Cellular cyclic adenosine-3’ 5’-monophosphate (cAMP) modulator is known as meiotic inhibitor and can delays spontaneous maturation in IVM experiment. Among many cAMP modulators, the role of Pituitary adenylate cyclase activating polypeptide (PACAP) on IVM isn’t known. The purpose of this study is to improve the maturation of oocytes derived from follicles ≤ 3 mm in diameter through PACAP as meiotic inhibitor during pre-in vitro maturation (pre-IVM). First, we checked PACAP and its receptors in cumulus cells and, to establish the optimal phase and concentration of PACAP for pre-IVM, we conducted chromatin configuration assessments. As a result, the rate of GV (Germinal Vesicle) according to duration of pre-IVM was significantly decreased 12 h and 18 h after IVM (87.1 and 84.1%, respectively) compared to 0 h (99.4%). When COC was cultured for 18 h, the GV rate in the 1 μM of PACAP treatment group (82.1%) was significantly higher than any other PACAP treatment groups (60.5, 64.1, 74.4 and 69.9 %, respectively). So, we divided into four groups as follows; MF (the conventional IVM group, obtained from follicle from 3 to 6 mm in diameter), SF (the conventional IVM group, obtained from follicle ≤ 3mm in diameter), Pre-SF(-)PACAP (IVM group including 18 h pre-IVM without 1 μM of PACAP, obtained from follicle ≤ 3mm in diameter) and Pre-SF(+)PACAP (IVM group including 18 h pre-IVM with 1 μM of PACAP, obtained from follicle ≤ 3mm in diameter). To examine the effect of PACAP during pre-IVM, we investigated analysis of nuclear maturation, intracellular glutathione (GSH) and reactive oxygen species (ROS) levels. In cumulus cells, PACAP receptors, ADCYAP1R1 and VIPR1 were detected but were not detected in oocytes. After IVM, the Pre-SF(+)PACAP had the highest Metaphase II rate (91.7%) among all groups (P<0.05). The GSH levels in the MF and Pre-SF(+)PACAP were significantly higher than in the other groups (P<0.05) and ROS levels was no significant difference among all groups. In conclusion, these results indicated that even though the oocytes were derived from SF, pre-IVM application of PACAP improved meiotic and cytoplasmic maturation by regulating intracellular oxidative stress.
Alpha lipoic acid (ALA) is a biological membranes compound. As the antioxidant, it decreases the oxidized forms of other antioxidant substances such as vitamin C, vitamin E, and glutathione (GSH). To examine the effect of ALA on the in vitro maturation (IVM) of porcine oocytes, we investigated intracellular GSH and reactive oxygen species (ROS) levels, and subsequent embryonic development after parthenogenetic activation (PA). Intracellular GSH levels in oocytes treated with 50uM ALA increased significantly (P < 0.05) and exhibited a significant (P < 0.05) decrease in intracellular ROS levels compared with the control group. Oocytes matured with 50 uM of ALA during IVM displayed significantly higher cleavage rates (67.8% vs. 83.4%, respectively), and higher blastocyst formation rates and total cell number of blastocysts after PA (31.6%, 58.49 vs. 46.8%, 68.58, respectively) than the control group. In conclusion, these results suggest that treatment with ALA during IVM improves the cytoplasmic maturation of porcine oocytes by increasing the intracellular GSH levels, thereby decreasing the intracellular ROS levels and subsequent embryonic developmental potential of PA.
