scholarly journals Homeostatic regulation of lipid droplet content in mammalian oocytes and embryos

Reproduction ◽  
2021 ◽  
Vol 162 (6) ◽  
pp. R99-R109
Author(s):  
Megumi Ibayashi ◽  
Ryutaro Aizawa ◽  
Junichiro Mitsui ◽  
Satoshi Tsukamoto
Keyword(s):  
Embryonic Development ◽  
Lipid Droplets ◽  
Neutral Lipids ◽  
Mammalian Species ◽  
Early Embryonic Development ◽  
Preimplantation Embryos ◽  
Physiological Importance ◽  
Bovine Oocytes ◽  
Mammalian Embryonic Development ◽  
Development Proceeds

Lipid droplets (LDs) consist of a core of neutral lipids such as triacylglycerols and cholesteryl esters covered by a phospholipid monolayer. Recent studies have shown that LDs not only store neutral lipids but are also associated with various physiological functions. LDs are found in most eukaryotic cells and vary in size and quantity. It has long been known that mammalian oocytes contain LDs. Porcine and bovine oocytes contain substantial amounts of LDs, which cause their cytoplasm to darken, whereas mouse and human oocytes are translucent due to their low LD content. A sufficient amount of LDs in mammalian oocytes has been thought to be associated with oocyte maturation and early embryonic development, but the necessity of LDs has been questioned because embryonic development proceeds normally even when LDs are removed. However, recent studies have revealed that LDs play a crucial role during implantation and that maintaining an appropriate amount of LDs is important for early embryonic development, even in mammalian species with low amounts of LDs in their oocytes. This suggests that a fine-tuned balance of LD content is essential for successful mammalian embryonic development. In this review, we discuss the physiological importance of LDs in mammalian oocytes and preimplantation embryos based on recent findings on LD biology.

Polo-like kinase 4 regulates spindle and actin assembly in meiosis and influence of early embryonic development in bovine oocytes

2016 ◽  
Vol 85 (4) ◽  
pp. 754-761.e1 ◽  
Author(s):  
Shuang Liang ◽  
Ming-Hui Zhao ◽  
Jing Guo ◽  
Jeong-woo Choi ◽  
Nam-Hyung Kim ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Early Embryonic Development ◽  
Actin Assembly ◽  
Bovine Oocytes

scholarly journals Morphological features of lipid droplet transition during porcine oocyte fertilisation and early embryonic development to blastocyst in vivo and in vitro

Zygote ◽  
2002 ◽  
Vol 10 (4) ◽  
pp. 355-366 ◽  
Author(s):  
Kazuhiro Kikuchi ◽  
Hans Ekwall ◽  
Paisan Tienthai ◽  
Yasuhiro Kawai ◽  
Junko Noguchi ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Oocyte Maturation ◽  
Lipid Droplets ◽  
Early Embryonic Development ◽  
Oocyte Activation ◽  
Energy Status ◽  
Thin Sections ◽  
Porcine Oocyte

Lipid content in mammalian oocytes or embryos differs among species, with bovine and porcine oocytes and embryos showing large cytoplasmic droplets. These droplets are considered to play important roles in energy metabolism during oocyte maturation, fertilisation and early embryonic development, and also in the freezing ability of oocytes or embryos; however, their detailed distribution or function is not well understood. In the present study, changes in the distribution and morphology of porcine lipid droplets during in vivo and in vitro fertilisation, in contrast to parthenogenetic oocyte activation, as well as during their development to blastocyst stage, were evaluated by transmission electron microscopy (TEM). The analysis of semi-thin and ultra-thin sections by TEM showed conspicuous, large, electron-dense lipid droplets, sometimes associated with mitochondrial aggregates in the oocytes, irrespective of whether the oocytes had been matured in vivo or in vitro. Immediately after sperm penetration, the electron density of the lipid droplets was lost in both the in vivo and in vitro oocytes, the reduction being most evident in the oocytes developed in vitro. Density was restored in the pronculear oocytes, fully in the in vivo specimens but only partially in the in vitro ones. The number and size of the droplets seemed, however, to have decreased. At 2- to 4-cell and blastocyst stages, the features of the lipid droplets were almost the same as those of pronuclear oocytes, showing a homogeneous or saturated density in the in vivo embryos but a marbled or partially saturated appearance in the in vitro embryos. In vitro matured oocytes undergoing parthenogenesis had lipid droplets that resembled those of fertilised oocytes until the pronuclear stage. Overall, results indicate variations in both the morphology and amount of cytoplasmic lipid droplets during porcine oocyte maturation, fertilisation and early embryo development as well as differences between in vivo and in vitro development, suggesting both different energy status during preimplantation development in pigs and substantial differences between in vitro and in vivo development.

