Novel aspects of endometrial function: a biological sensor of embryo quality and driver of pregnancy success

2012 ◽  
Vol 24 (1) ◽  
pp. 68 ◽  
Author(s):  
Olivier Sandra ◽  
Nadéra Mansouri-Attia ◽  
Richard G. Lea

Successful pregnancy depends on complex biological processes that are regulated temporally and spatially throughout gestation. The molecular basis of these processes have been examined in relation to gamete quality, early blastocyst development and placental function, and data have been generated showing perturbations of these developmental stages by environmental insults or embryo biotechnologies. The developmental period falling between the entry of the blastocyst into the uterine cavity to implantation has also been examined in terms of the biological function of the endometrium. Indeed several mechanisms underlying uterine receptivity, controlled by maternal factors, and the maternal recognition of pregnancy, requiring conceptus-produced signals, have been clarified. Nevertheless, recent data based on experimental perturbations have unveiled unexpected biological properties of the endometrium (sensor/driver) that make this tissue a dynamic and reactive entity. Persistent or transient modifications in organisation and functionality of the endometrium can dramatically affect pre-implantation embryo trajectory through epigenetic alterations with lasting consequences on later stages of pregnancy, including placentation, fetal development, pregnancy outcome and post-natal health. Developing diagnostic and prognostic tools based on endometrial factors may enable the assessment of maternal reproductive capacity and/or the developmental potential of the embryo, particularly when assisted reproductive technologies are applied.

GYNECOLOGY ◽  
2018 ◽  
Vol 20 (1) ◽  
pp. 113-116
Author(s):  
L A Bagdasaryan ◽  
I E Korneyeva

The aim of the study is to systematically analyze the data available in the modern literature on the relationship between endometrial thickness and the frequency of pregnancy in the program of assisted reproductive technologies (ART). Materials and methods. The review includes data from foreign and domestic articles found in PubMed on this topic. Results. The article presents data on the relationship between the thickness of the endometrium and the frequency of pregnancy in ART programs. The greatest number of studies is devoted to the evaluation of the relationship between the thickness of the endometrium and the frequency of pregnancy on the day of the ovulation trigger. Data are presented on the existence of a correlation between the thickness of the endometrium measured on the day of the ovulation trigger and the frequency of clinical pregnancy, as well as data on the need to evaluate the structure of the endometrium and the state of subendometric blood flow. The importance of multilayered (three-layered) endometrium as a prognostic marker of success in in vitro fertilization/intracytoplasmic sperm injection programs in the ovum is emphasized. The conclusion. The thickness of the endometrium can not be used as an argument for canceling the cycle or abolishing embryo transfer to the uterine cavity. Further studies in this direction are needed with a study of the morphological and molecular genetic characteristics of the endometrium, which in the future will allow us to evaluate the relationship between the thickness of the endometrium and the probability of pregnancy.


Zygote ◽  
2020 ◽  
Vol 28 (2) ◽  
pp. 154-159
Author(s):  
Juliana I. Candelaria ◽  
Anna C. Denicol

SummaryPreantral follicles are a potential reservoir of oocytes to be used in assisted reproductive technologies. With the increasing interest in developing techniques to grow preantral follicles in vitro, and as the bovine emerges as an appropriate model species to understand human folliculogenesis, the establishment of an accurate classification of developmental stages is needed. Classification of bovine preantral follicles has been mostly based on histological analysis and estimation models, which may not translate well to correctly characterize preantral follicles isolated from the ovary. In this study, we classified bovine preantral follicles by morphology upon isolation, determined diameter and number of granulosa cells by direct counting, and compared our results with previous studies reporting bovine preantral follicle classification. Follicles were isolated via homogenization of ovary tissue and classified into primary, early secondary and secondary stage based on morphology and number of layers of granulosa cells. Diameter was individually measured and Hoechst 33342 was used as a nuclear stain to count granulosa cells. We found that follicles classified by morphology into primary, early secondary, and secondary had different mean diameter and cell number (P < 0.01); cell number and diameter were positively correlated, as were cell density and cell number in each developmental stage (P < 0.01). Results obtained here were mostly in agreement with previous classifications based on histological sections and on isolated follicles, with some discrepancies. The present data add accuracy to classification of bovine preantral follicles that is critical to optimize culture conditions to produce developmentally competent oocytes.