Ferulic Acid (FA) is a metabolite of phenylalanine and tyrosine, a phenolic compound commonly found in fruits and vegetables. Several studies have shown that FA has various functions such as antioxidant effect, prevention of cell damage from irradiation, protection from cell damage caused by oxygen deficiency, anti-inflammatory action, anti-aging action, liver protective effect and anti-cancer action. In this study, we investigated the maturation rate, intracellular glutathione (GSH) and reactive oxygen species (ROS) of porcine oocytes by adding FA to the in vitro maturation (IVM) medium and examined subsequent embryonic developmental competence at 5% oxygen through parthenogenesis. There is no significant difference between the control group (0μM) and treatment groups (5μM, 10μM, 20μM) on maturation rates. Intracellular GSH levels in oocyte treated with 5μM of FA significantly increased (P < 0.05), and 20μM of FA revealed significant decrease (P < 0.05) in intracellular ROS levels compared with the control group. Oocytes treated with FA exhibited significantly higher cleavage rates (79.01% vs 89.19%, 92.20%, 90.89%, respectively) than the control group. Oocytes treated with 10μM showed significantly higher blastocyst formation rates (28.3% vs 40.3%, respectively) after PA than the control group. Total cell numbers in blastocyst of 10μM FA displayed significantly higher (39.4 vs 51.9, respectively) than the control group. In conclusion, these results suggested that treatment with FA during IVM improved the developmental potential of porcine embryos by increasing intracellular GSH synthesis and reducing ROS levels. Also, there was an improvement of cleavage rate, blastocyst formation and total cell numbers in blastocysts. It might be associated with Keap1-Nrf2 pathway as an antioxidant regulate pathway that plays a crucial role in determining the sensitivity of cells to oxidative damages by regulating the basal and inducible expression of enzymes which is related to detoxification and anti-oxidative effects, stress response enzymes and/or proteins and ABC transporters.
The objective of this study was to determine the effect of fructose that was supplemented to a chemically defined in Vitro maturation (IVM) medium on oocyte maturation and embryonic development after parthenogenesis in pigs. The base medium for in Vitro maturation (IVM) was porcine zygote medium (PZM) that was supplemented with 0.05% (w/v) polyvinyl alcohol (PVA) or 10% (v/v) porcine follicular fluid (pFF). In the first experiment, when immature pig oocytes were matured in a chemically defined medium that was supplemented with 5.5 mM glucose or with 1.5, 3.0 and 5.5 mM fructose, 3.0 mM fructose resulted in a higher nuclear maturation (91.5%) than 1.5 and 5.5 mM fructose (81.9 and 81.9%, respectively) but showed a similar result with 5.5 mM glucose (94.2%). However, there was no significant differences among groups in the embryo cleavage (89.4-92.4%), blastocyst formation (37.5-41.1%), and mean cell number of blastocyst (30.8-34.2 cells). Fructose at the concentration of 3.0 mM (1.08 pixels/oocyte) resulted in a higher intra-oocyte glutathione (GSH) content than 1.5 and 5.5 mM fructose (1.00 and 0.87 pixels/oocytes, respectively) while the cumulus cell expansion was not influenced. In the second experiment, effect of individual and combined supplementation of a chemically defined maturation medium with 5.5 mM glucose or 3.0 mM fructose was examined. No significant effect was found in the nuclear maturation (86.3-92.6%). Embryo cleavage was significantly increased by the combined supplementation with glucose and fructose (95.2%) compared to that with 3.0 mM fructose only (85.7%) while blastocyst formation (37.3-42.8%) and embryonic cell number (33.3-34.1 cells) were not altered. Effect of supplementation of pFF-containing medium with glucose and fructose + glucose was examined in the third experiment. No significant effect by the supplementation with glucose and fructose or glucose alone was observed in the nuclear maturation of oocytes (90.7-94.1%) and blastocyst formation (51.0-56.5%). Our results demonstrate that 3.0 mM fructose was comparable to 5.5 mM glucose in supporting in Vitro oocyte maturation and embryonic development after parthenogenesis and could be used as an alternative energy source to glucose for in Vitro maturation of pig oocytes.
