209 Large Offspring Syndrome: Effects of in vitro Production on Embryo Epigenetics and Development

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 114-115
Author(s):  
Rocio Melissa Rivera

Abstract In cattle, the use of assisted reproductive technologies (ART) can result in a congenital overgrowth condition known as large/abnormal offspring syndrome (LOS/AOS). The phenotypic characteristics of LOS include; somatic overgrowth, abdominal wall defects, large organs, breathing difficulties, skeletal defects, hypoglycemia, abnormal placentas, difficulty suckling, and perinatal death. LOS can have detrimental effects on the offspring and dam and also pose managerial and financial challenges to the producer. Research from the Rivera laboratory has demonstrated that LOS is an epigenetic syndrome. As in cattle, ART can promote the development of congenital overgrowth in humans, a condition known as Beckwith Wiedemann Syndrome (BWS). For the past 13 years, the Rivera laboratory has been characterizing LOS and we have shown that LOS and BWS are phenotypically and epigenotypically similar. In our studies, using gestation day ~105 Bos taurus taurus x Bos taurus indicus F1 hybrids, we showed global misregulation of imprinted and non-imprinted transcripts, micro RNAs and global misregulation of DNA methylation. In brief, LOS fetuses displayed variable loss-of-imprinting in kidney, liver, muscle and brain, when compared to controls. Biallelic expression of imprinted genes in LOS was associated with tissue-specific hypomethylation of the normally methylated parental allele. Not only was there loss of allele-specific expression of imprinted genes in LOS, but we also observed differential transcript amounts of these genes between control and overgrown fetuses. In addition, a positive correlation was observed between bodyweight and the number of biallelically expressed imprinted genes in LOS fetuses. From this work, we concluded that LOS is a multi-locus loss-of-imprinting condition. Current work, aims to determine if LOS is identifiable during pregnancy using day 55 fetal ultrasonography and day 55 and 105 maternal blood. In addition, we aim to determine how serum supplementation of culture medium can program preimplantation embryos to develop LOS. Findings will be discussed.

2015 ◽  
Vol 112 (15) ◽  
pp. 4618-4623 ◽  
Author(s):  
Zhiyuan Chen ◽  
Darren E. Hagen ◽  
Christine G. Elsik ◽  
Tieming Ji ◽  
Collin James Morris ◽  
...  

Embryos generated with the use of assisted reproductive technologies (ART) can develop overgrowth syndromes. In ruminants, the condition is referred to as large offspring syndrome (LOS) and exhibits variable phenotypic abnormalities including overgrowth, enlarged tongue, and abdominal wall defects. These characteristics recapitulate those observed in the human loss-of-imprinting (LOI) overgrowth syndrome Beckwith–Wiedemann (BWS). We have recently shown LOI at the KCNQ1 locus in LOS, the most common epimutation in BWS. Although the first case of ART-induced LOS was reported in 1995, studies have not yet determined the extent of LOI in this condition. Here, we determined allele-specific expression of imprinted genes previously identified in human and/or mouse in day ∼105 Bos taurus indicus × Bos taurus taurus F1 hybrid control and LOS fetuses using RNAseq. Our analysis allowed us to determine the monoallelic expression of 20 genes in tissues of control fetuses. LOS fetuses displayed variable LOI compared with controls. Biallelic expression of imprinted genes in LOS was associated with tissue-specific hypomethylation of the normally methylated parental allele. In addition, a positive correlation was observed between body weight and the number of biallelically expressed imprinted genes in LOS fetuses. Furthermore, not only was there loss of allele-specific expression of imprinted genes in LOS, but also differential transcript amounts of these genes between control and overgrown fetuses. In summary, we characterized previously unidentified imprinted genes in bovines and identified misregulation of imprinting at multiple loci in LOS. We concluded that LOS is a multilocus LOI syndrome, as is BWS.


2002 ◽  
Vol 22 (7) ◽  
pp. 2124-2135 ◽  
Author(s):  
Detlev Biniszkiewicz ◽  
Joost Gribnau ◽  
Bernard Ramsahoye ◽  
François Gaudet ◽  
Kevin Eggan ◽  
...  

