽  
Author(s):  
Aimee J. Silla ◽  
Michael McFadden ◽  
Phillip G. Byrne

Fundamental knowledge of the optimal hormone concentrations required to stimulate amplexus and spawning in breeding pairs of amphibians is currently lacking, hindering our understanding of the proximate mechanisms underpinning mating behaviour. The present study investigated the effects of: (1) the dose of a gonadotropin-releasing hormone analogue (GnRH-a) administered; (2) male–female hormone administration interval; and (3) topical application of GnRH-a, on spawning success in the northern corroboree frog. Administration of GnRH-a at doses of 0.5, 1.0 and 2.0 μg g−1 were highly successful, with a significantly greater proportion of hormone-treated pairs ovipositing (89–100%) compared with the 0 μg g−1 treatment (22%). Of the hormone-treated pairs, those receiving 0.5 μg g−1 GnRH-a exhibited the highest fertilisation success (61%). Administration of GnRH-a to males and females simultaneously (0 h) was more effective than injecting males either 48 or 24 h before the injection of females. Overall, administration of GnRH-a was highly successful at inducing spawning in northern corroboree frogs. For the first time, we also effectively induced spawning following the topical application of GnRH-a to the ventral pelvic region. Topical application of GnRH-a eliminates the need for specialised training in amphibian injection, and will allow assisted reproductive technologies to be adopted by a greater number of captive facilities globally.


2020 ◽  
Vol 69 (5) ◽  
pp. 99-104
Author(s):  
Inga V. Gorelova ◽  
Ksenia A. Prikhodko ◽  
Maxim V. Rulev ◽  
Irina E. Zazerskaya

The presence of antibodies to thyroid peroxidase and thyroglobulin of the thyroid gland in women with infertility is more common than in the population. Some studies describe the negative effect of autoantibodies on reproductive function and the results of assisted reproductive technology (ART) programs even in the absence of impaired thyroid function. This article presents a review of literature data on the possible mechanisms of this negative influence. To date, there are no data on a significant decrease in the quality of oocytes, embryos and pregnancy rates in ART cycles in such patients. The negative effect of autoantibodies on the frequency of live births can be realized through such complications of pregnancy as miscarriage and premature birth. Currently, the possibilities for preventing these complications are poorly understood. According to recent meta-analyses, the use of levothyroxine in euthyroid patients with autoantibodies who are treated for infertility using ART methods does not result in a decrease in the frequency of miscarriage and premature birth.


Author(s):  
Manuel Belli ◽  
Paolo Rinaudo ◽  
Maria Grazia Palmerini ◽  
Elena Ruggeri ◽  
Sevastiani Antonouli ◽  
...  

Assisted Reproductive Technologies routinely utilize different culture media and oxygen (O2) concentrations to culture human embryos. Overall, embryos cultured under physiological O2 tension (5%) have improved development compared to embryos cultured under atmospheric O2 conditions (20%). The mechanisms responsible for this remain unclear. This study aimed to evaluate the effect of physiologic (5%) or atmospheric O2 (20%) tension on the microscopic ultrastructure of pre-implantation mouse embryos using Transmission Electron Microscopy (TEM). Embryos flushed out of the uterus after natural mating were used as the control. For use as the control, 2-cells, 4-cells, morulae, and blastocysts were flushed out of the uterus after natural fertilization. In vitro fertilization (IVF) was performed using potassium simplex optimized medium (KSOM) under different O2 tensions (5% and 20%) until the blastocyst stage. After collection, embryos were subjected to the standard preparative for light microscopy (LM) and TEM. We found that culture in vitro under 5% and 20% O2 results in an increase of vacuolated shaped mitochondria, cytoplasmic vacuolization and presence of multi-vesicular bodies at every embryonic stage. In addition, blastocysts generated by IVF under 5% and 20% O2 showed a lower content of heterochromatin, an interruption of the trophectodermal and inner cell mass cell membranes, an increased density of residual bodies, and high levels of glycogen granules in the cytoplasm. In conclusion, this study suggests that in vitro culture, particularly under atmospheric O2 tension, causes stage-specific changes in preimplantation embryo ultrastructure. In addition, atmospheric (20%) O2 is associated with increased alterations in embryonic ultrastructure; these changes may explain the reduced embryonic development of embryos cultured with 20% O2.


Reproduction ◽  
2005 ◽  
Vol 130 (5) ◽  
pp. 599-601 ◽  
Author(s):  
Joshua Sommovilla ◽  
Warren B Bilker ◽  
Ted Abel ◽  
Richard M Schultz

The oldest assisted reproductive technologies (ART)-conceived child is only 27 years old. Thus, the effects of ART on longevity are unknown, and it will be many years before this can be assessed in humans. We recently reported that culturing preimplantation mouse embryos under suboptimal conditions results in differences in how the offspring perform in behavioral assays that reflect anxiety (elevated zero maze) and spatial memory (Morris hidden water maze; Ecker et al. 2004). Here we monitored the mice generated in our previous study and found no difference in their longevity.