Severe combined immune deficiency (SCID) pig is very important research model for biomedical research, such as the development of humanized tissues and organs for transplantation and long-term evaluation of transplanted cancer or stem cell of human origin. FOXN1 gene encodes a transcription factor essential for the development and function of thymic epithelial cells (TECs), the primary lymphoid organ that supports T-cell development and selection. In this study, we are going to produce the FOXN1 KO SCID pigs using the Crispr/Cpf1 method. Porcine genomic DNA sequences were analyzed and the target sequences were selected using a web tool, Benchling (https://benchling.com/). The designed crDNA oligos was synthesized by the Oligonucleotide Synthesis Service (Macrogen Inc., Seoul, Korea). To generate the AsCpf1-mCherry-Puro construct, pTE4396 (#74041; Addgene, Cambridge, MA, USA) was modified by removing the NeoR/KanR sequence using BstBI and SmaI. Then, the mCherry-Puro sequence from pSicoR-Ef1a-mCh-Puro (#31845; Addgene, Cambridge, MA, USA) digested with the same restriction enzymes was inserted into the aforementioned NeoR/KanR-deleted vector. The crDNA #1 or crDNA #2 was inserted into the pTE4396 and AsCpf1-mCherry-Puro vectors in the U6 promoter region using BsmBI enzyme, respectively. The two vectors were transfected with lipofectamine 3000 (Life Technologies, Grand Island, NY, USA) and selected with puromycin and G-418 antibiotics. As a result, we established a cell line into which two vectors (pTE4396+crFOXN1#2 and AsCpf1- mCherry-Puro+ crFOXN1#1) and were inserted. Further studies are needed to characterize FOXN1 KO cell lines.
Growth differentiation factor8 (GDF8) is a member of the transforming growth factor-β that has been identified as a strong physiological regulator. Overall of the current studies, the GDF8 is detected in oviduct fluid and uterus which led us to suggest that the GDF8 may effect on preimplantation embryonic development and act paracrine role to correlate with successful late-blastocyst implantation in in vivo. The purpose of this study is the effects of GDF8 on porcine parthenogenesis (PA) embryo development during in vitro culture (IVC). We were investigated the effect of GDF8 supplement during PA embryo IVC by cleavage and blastocyst formation rate and patterning analysis. Data were analyzed by on way ANOVA, followed by Tukey’s range test. Respectively 0.2, 2 and 20 ng/mL of GDF8 were added during IVC followed experiment design as control, 0.2, 2, and 20 GDF8 supplement groups. After 48h of embryo culture time, no significant difference was observed on cleavage rate from the different concentration (0, 0.2, 2, and 20 ng/ml) of GDF8 supplement groups (65.7%, 66.0%, 66.3%, and 65.8%, respectively). After 120h of embryo culture time, the 0.2 and 2 group showed significantly (p<0.05) higher blastocyst formation rate than control (40.4% and 36.4% VS 40.4%, respectively). In embryo developmental pattern analysis, the 0.2 ng/ml GDF8 supplement groups showed significantly higher (p<0.05) 2-3 cell cleavage- and early blastocyst pattern compared with control (12.0% and 10.4% VS 6.6% and 6.2%, respectively). However there are no significantly different pattern was observed in other groups. In conclusion, the 0.2 ng/ml of GDF8 supplementation during porcine PA embryo IVC significantly changed embryonic developmental patterns. However there are further studies are required such as analysis of blastocyst total number, specific gene transcription pattern, and ICM/TE rate to make clarify and support the conclusion.
The use of pigs in neuroscience has increased over the past years because the pigs are closely related to humans in terms of anatomy and physiology. Especially, the blood-brain barrier (BBB) maintains the homeostatic microenvironment in the central nervous system (CNS) and they can provide a valuable tool for studying the neurobiology. However, only a few putative blood-brain barrier (BBB) models have been generated by co-culture of porcine primary cells. The fundamental problem is that they lose some of their phenotypes when maintained in vitro for long-term culture. To establish improved in vitro porcine BBB models, we differentiated novel brain microvascular endothelial cells (BMECs) from porcine induced pluripotent stem cells (iPSCs) using a modified human-based protocol. Briefly, the dissociated single cells from iPSCs were seeded in Geltrex. For differentiation, cells were maintained for 3 days of expansion and then switched to unconditioned medium (UM) lacking bFGF for 6-7 days. Then, we subcultured cells onto collagen/fibronectin coated plates and changed BMEC medium for 2-3 weeks. About two weeks later, we observed a cluster of round cells surrounded by spindle shaped adherent cells termed as colony-forming units (CFU) of putative BMECs. Over time, the cluster of cells disappears and remained adherent spindle-shaped cells showed properties of endothelial cells. Although further studies will be needed, this study would be a great comparative analysis of the porcine and human in vitro BBB model.