ABSTRACT Biallelic expression of Igf2 is frequently seen in cancers because Igf2 functions as a survival factor. In many tumors the activation of Igf2 expression has been correlated with de novo methylation of the imprinted region. We have compared the intrinsic susceptibilities of the imprinted region of Igf2 and H19, other imprinted genes, bulk genomic DNA, and repetitive retroviral sequences to Dnmt1 overexpression. At low Dnmt1 methyltransferase levels repetitive retroviral elements were methylated and silenced. The nonmethylated imprinted region of Igf2 and H19 was resistant to methylation at low Dnmt1 levels but became fully methylated when Dnmt1 was overexpressed from a bacterial artificial chromosome transgene. Methylation caused the activation of the silent Igf2 allele in wild-type and Dnmt1 knockout cells, leading to biallelic Igf2 expression. In contrast, the imprinted genes Igf2r, Peg3, Snrpn, and Grf1 were completely resistant to de novo methylation, even when Dnmt1 was overexpressed. Therefore, the intrinsic difference between the imprinted region of Igf2 and H19 and of other imprinted genes to postzygotic de novo methylation may be the molecular basis for the frequently observed de novo methylation and upregulation of Igf2 in neoplastic cells and tumors. Injection of Dnmt1-overexpressing embryonic stem cells in diploid or tetraploid blastocysts resulted in lethality of the embryo, which resembled embryonic lethality caused by Dnmt1 deficiency.


2017 ◽  
Author(s):  
◽  
Zhiyuan Chen

Beckwith-Wiedemann syndrome (BWS) is a congenital overgrowth condition with increased likelihood to develop childhood tumors. Children conceived with the use of assisted reproductive technologies (ART) have an increased frequency to have BWS compared to naturally conceived individuals. In ruminants, the use of ART can induce a similar overgrowth condition that phenotypically recapitulates BWS, which is referred to as large offspring syndrome (LOS). It is believed that these two overgrowth conditions are the result of misregulation of a set of genes that are expressed only from the maternally- or paternally-inherited chromosomes. These genes are known as imprinted genes. In this dissertation, we demonstrate that multiple imprinted genes are misregulated in LOS, as in a subset of BWS. Further, we show that global misregulation of non-imprinted genes in addition to loss-of-imprinting characterizes LOS. Importantly, most of the genes with aberrant expression are not associated with differential DNA methylation, an epigenetic modification that can regulate gene expression. Our results lay the foundation to predict the occurrence of LOS and help understand the molecular mechanisms of these congenital overgrowth conditions.