scholarly journals Role of bone morphogenetic protein signaling in bovine early embryonic development and stage specific embryotropic actions of follistatin†

2020 ◽  
Vol 102 (4) ◽  
pp. 795-805 ◽  
Author(s):  
Sandeep K Rajput ◽  
Chunyan Yang ◽  
Mohamed Ashry ◽  
Joseph K Folger ◽  
Jason G Knott ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Bone Morphogenetic Proteins ◽  
Mammalian Species ◽  
Cell Lineage ◽  
Bmp Signaling ◽  
Early Embryonic Development ◽  
Protein Signaling ◽  
Bovine Embryos ◽  
Embryonic Genome

Abstract Characterization of the molecular factors regulating early embryonic development and their functional mechanisms is critical for understanding the causes of early pregnancy loss in monotocous species (cattle, human). We previously characterized a stage specific functional role of follistatin, a TGF-beta superfamily binding protein, in promoting early embryonic development in cattle. The mechanism by which follistatin mediates this embryotropic effect is not precisely known as follistatin actions in cattle embryos are independent of its classically known activin inhibition activity. Apart from activin, follistatin is known to bind and modulate the activity of the bone morphogenetic proteins (BMPs), which signal through SMAD1/5 pathway and regulate several aspects of early embryogenesis in other mammalian species. Present study was designed to characterize the activity and functional requirement of BMP signaling during bovine early embryonic development and to investigate if follistatin involves BMP signaling for its stage specific embryotropic actions. Immunostaining and western blot analysis demonstrated that SMAD1/5 signaling is activated after embryonic genome activation in bovine embryos. However, days 1–3 follistatin treatment reduced the abundance of phosphorylated SMAD1/5 in cultured embryos. Inhibition of active SMAD1/5 signaling (8–16 cell to blastocyst) using pharmacological inhibitors and/or lentiviral-mediated inhibitory SMAD6 overexpression showed that SMAD1/5 signaling is required for blastocyst production, first cell lineage determination as well as mRNA and protein regulation of TE (CDX2) cell markers. SMAD1/5 signaling was also found to be essential for embryotropic actions of follistatin during days 4–7 but not days 1–3 of embryo development suggesting a role for follistatin in regulation of SMAD1/5 signaling in bovine embryos.

scholarly journals Drosophila Lipid Droplets Buffer the H2Av Supply to Protect Early Embryonic Development

2014 ◽  
Vol 24 (13) ◽  
pp. 1485-1491 ◽  
Author(s):  
Zhihuan Li ◽  
Matthew R. Johnson ◽  
Zhonghe Ke ◽  
Lili Chen ◽  
Michael A. Welte
Keyword(s):  
Embryonic Development ◽  
Lipid Droplets ◽  
Early Embryonic Development

NOTCH signaling pathway is required for bovine early embryonic development

2021 ◽  
Author(s):  
Shuang Li ◽  
Yan Shi ◽  
Yanna Dang ◽  
Lei Luo ◽  
Bingjie Hu ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Notch Signaling ◽  
Signaling Pathway ◽  
Notch Pathway ◽  
Notch Signaling Pathway ◽  
Developmental Competence ◽  
Early Embryonic Development ◽  
Preimplantation Embryos ◽  
Early Embryos ◽  
Genes Encoding