Growth differentiation factor 8 (GDF8) is a member of the transforming growth factor-β that has been identified as a strong physiological regulator. The purpose of this study is to investigate the effects of GDF8 on porcine oocytes during in vitro maturation (IVM). We investigated a specific gene transcription levels in oocytes and cumulus cells (CC) after IVM by realtime PCR arry, and specific protein expression and activation levels in matured CCs by western blotting. Each concentration (0, 1, 10, and 100 ng/ml) of GDF8 was added in maturation medium (TCM199) during process of IVM. Data were analyzed by ANOVA followed by Duncan using SPSS (Statistical Package for Social Science). Data are presented as the mean and Differences were considered significant at P < 0.05. After 44 h of IVM, oocytes are mechanically denuded from CCs with 0.1% of hyaluronidase, and then the separated oocytes and CCs were sampled following each group. To assess the effect of GDF8 on specific gene transcription level changes as a dose response during IVM, the realtime PCR array was performed. In CCs the 1- and 10 ng/ml of GDF8 supplement group showed the transcription co-factors CBP and SP1, cell metabolic regulator MAPK1, and cumulus expansion related genes Has2, Cox-2, Ptx3 and Areg transcription levels were significantly distinguished with control when hierarchically clustered by Euclidean distance with average linkage method after IVM. In matured oocytes the 10- and 100 ng/ml of GDF8 supplement group showed the maternal factors JMJD3 and Zar1, transcriptional regulator FOXO1, Sirt1 and Sirt2, mitochondrial activity factor Sirt3, ACSL3 and ACADL, anti-apoptosis gene BCL-2, and oocyte secrete factor BMP15 mRNA transcription levels were significantly distinguished compared with control. To determine effect of GDF8 supplement during IVM, the GDF8 down steam canonical regulator SMAD2/3 protein phosphorylation levels analyzed in CCs by western blotting. The 10- and 100 ng/ml supplement groups showed significantly increase phosphorylated (P)-SMAD3 (1.56 and 1.34 times higher than control) protein levels (P < 0.05). In conclusion, supplement of GDF8 during IVM activates FOXO homolog transcription and induced cumulus cells expansion via activation of SMAD3 signaling in CCs. While process of IVM, the transcriptional landscape changes in CCs may consequently result maternal factors accumulation and mitochondrial activation in oocytes.
Little is known to date about neural development of pig and directed differentiation of porcine pluripotent stem cells (PSCs) to neuronal cells remains elusive. To determine whether soluble factors from glioblastoma multiforme (GBM) promoted the neural differentiation from porcine induced PSCs (iPSCs), cells were treated cultured media of GBM cells. First of all, we isolated and established primary GBM cell line (WHO grade IV). The cellular morphology of GBM cancer cell line are dendritic-like with positive expression in NESTIN, SOX2, VIMENTIN and GFAP using immunofluorescence analysis. G-banded karyotype from primary GBM cell line revealed severe numerical chromosomal aberrations. GBM-cultured medium (CM) treated iPSC-NPCs survive well in vitro when supplemented with a combination of growth factors, including EGF and bFGF. The GBM-CM treated differentiated cells showed an increased mRNA expression level of astrocyte marker, GFAP and the dopaminergic neuron marker, tyrosine hydroxylase (TH). However, there was no significant difference in mRNA expression level of oligodendrocyte marker, MBP. The protocol developed in the present study for large animal models might provide an exciting tool to bridge the present gaps in neuroscience studies between rodents and humans.