2019 ◽  
pp. 20-22
Author(s):  
T.I. KUZMINA ◽  
I.V. CHISTYAKOVA

Создание эффективной унифицированной системы дозревания донорских ооцитов обеспечит повышение результативности инновационных клеточных репродуктивных технологий. В исследовании проведен сравнительный мониторинг показателеймейотического созревания ооцитов коров, созревших в различных системах, дополненных структурными компонентами фолликулов (СКФ стенки фолликулов, клетки гранулезы, белки) и фолликулярной жидкостью,а также потенций к развитию из них доимплантационных эмбрионов. Анализу подверглись ооциты, прокультивированные в следующих системах:среда ТС199 с добавлением 10 фетальной бычьей сыворотки (ФБС), 50 мкг/мл эстрадиола, 10 мкг/мл лютеинизирующего гормона (ЛГ), 10 мкг/мл фолликулостимулирующего гормона (ФСГ) среда ТС199 с 10 эстральной сывороткой коров среда ТС199 с 50 жидкости из фолликулов диаметром 9 мм среда ТС199 с добавлением белков фолликулярной жидкости молекулярной массой 65 кДасреда ТС199 с 10 ФБС и 1106 клеток гранулезы среда ТС199 с 10 ФБС и тканью фолликула. В культуральные среды ко всем исследованным группам ооцитов добавляли антибиотики. Использование CКФ обеспечило значительное снижение доли ооцитов с дегенерированным хроматином, что способствовало увеличению уровня доимпланационных эмбрионов на стадии бластоцисты. Так, доля бластоцист, развившихся из ооцитов, созревших в среде со стенками фолликулов,составила43,5. В этой же группе выявлен минимальный уровень дегенерированных зародышей (6,45). Полученные данные предлагается использовать при моделировании систем дозревания ооцитов коров с целью повышения качества яйцеклеток.The creation of an effective unified maturation system of donor oocytes provides an increase in the efficiency of innovative cellular reproductive technologies. The comparative analysis of the meiotic maturation indicators of bovine oocytes, which were matured in different cultural systems modified by follicular structural components (FSC follicular walls, granulosa cells, proteins) and follicular fluid, as well as the potential for preimplantation embryonic development were evaluated in this study. Oocytes matured in following cultural systems: medium TC199 supplemented with 10 fetal bovine serum and 50 g/ml of estradiol, 10 g/ml of luteinizing hormone (LH), 10 g/ml of folliclestimulating hormone (FSH) medium TC199 with 10 estrous cow serum medium TC199 with 50 liquid from follicles with a diameter of 9 mm medium TC199 supplemented with the follicular fluid proteins with molecular weight 65 kDa medium TC199 with 10 fetal bovine serum and 1106 granulosa cells medium TC199 with the addition of 10 fetal bovine serum and follicle tissues were analyzed. Antibiotics were added to cultural media of all experimental groups of oocytes. The usage of FSC ensured the decrease in the proportion of oocytes with degenerated chromatin, which contribute the rise of the level of preimplantation embryos at the blastocyst stage. Thus, the proportion of blastocysts developed from oocytes matured in medium supplemented with follicular walls was 43.5. In the same experimental group, the number of degenerated embryos was 6.45. The obtained data are supposed to be used for modeling the cultural systems of cow oocytes in order to improve the egg quality.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Laura Santini ◽  
Florian Halbritter ◽  
Fabian Titz-Teixeira ◽  
Toru Suzuki ◽  
Maki Asami ◽  
...  

AbstractIn mammalian genomes, differentially methylated regions (DMRs) and histone marks including trimethylation of histone 3 lysine 27 (H3K27me3) at imprinted genes are asymmetrically inherited to control parentally-biased gene expression. However, neither parent-of-origin-specific transcription nor imprints have been comprehensively mapped at the blastocyst stage of preimplantation development. Here, we address this by integrating transcriptomic and epigenomic approaches in mouse preimplantation embryos. We find that seventy-one genes exhibit previously unreported parent-of-origin-specific expression in blastocysts (nBiX: novel blastocyst-imprinted expressed). Uniparental expression of nBiX genes disappears soon after implantation. Micro-whole-genome bisulfite sequencing (µWGBS) of individual uniparental blastocysts detects 859 DMRs. We further find that 16% of nBiX genes are associated with a DMR, whereas most are associated with parentally-biased H3K27me3, suggesting a role for Polycomb-mediated imprinting in blastocysts. nBiX genes are clustered: five clusters contained at least one published imprinted gene, and five clusters exclusively contained nBiX genes. These data suggest that early development undergoes a complex program of stage-specific imprinting involving different tiers of regulation.


2018 ◽  
Author(s):  
Daniel Oreperk ◽  
Sarah A Schoenrock ◽  
Rachel McMullan ◽  
Robin Ervin ◽  
Joseph Farrington ◽  
...  