2007 ◽  
Vol 19 (1) ◽  
pp. 166
Author(s):  
X. J. Yin ◽  
H. S. Lee ◽  
E. G. Choi ◽  
X. F. Yu ◽  
B. H. Choi ◽  
...  

Domestic cats are a useful research model to develop assisted reproductive technologies for the conservation of endangered felids. Previously, we produced cloned offspring derived from somatic cell nuclear transfer of ear skin fibroblasts obtained from a deaf, odd-eyed, male Turkish Angora. The aim of this study was to assess the cloning efficiency of the fibroblasts derived from a cloned cat. Fibroblast cell lines were established from 6-mm skin biopsies taken from a deaf, odd-eyed, male Turkish Angora and his clone. The protocol for nuclear transfer was described previously (Yin et al. 2005 Reproduction 129, 245–249). Briefly, cumulus cells were removed from the ova by gently pipetting them into TCM-199 supplemented with 0.1% hyaluronidase. The denuded oocytes were then cultured in TCM-199 supplemented with 0.2 �g mL-1 demecolcine for 1 h and placed into TCM-199 containing 5 �g mL-1 cytochalasin B and 0.2 �g mL-1 demecolcine. The first polar body and protruded chromatin plate were removed with a beveled micropipette. Micromanipulation was used to place a single donor cell nucleus into the perivitelline space of enucleated ova. The ovum-cell couplets were fused and pulse activated. The activated couplets were cultured in 500 �L of CRI medium supplemented with 0.3% BSA for 2 days. The cleaved embryos were cultured in CRII medium supplemented with 10% FBS for 5 days. The cleavage and blastocyst development rates were 38.5% and 3.5% for second generation cloned embryos. A total of 310 second generation cloned embryos were transplanted to 9 surrogates, and 2 pregnancies at 30 days were determined by ultrasonography. One pregnancy was aborted at 40 days of gestation; the second pregnancy continued. These results indicate that the serial cloning of a cat can be generated efficiently up until pregnancy. This work was supported by KOSEF (grant #M10525010001-05N2501-00110).


2007 ◽  
Vol 19 (1) ◽  
pp. 239 ◽  
Author(s):  
R. Krisher ◽  
A. Auer ◽  
K. Clark ◽  
K. Emsweller ◽  
S. Rogers ◽  
...  

The objective of this experiment was to develop in vitro embryo production (IVP) technologies in springbok (Antidorcas marsupialis), a southern African antelope. Springbok, a fairly common species on game farms in parts of South Africa, may be used as a model species for gamete rescue and IVP techniques to be applied to the conservation of other threatened antelope species. Springbok belong to the family bovidae, subfamily antilopinae, tribe antilopini, which comprises about twenty species in genera Gazella, Antilope, Procapra, Antidorcas, Litocranius, and Ammodorcas. In this tribe alone, there are 4 species or subspecies that are critically endangered, 3 that are endangered, and 10 that are considered vulnerable, demonstrating the need for antelope conservation efforts. In addition, our studies contributed to the South African biological resource bank, so that banked springbok semen and embryos might be used in the future for managed genetic contribution to isolated captive or wild populations via assisted reproductive technologies. Oocytes were recovered (3 replicates) from ovaries obtained at supervised culls for management purposes in South Africa, and cultured in defined Gmat or undefined TCM-199 with FCS maturation medium for 28-30 h (Brad et al. 2004 Reprod. Fertil. Dev. 16, 223). Oocytes were fertilized with frozen-thawed springbok epididymal spermatozoa in modified SOF fertilization medium with caffeine (Herrick et al. 2004 Biol. Reprod. 71, 948–958). Eighteen hours after insemination, a randomly selected subset of the zygotes were fixed to determine fertilization success. The remaining zygotes were cultured in G1/G2 media. On Day 7 of culture, embryos were analyzed for development to the morula or blastocyst stage. A total of 259 selected oocytes were collected from 50 females (5.2 selected oocytes/female on average). There was no difference in the percentage of oocytes normally fertilized (2 pronuclei, PN) between oocytes matured in Gmat (n= 43; 12%) and those matured in TCM-199 (n= 42; 10%). There were significantly (P &lt; 0.05) more oocytes penetrated (e2 PN) when matured in TCM (50%) compared to Gmat (23%). There were no differences in embryonic cleavage or morula/blastocyst development (of total oocytes inseminated) between treatments (Gmat,n= 89, 54%, 9.0%; TCM-199, n= 85, 68%, 9.4%, respectively). In both treatments, the average blastocyst grade was 2.125 using the standard bovine grading system (Curtis, Cattle Embryo Transfer Procedure, 1991). In conclusion, in vitro oocyte maturation, fertilization, and embryo culture to the blastocyst stage is possible in springbok. Importantly, blastocysts can be produced in vitro under semi-defined conditions, demonstrating that oocyte maturation without serum does support developmental competence. This is important for the potential international movement of IVP embryos to be used for genetic management in the conservation of antelope species.