Abstract The NOTCH signaling pathway plays an important role in regulating various biological processes, including lineage specification and apoptosis. Multiple components of the NOTCH pathway have been identified in mammalian preimplantation embryos. However, the precise role of the NOTCH pathway in early embryonic development is poorly understood, especially in large animals. Here, we show that the expression of genes encoding key transcripts of the NOTCH pathway is dynamic throughout early embryonic development. We also confirm the presence of active NOTCH1 and RBPJ. By using pharmacological and RNAi tools, we demonstrate that the NOTCH pathway is required for the proper development of bovine early embryos. This functional consequence could be partly attributed to the major transcriptional mediator-RBPJ, whose deficiency also compromised the embryo quality. Indeed, both NOTCH1 and RBPJ knockdown cause a significant increase of histone H3 serine 10 phosphorylation (pH3S10, a mitosis marker) positive blastomeres, suggesting a cell cycle arrest at mitosis. Importantly, RNA-seq analyses reveal that either NOTCH1 or RBPJ depletion triggers a reduction in H1FOO that encodes the oocyte-specific linker histone H1 variant. Interestingly, depleting H1FOO results in detrimental effects on the developmental competence of early embryos, similar with NOTCH1 inhibition. Overall, our results reveal a crucial role for NOTCH pathway in regulating bovine preimplantation development, likely by controlling cell proliferation and maintaining H1FOO expression.

scholarly journals Effect of Bacterial Endotoxins on Superovulated Mouse Embryos In Vivo: Is CSF-1 Involved in Endotoxin-Induced Pregnancy Loss?

2006 ◽  
Vol 2006 ◽  
pp. 1-9 ◽  
Author(s):  
Yogesh Kumar Jaiswal ◽  
Madan Mohan Chaturvedi ◽  
Kaushik Deb
Keyword(s):  
Embryonic Development ◽  
Pregnancy Loss ◽  
Mouse Embryos ◽  
Preimplantation Embryos ◽  
Implantation Failure ◽  
Normal Pattern ◽  
Bacterial Endotoxins ◽  
Mammalian Embryonic Development ◽  
Lps Treatment

Mammalian embryonic development is regulated by several cytokines and growth factors from embryonic or maternal origins. Since CSF-1 plays important role in embryonic development and implantation, we investigated its role in gram-negative bacterial LPS-induced implantation failure. The effect of LPS on normal (nonsuperovulated) and superovulated in vivo-produced embryos was assessed by signs of morphological degeneration. A significantly similar number of morphologically degenerated embryos recovered from both nonsuperovulated and superovulated LPS treated animals on day 2.5 of pregnancy onwards were morphologically and developmentally abnormal as compared to their respective controls (P<.001. Normal CSF-1 expression level and pattern were also altered through the preimplantation period in the mouse embryos and uterine horns after LPS treatment. This deviation from the normal pattern and level of CSF-1 expression in the preimplantation embryos and uterine tissues suggest a role for CSF-1 in LPS-induced implantation failure.

scholarly journals Dynamic analysis of Ca2+level during bovine oocytes maturation and early embryonic development

2011 ◽  
Vol 12 (2) ◽  
pp. 133 ◽  
Author(s):  
Su Li Liang ◽  
Qian Jun Zhao ◽  
Xiang Chen Li ◽  
Ya Ping Jin ◽  
Yi Peng Wang ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Dynamic Analysis ◽  
Early Embryonic Development ◽  
Bovine Oocytes

Effect of centrifugation on early embryonic development and parthenogenetic activation of bovine oocytes matured in vitro

2001 ◽  
Vol 13 (6) ◽  
pp. 383 ◽  
Author(s):  
Jin-Tae Chung ◽  
Bruce R. Downey ◽  
Robert F. Casper ◽  
Ri-Cheng Chian
Keyword(s):  
Embryonic Development ◽  
Calcium Ionophore ◽  
Calcium Ionophore A23187 ◽  
Early Embryonic Development ◽  
Ionophore A23187 ◽  
Vitro Fertilization ◽  
Parthenogenetic Activation ◽  
Treatment Groups ◽  
Bovine Oocytes