ABSTRACTParent-of-origin effects (POEs) in mammals typically arise from maternal effects or from imprinting. Mutations in imprinted genes have been associated with psychiatric disorders, as well as with changes in a handful of animal behaviors. Nonetheless, POEs on complex traits such as behavior remain largely uncharacterized. Furthermore, although perinatal environmental exposures, such as nutrient deficiency, are known to modify both behavior and epigenetic effects generally, the architecture of environment-by-POE is almost completely unexplored. To study POE and environment-by-POE, we employ a relatively neglected but maximally powerful POE-detection system: a reciprocal F1 hybrid population. We exposed female NOD/ShiLtJxC57Bl/6J and C57Bl/6JxNOD/ShiLtJ mice, in utero, to one of four different diets, then after weaning recorded their whole-brain gene expression, as well as a set of behaviors that model psychiatric disease. Microarray expression data revealed an imprinting-enriched set of over a dozen genes subject to POE; the POE on the most significantly affected gene, Carmil1 (a.k.a. Lrrc16a), was validated using qPCR in the same and in a new set of mice. Several behaviors, especially locomotor behaviors, also showed POE. Interestingly, Bayesian mediation analysis suggests Carmil1 expression suppresses behavioral POE, and Airn suppresses POE on Carmil1 expression. A significant diet-by-POE was observed on one behavior, one imprinted gene, and over a dozen non-imprinted genes. Beyond our particular results, our study demonstrates a reciprocal F1 hybrid framework for studying POE and environment-by-POE on behavior.


GYNECOLOGY ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 441-444
Author(s):  
Zhanna I. Glinkina ◽  
Elena V. Kulakova ◽  
Elena G. Lebedeva ◽  
Varvara S. Kuzmicheva ◽  
Nataliya P. Makarova

The frequency of structural chromosomal transpositions can range from 1.8 to 8% among patients with reproductive disorders. There are several types of the rarest chromosomal abnormalities: insertion (insertion of a chromosomal region) and inversion (rotation of a chromosome region). This article describes a clinical case of the infertility treatment using assisted reproductive technologies in a woman with a rare chromosomal abnormality: simultaneous insertion and inversion of chromosomes 46, XX, ins (13;4)(q34;p14p15.3), inv(4)(p14q12). The structure and frequency of chromosomal aberrations were determined by high-throughput sequencing in preimplantation embryos. The result of the sequencing analysis showed that unbalanced variants for a known pathology were detected in 9 (56.3%) out of 16 observations, while in 6 (37%) only for a pathology known in the karyotype and in 3 (19%) they were presented simultaneously with the pathology of other chromosomes or with mosaicism. According to the results of the study, in preimplantation embryos, where one of the parents had chromosomal abnormalities, in addition to unbalanced variants, there is aneuploidy of other chromosomes not involved in the known pathology. They are described in 3 (21%) out of 14 observations of all identified pathology. In this regard, patients with aberrations in the karyotype are recommended, whenever possible, to carry out preimplantation genetic testing of structural rearrangements by methods allowed to analyze all chromosomes simultaneously. For example, high-throughput sequencing on the Illumina platform may become an alternative for prenatal diagnostics, which is performed in fertile couples with high risk of having a child with hereditary or congenital disorders. In the case of detection of chromosomal changes in the fetus, patients are faced with a number of ethical issues related to the necessity for medical abortion, which may contradict their religious and moral convictions.


Development ◽  
1998 ◽  
Vol 125 (12) ◽  
pp. 2273-2282 ◽  
Author(s):  
W. Dean ◽  
L. Bowden ◽  
A. Aitchison ◽  
J. Klose ◽  
T. Moore ◽  
...  

In vitro manipulation of preimplantation mammalian embryos can influence differentiation and growth at later stages of development. In the mouse, culture of embryonic stem (ES) cells affects their totipotency and may give rise to fetal abnormalities. To investigate whether this is associated with epigenetic alterations in imprinted genes, we analysed two maternally expressed genes (Igf2r, H19) and two paternally expressed genes (Igf2, U2af1-rs1) in ES cells and in completely ES cell-derived fetuses. Altered allelic methylation patterns were detected in all four genes, and these were consistently associated with allelic changes in gene expression. All the methylation changes that had arisen in the ES cells persisted on in vivo differentiation to fetal stages. Alterations included loss of methylation with biallelic expression of U2af1-rs1, maternal methylation and predominantly maternal expression of Igf2, and biallelic methylation and expression of Igf2r. In many of the ES fetuses, the levels of H19 expression were strongly reduced, and this biallelic repression was associated with biallellic methylation of the H19 upstream region. Surprisingly, biallelic H19 repression was not associated with equal levels of Igf2 expression from both parental chromosomes, but rather with a strong activation of the maternal Igf2 allele. ES fetuses derived from two of the four ES lines appeared developmentally compromised, with polyhydramnios, poor mandible development and interstitial bleeding and, in chimeric fetuses, the degree of chimerism correlated with increased fetal mass. Our study establishes a model for how early embryonic epigenetic alterations in imprinted genes persist to later developmental stages, and are associated with aberrant phenotypes.