2020 ◽  
Vol 32 (2) ◽  
pp. 227
Author(s):  
A. R. Moawad ◽  
H. Benham ◽  
J. P. Barfield

Bison are an important species in North America, both economically and culturally. Although assisted reproductive technologies have been applied to preserve the genetic diversity of bison, development of these technologies remains limited for this species. The objective of the present study was to compare success rates of oocyte maturation, fertilization, and embryo development invitro in bison versus cattle (experiment 1). Cumulus-oocyte complexes obtained from abattoir-derived cattle and bison ovaries were matured, fertilized with frozen semen, and cultured invitro using standard procedures (De La Torre-Sanchez et al. 2006 Reprod. Fertil. Dev. 18, 585-596). At least three replicates were repeated for each experimental group. Oocyte recovery rate was lower in bison than in cattle (4.3; 2797/699 vs. 6.7; 4138/677, oocyte/ovary; P&lt;0.01, t-test). Nuclear maturation (oocytes at MII, 23h post-IVM) and fertilization rates (oocytes with 2 pronuclei 18h post-insemination; p.i.) evaluated by Hoechst stain were lower (P&lt;0.01, chi-square) for bison (65.1%; 56/86 and 32.7%; 18/55, respectively) than for cattle (88.3%; 83/94 and 70.9%; 39/55, respectively). Polyspermy tended to be higher in bison than in cattle (12.7% vs. 3.6%, P=0.08). The percentages of 2-cell embryos tended to be lower in bison than in cattle (13.5% vs. 25.0%, P&gt;0.05) at 24h p.i. but by 30h p.i., this difference increased (33.7% vs. 67.0%, P&lt;0.01, chi-square). Cleavage (Day 3) and blastocyst (Day 7) rates were lower (P&lt;0.01, chi-square) for bison (58.2%; 280/481 and 14.6%; 70/481, respectively) than for cattle (90.8%; 405/446 and 22.9%; 102/446, respectively). Total cell number (74.9±4.8 vs.114.2±5.8), trophectoderm cell numbers (57.9±4.6 vs. 89.2±4.8) and inner cell mass cell numbers (16.9±2.3 vs. 25±1.9) as determined by Hoechst and propidium iodide were all lower (P&lt;0.01, t-test) in bison than in cattle blastocysts. To improve oocyte competence in bison, we evaluated effects of L-carnitine (LC) supplementation during IVM on developmental potential of bison oocytes (experiment 2). Cumulus-oocyte complexes were matured in IVM medium supplemented with 0, 0.15, 0.3, 0.6, or 1.2mgmL−1 LC. No differences were observed in cleavage rates of control (0mgmL−1 LC) and LC-treated groups (values ranged from 60.0 to 66.4%). Interestingly, a dose-dependent increase in blastocyst development was found with the lowest value recorded in control group (10.4%; 14/134) and the highest value in the 1.2mgmL−1 LC supplemented group (22.2%; 23/105; P&lt;0.01, chi-square, n=4). Adding 1.2mgmL−1 LC to the IVM medium improved the percentage of hatching blastocysts compared with the control. In conclusion, bison oocytes exhibited lower invitro maturation, fertilization, and developmental rates compared with cattle oocytes using our system, and bison embryos were delayed in the timing of first cleavage. L-Carnitine supplementation during IVM of bison oocytes improved the preimplantation development and quality of invitro-produced blastocysts.