2017 ◽  
pp. 66-67
Author(s):  
T.V. Leshcheva ◽  
◽  
E.L. Romanenko ◽  

The objective: depression of frequency of notincubation at primapara is more senior than 40 years on the basis of studying the clinical-ehografical, endocrinological, biochemical and microbiological changes, and also improvement of algorithm of diagnostic and treatment-and-prophylactic actions. Patients and methods. Сlinical-functional and laboratory examination is conducted 80 primapara is more senior than 40 years which were divided into two groups and two subgroups. Control group made 20 primapara aged from 20 till 30 years, without obstetric and somatic pathology and the burdened genesial anamnesis. Results. The studies show that women who give birth for the first time at the age of over 40 years history revealed high incidence of infertility (76.3%), the main causes of which are female factor (41.1%), clothing (34.8% ) and combined (24.1%). The total incidence of miscarriage in women was 15.0%; after making pregnancy – 10.0%, and after assisted reproductive technologies – 20.0%. As for the timing of premature pregnancy, the more likely it is 8 weeks of pregnancy (50.0%) and less – 10 weeks (33.3%) and 12 weeks (16.7%). Conclusion. Use of an advanced treatment-and-prophylactic technique at primapara is more senior than 40 years allows not only to reduce significantly the frequency of a spontaneous abortion in І a trimester, but also to improve obstetric and perinatal results of delivery. Key words: notincubation, diagnostics, prophylaxis, age is more senior than 40 years.


2016 ◽  
Vol 28 (7) ◽  
pp. 995 ◽  
Author(s):  
Caitlin E. McDonough ◽  
Michelle W. Martin ◽  
Carrie K. Vance ◽  
Judith A. Cole ◽  
Andrew J. Kouba

Amphibians are experiencing a global extinction crisis and captive assurance colonies, along with reintroduction programs, are necessary to prevent further losses. Assisted reproductive technologies (ART), such as hormone-stimulated gamete collection and in vitro fertlisation (IVF), are conservation methods that can be used to increase reproductive output for breeding and reintroduction programs when animals fail to breed naturally. In order to maximise the production of offspring using ART, it is important to establish the physiological limitations on the frequency that hormone therapy can be used to collect gametes for IVF or assisted breeding. The present study examined the effects of the frequency of hormone-induced spermiation on sperm quantity and quality in Fowler’s toad (Bufo fowleri) by comparing four levels of hormone injection frequencies: twice a week, once a week, every other week, and every 3 weeks. Sperm release was induced with an intraperitoneal injection of 300 IU human chorionic gonadotropin (hCG). Spermatozoa were collected at three time points after injection (5, 7 and 9 h) and sperm concentration, motility and quality of forward progressive movement were measured. A significant decrease in sperm concentration (P < 0.01) was observed with the most frequent treatment (twice a week hormone injections). However, there was no negative effect of the treatments on sperm motility (P = 0.06) or forward movement (P = 0.06). We also observed a significant decrease in the concentration (P < 0.01), motility (P = 0.02) and quality of forward progressive movement (P = 0.01) of spermatozoa at the 9 h collection compared with earlier collection times. These results have clear implications for amphibian captive breeding programs, where more frequent hormone-induced spermiation could have a negative effect on male performance. We recommend that hormone injections be spaced a minimum of 2 weeks apart to optimise the health of the animals, assisted breeding, IVF or collection of gametes for genome resource banking.


2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Audrey J. Kindsfather ◽  
Megan A. Czekalski ◽  
Catherine A. Pressimone ◽  
Margaret P. Erisman ◽  
Mellissa R. W. Mann

Abstract Background Over the last several decades, the average age of first-time mothers has risen steadily. With increasing maternal age comes a decrease in fertility, which in turn has led to an increase in the use of assisted reproductive technologies by these women. Assisted reproductive technologies (ARTs), including superovulation and embryo culture, have been shown separately to alter imprinted DNA methylation maintenance in blastocysts. However, there has been little investigation on the effects of advanced maternal age, with or without ARTs, on genomic imprinting. We hypothesized that ARTs and advanced maternal age, separately and together, alter imprinted methylation in mouse preimplantation embryos. For this study, we examined imprinted methylation at three genes, Snrpn, Kcnq1ot1, and H19, which in humans are linked to ART-associated methylation errors that lead to imprinting disorders. Results Our data showed that imprinted methylation acquisition in oocytes was unaffected by increasing maternal age. Furthermore, imprinted methylation was normally acquired when advanced maternal age was combined with superovulation. Analysis of blastocyst-stage embryos revealed that imprinted methylation maintenance was also not affected by increasing maternal age. In a comparison of ARTs, we observed that the frequency of blastocysts with imprinted methylation loss was similar between the superovulation only and the embryo culture only groups, while the combination of superovulation and embryo culture resulted in a higher frequency of mouse blastocysts with maternal imprinted methylation perturbations than superovulation alone. Finally, the combination of increasing maternal age with ARTs had no additional effect on the frequency of imprinted methylation errors. Conclusion Collectively, increasing maternal age with or without superovulation had no effect of imprinted methylation acquisition at Snrpn, Kcnq1ot1, and H19 in oocytes. Furthermore, during preimplantation development, while ARTs generated perturbations in imprinted methylation maintenance in blastocysts, advanced maternal age did not increase the burden of imprinted methylation errors at Snrpn, Kcnq1ot1, and H19 when combined with ARTs. These results provide cautious optimism that advanced maternal age is not a contributing factor to imprinted methylation errors in embryos produced in the clinic. Furthermore, our data on the effects of ARTs strengthen the need to advance clinical methods to reduce imprinted methylation errors in in vitro-produced embryos.


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