2008 ◽  
Vol 20 (1) ◽  
pp. 169 ◽  
Author(s):  
C. E. McHughes ◽  
G. K. Springer ◽  
L. D. Spate ◽  
R. Li ◽  
R. J. Woods ◽  
...  

Identification of transcripts that are present at key development stages of preimplantation embryos is critical for a better understanding of early embryogenesis. To that end, this project had two goals. The first was to characterize the relative abundance of multiple transcripts during several developmental stages, including metaphase II-stage oocytes (MPII), and 2-cell-stage (2-cell), precompact morula (PCM), and in vitro-produced blastocyst-stage (IVTBL) embryos. The second was to characterize differences in the relative abundance of transcripts present in in vivo- (IVVBL), in vitro-, and nuclear transfer-produced (NTBL) blastocysts. It was our hypothesis that the identification of differentially represented transcripts from these stages would reveal not only developmentally important genes, but also genes that might be aberrantly expressed due to embryo production techniques. Individual clusters from a large bovine EST project (http://genome.rnet.missouri.edu/Bovine/), which focused on female reproductive tissues and embryos, were compared using Fisher's exact test weighted by number of transcripts per tissue by gene (SAS PROC FREQ; SAS Institute, Inc., Cary, NC, USA). Of the 3144 transcripts that were present during embryogenesis, 125 were found to be differentially represented (P < 0.01) in at least one pairwise comparison (Table 1). Some transcripts found to increase in representation from the MPII to the 2-cell stage include protein kinases, PRKACA and CKS1, as well as the metabolism-related gene, PTTG1. These same transcripts were also found to decrease in representation from the 2-cell to the PCM stage. RPL15 (translation) and FTH1 (immune function) were both more highly represented in the PCM than in the 2-cell stage. From PCM to IVTBL, we saw an increase in RPS11, another translation-related transcript. When comparing blastocyst-stage embryos from different production techniques, several transcripts involved in energy production (e.g., COX7B and COX8A) were found to be more highly represented in the NTBL than in the IVTBL. COX8A was also more highly represented in the IVVBL than in the IVTBL. By investigating these differentially represented transcripts, we will be able to better understand the developmental implications of embryo manipulation. We may also be able to better develop reproductive technologies that lead to in vitro- and nuclear transfer-derived embryos which more closely follow a normal program of development. Table 1. Differentially represented transcripts between developmental stages


2003 ◽  
Vol 358 (1436) ◽  
pp. 1411-1415 ◽  
Author(s):  
Timothy H. Bestor

There are, in the broadest sense, two mechanisms by which gene expression can be extinguished in vertebrates. The first of these is based on mass action effects of positive and negative regulatory factors and is termed activation and repression; the second is independent of positive regulatory factors but is based on the history of the affected gene and is termed silencing. It can be said, again in the broadest sense, that imprinted genes, genes subject to X inactivation, and transposon promoters are subject to silencing, while the promoters of tissue–specific genes in non–expressing tissues are controlled by activation and repression. The escape of imprinted genes from silencing through unknown mechanisms can cause developmental abnormalities and can predispose to the formation of embryonal tumours. One developmental disorder caused by loss of imprinting of genes on chromosome 11p15.5 is Beckwith–Wiedemann syndrome (BWS). This syndrome has long been known to be inexplicably common in monozygotic twins; the twins are nearly always discordant for BWS, and nearly all twins are female. A loss of imprinting model based on stochastic errors in the nucleocytoplasmic trafficking of the DNA methyltransferase DNMT1, or a paternally expressed function that opposes maintenance methylation of maternally repressed growth–enhancing genes, is proposed to explain the perplexing genetics of BWS in monozygotic twins.


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