2019 ◽  
Vol 20 (17) ◽  
pp. 4169
Author(s):  
Marina La Rovere ◽  
Marica Franzago ◽  
Liborio Stuppia

About 1–4% of children are currently generated by Assisted Reproductive Technologies (ART) in developed countries. These babies show only a slightly increased risk of neonatal malformations. However, follow-up studies have suggested a higher susceptibility to multifactorial, adult onset disorders like obesity, diabetes and cardiovascular diseases in ART offspring. It has been suggested that these conditions could be the consequence of epigenetic, alterations, due to artificial manipulations of gametes and embryos potentially able to alter epigenetic stability during zygote reprogramming. In the last years, epigenetic alterations have been invoked as a possible cause of increased risk of neurological disorders, but at present the link between epigenetic modifications and long-term effects in terms of neurological diseases in ART children remains unclear, due to the short follow up limiting retrospective studies. In this review, we summarize the current knowledge about neurological disorders promoted by epigenetics alterations in ART. Based on data currently available, it is possible to conclude that little, if any, evidence of an increased risk of neurological disorders in ART conceived children is provided. Most important, the large majority of reports appears to be limited to epidemiological studies, not providing any experimental evidence about epigenetic modifications responsible for an increased risk.


2018 ◽  
Vol 36 (03/04) ◽  
pp. 211-220 ◽  
Author(s):  
Sneha Mani ◽  
Monica Mainigi

AbstractAssisted reproductive technologies (ARTs) lead to an increased risk for pregnancy complications, congenital abnormalities, and specific imprinting disorders. Epigenetic dysfunction is thought to be one common mechanism which may be affecting these outcomes. The timing of multiple ART interventions overlaps with developmental time periods that are particularly vulnerable to epigenetic change. In vitro embryo culture is known to impact blastocyst development, in vitro fertilization (IVF) success rates, as well as neonatal outcomes. Embryo culture, in contrast to other procedures involved in ART, is obligatory, and has the highest potential for causing alterations in epigenetic reprograming. In this review, we summarize progress that has been made in exploring the effects of embryo culture, culture media, and oxygen tension on epigenetic regulation in the developing embryo. In humans, it is difficult to isolate the role of embryo culture on epigenetic perturbations. Therefore, additional well-controlled animal studies isolating individual exposures are necessary to minimize the epigenetic effects of modifiable factors utilized during ART. Findings from these studies will likely not only improve IVF success rates but also reduce the risk of adverse perinatal outcomes.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yukiko Abe ◽  
Harumi Nakao ◽  
Motoki Goto ◽  
Moe Tamano ◽  
Michinori Koebis ◽  
...  

AbstractGenetic engineering of non-human primates, which are most closely related to humans, has been expected to generate ideal animal models for human genetic diseases. The common marmoset (Callithrix jacchus) is a non-human primate species adequate for the production of genetically modified animals because of their small body size and high reproductive capacity. Autologous embryo transfer (AET) is routinely utilized in assisted reproductive technologies for humans but not for experimental animals. This study has developed a novel method for efficiently producing mutant marmosets using AET and CRISPR/Cas9 systems. The embryos were recovered from oviducts of naturally mated females, injected with Cas9/guide RNA, and transferred into the oviducts of the donors. This AET method can reduce the time for in vitro culture of embryos to less than 30 min. This method uses an embryo donor as the recipient, thus reducing the number of animals and allowing for “Reduction” in the 3R principles of humane experimental technique. Furthermore, this method can utilize nulliparous females as well as parous females. We applied our novel method and generated the 6 marmosets carrying mutations in the fragile X mental retardation 1 (FMR1) gene using only 18 females including 14 nulliparous females.