This study examined the fertilization, early developmental competence and capacity for parthenogenetic activation of bovine oocytes matured in vitro after centrifugation. Immature oocytes were cultured in tissue culture medium 199 supplemented with 10% fetal bovine serum and 75 mIU mL–1 FSH + LH at 5% CO2 to facilitate maturation. After culture for 24 or 30 h, the metaphase-II stage oocytes were centrifuged at 3000, 5000, 7000 or 10000g for 5 min before in vitro fertilization or parthenogenetic activation. Frozen–thawed bull semen was used for in vitro fertilization. For parthenogenetic activation, the oocytes were exposed to 20 M calcium ionophore A23187 for 5 min at room temperature. Fertilization rates were not different between control and treatment groups (87.7% v. 74.6%, 73.4%, 75.9% and 76.4% respectively). Also, there were no differences in early embryonic development between control and treatment groups (rates of blastocyst formation were 21.1% v. 20.2%, 28.8%, 31.2% and 24.1% respectively). When the oocytes were centrifuged at various speeds alone, the activation rate of oocytes was significantly higher (P<0.05) in the 10 000g treatment group compared with control (10.8% v. 0.0%). There were no differences in the activation rates of oocytes between control and treatment groups at speeds up to 7000g (70.9% v. 71.9%, 78.3% and 77.2% respectively) after centrifugation and stimulation with Ca2+-ionophore. However, the activation rate of oocytes was significantly higher (P<0.05) in the 10 000g treatment group compared with control (70.9% v. 83.1%). In addition, the percentage of activated oocytes with diploid formation was significantly higher in the oocytes after centrifugation at 10 000g and stimulation with calcium ionophore A23187 than in the control (18.4% v. 7.1%). These results indicate that centrifugation of oocytes matured in vitro has no detrimental effect on fertilization and subsequent early embryonic development. They also indicate that the oocytes might be parthenogenetically activated after centrifugation and that high-speed centrifugation may induce activation of some oocytes. The results suggest that the optimal speed for centrifugation of bovine oocytes might be ≤7000g to enhance the visibility of nuclear elements for further micromanipulation.

scholarly journals Function of JARID2 in bovines during early embryonic development

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e4189 ◽  
Author(s):  
Yao Fu ◽  
Jia-Jun Xu ◽  
Xu-Lei Sun ◽  
Hao Jiang ◽  
Dong-Xu Han ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Mrna Expression ◽  
Expression Pattern ◽  
Embryonic Stem ◽  
Early Embryonic Development ◽  
Mouse Development ◽  
Expression Levels ◽  
Relative Expression ◽  
Bovine Oocytes

Histone lysine modifications are important epigenetic modifications in early embryonic development. JARID2, which is a member of the jumonji demethylase protein family, is a regulator of early embryonic development and can regulate mouse development and embryonic stem cell (ESC) differentiation by modifying histone lysines. JARID2 can affect early embryonic development by regulating the methylation level of H3K27me3, which is closely related to normal early embryonic development. To investigate the expression pattern of JARID2 and the effect of JARID2-induced H3K27 methylation in bovine oocytes and early embryonic stages, JARID2 mRNA expression and localization were detected in bovine oocytes and early embryos via qRT-PCR and immunofluorescence in the present study. The results showed that JARID2 is highly expressed in the germinal vesicle (GV), MII, 2-cell, 4-cell, 8-cell, 16-cell and blastocyst stages, but the relative expression level of JARID2 in bovine GV oocytes is significantly lower than that at other oocyte/embryonic stages (p < 0.05), and JARID2 is expressed primarily in the nucleus. We next detected the mRNA expression levels of embryonic development-related genes (OCT4, SOX2 and c-myc) after JARID2 knockdown through JARID2-2830-siRNA microinjection to investigate the molecularpathwayunderlying the regulation of H3K27me3 by JARID2 during early embryonic development. The results showed that the relative expression levels of these genes in 2-cell embryos weresignificantly higher than those in the blastocyst stage, and expression levels were significantly increased after JARID2 knockdown. In summary, the present study identified the expression pattern of JARID2 in bovine oocytes and at each early embryonic stage, and the results suggest that JARID2 plays a key role in early embryonic development by regulating the expression of OCT4, SOX2 and c-myc via modification of H3K27me3 expression. This work provides new data for improvements in the efficiency ofin vitroembryo culture as well as a theoretical basis for further studying the regulatory mechanisms involved in early embryonic development.

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