2020 ◽  
Vol 32 (2) ◽  
pp. 125
Author(s):  
I. Lorenzo ◽  
Z. Li ◽  
M. Torres ◽  
Z. Machaty ◽  
D. Nolte

Assisted reproductive technologies are powerful tools for enhancing production in livestock or treating infertility in humans. Unfortunately, the success rate of the technologies is rather low. A major reason for the poor efficiency is the lack of methods to reliably assess the developmental potential of the embryos before transfer into recipients. Therefore, a noninvasive method to ensure the selection of only the best embryos for transfer would be highly desirable. Biodynamic imaging is a compelling new microscopy that uses intracellular Doppler spectroscopy to perform label-free, noninvasive optical measurements of cellular fitness. The aim of this study was to investigate whether biodynamic imaging can be used to assess the energy status of the embryos, which may be indicative of their viability. Porcine oocytes matured invitro were parthenogenetically activated by an electrical pulse and cultured for 2 days. The parthenotes were then divided into two groups, and approximately half of them were incubated for an additional 2 days in the presence of 20mM sodium azide. Sodium azide is an inhibitor of oxidative phosphorylation and is known to block ATP production. The rest of the embryos were cultured without sodium azide and used as a control to indicate normal ATP levels. At the end of the culture period embryos that reached the 8- to 16-cell stage were evaluated by our biodynamic imaging system to assess their energy status, after which they were lysed and their ATP contents were determined by means of a bioluminescence assay. A total of 68 embryos (32 treated with the inhibitor and 36 control) were evaluated. The ATP content analysis showed that the control embryos had significantly more ATP than those treated with sodium azide as determined by Student's t-test (5.04±1.07 vs. 1.31±0.57; P&lt;0.05). A correlative study was then completed where biodynamic biomarkers were used to classify embryos to estimate the ability of biodynamic imaging to identify embryos with high or low energy status. A set of 13 biomarkers representing each embryo as a feature vector was used to train a classifier. We found that the cross-validated classifier had a sensitivity and specificity of ~80%. In addition, a receiver-operator curve constructed by varying the ATP threshold of the independent bioluminescence assay had an area-under-the-curve of 0.81. These results indicate that biodynamic imaging is able to determine the energy status of the embryos noninvasively and has great potential in the assessment of embryo viability.


Author(s):  
Василий Николаевич Попов ◽  
Роман Борисович Стукалин ◽  
Валерия Александровна Грибанова

В статье проводится анализ представленных на сегодня инвазивных и неинвазивных методов исследования преимплантационных эмбрионов. Показана эффективность преимплантационного генетического тестирования эмбрионов до переноса в полость матки. Также рассмотрены альтернативные менее инвазивные варианты изучения жизнеспособности эмбрионов, которые могли бы являться маркерами успешной имплантации. Проблема бесплодного брака с каждым годом становится все более и более значимой. Для части супружеских пар единственной возможностью рождения ребенка становится лечение методами вспомогательных репродуктивных технологий, эффективность которых остается на сегодняшний день не более 50 %. Особенно важным является поиск новых методик, позволяющих повысить результативность процедур экстракорпорального оплодотворения. В этом направлении крайне интересным является изучение неизвазивных методов оценки имплантационного потенциала эмбрионов. В анализе представлены работы по изучению протеома, метаболома и транскриптома эмбриона. Понимание молекулярного состава культуральных сред, в которых происходило развитие эмбриона до пятых суток культивирования, позволит глубже понять физиологию раннего развития, а также установить неивазивные критерии отбора эмбриона с лучшим имплантационным потенциалом и тем самым повысить эффективность проводимых программ вспомогательных репродуктивных технологий The article analyzes the currently presented invasive and non-invasive methods for studying preimplantation embryos. The efficiency of preimplantation genetic testing of embryos before transfer to the uterine cavity has been shown. Also considered are alternative less invasive options for studying the viability of embryos, which could be markers of successful implantation. The problem of sterile marriage is becoming more and more significant every year. For some married couples, the only possibility of having a child is treatment with methods of assisted reproductive technologies, the effectiveness of which remains at most 50% today. It is especially important to search for new techniques to improve the effectiveness of in vitro fertilization procedures. In this direction, it is extremely interesting to study non-invasive methods for assessing the implantation potential of embryos. The analysis presents works on the study of the proteome, metabolome and transcriptome of the embryo. Understanding the molecular composition of the culture media in which the development of the embryo took place until the fifth day of cultivation will allow a deeper understanding of the physiology of early development and also establish non-invasive criteria for the selection of embryos with the best implantation potential and thereby increase the efficiency of the programs of assisted reproductive technologies


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