A meningioma is the second most common primary intracranial tumor of the central nervous system. One critical obstacle in meningioma research and preclinical development of novel therapeutic agents is a relative lack of suitable preclinical in vitro and in vivo model systems. In the current study, we assessed the proliferative characteristics of patient derived five primary meningioma cancer cell lines (WHO grade I and II) from brain tumor lesions. All of the meningioma cell lines showed homogenous expression of meningioma marker, VIMENTIN. The GTG-banding analysis determined the existence of different patterns of chromosomal abnormalities in representative cancer cell lines. The almost of the meningioma cell lines showed homogeneously spindle shaped cells, except for M160425 which have two prominent cell morphologies, spindle and round. Population-doubling (PD) was measured for every passage. The M160425 cell line had significantly longer PD time (39.8 ± 0.9 h, P<0.05) than the other meningioma cell lines. Consistent with the PD time, we confirmed that mRNA expression of Ki67, the conventional proliferation marker, was significantly lower in M160425 cell line compared to the other cell lines. The correlation between the PD time and the abundance of Ki67 in the meningioma derived cell lines was negative, indicating higher Ki67 abundance and a shorter PD time. The patient derived meningioma cancer cell lines established in this study might contribute to understanding cancer biology and help the success in the clinic by explaining the slightly different clinical behavior among the patients.
In mature oocytes, maturation promoting factor (MPF) activity is playing important roles in arrest at M-phase and its continuous phenomenon, oocyte aging. In most mammals, metaphase II oocytes show high MPF activity and have been used as ooplasts in somatic cell nuclear transfer (SCNT). Caffeine has been found to regulate MPF activity in mammalian oocytes. Caffeine inhibits p34cdc2 phosphorylation and increases MPF activity. The present study investigated the effects of caffeine treatment during last 4 hours of in vitro maturation (IVM) on oocyte maturation and embryonic development after parthenogenesis (PA) and SCNT. The IVM medium was medium-199, 10% (v/v) PFF, cysteine, pyruvate, epidermal growth factor, kanamycin, insulin, and hormones. Immature oocytes were matured in IVM medium without or with 2.5 mM caffeine during the last 4 hours of IVM. The in vitro culture medium for embryonic development was porcine zygote medium-3 containing 0.3% (w/v) bovine serum albumin. Nuclear maturation (83.6–87.2%) and intraoocyte glutathione contents (0.9–1.0 pixels/oocyte) of oocytes were not influenced by the caffeine treatment. The membrane fusion of cell-cytoplast couplets (75.5–76.5%) and cleavage (85.4–86.2%) were also not altered by the caffeine treatment. However, caffeine-treated oocytes showed higher (P<0.05) blastocyst formation after SCNT (47.5 vs. 34.3%) than untreated oocytes. Our results demonstrate that caffeine treatment during last 4 hour of IVM improves the developmental competence of SCNT embryos probably by influencing MPF activity.
Mitochondrial dysfunction is found in oocytes and transmitted to the offspring due to maternal obesity. This is curable by endoplasmic reticulum (ER) stress inhibitors such as salubrinal (SAL). Recently pigs are considered as a model animal for biomedical research due to its physiological similarity with human. Pig oocytes have shown ER stress mostly in metaphase II stage. ER stress is hindering the in vitro embryo production (IVP). This study investigated the effect of ER stress inhibition by using SAL during 44 h of in vitro maturation (IVM) of oocytes at 1, 10, 50 and 100 nM concentrations. Firstly, we defined the concentration of SAL during IVM of pig oocytes. SAL at 10 nM showed higher (44.2 to 55.6%, P<P0.05) development competence to the blastocyst state than control and other concentrations after parthenogenetic activation (PA). Secondly, we sorted out the time-dependent treatment at 10 nM of SAL for IVM of oocytes. It revealed that treatment with SAL during 22 to 44 h and 0 to 44 h of IVM improved PA embryonic development significantly (40.5, 51.7 and 60.2% for control, 22 to 44 h and 0 to 44 h of IVM, respectively, P<0.05). Glutathione (GSH) level is an indicator of cytoplasmic maturation of oocytes. Reactive oxygen species (ROS) have a harmful effect on development competence of oocytes. For this, we determined the intraoocyte levels of GSH and ROS after 44 h of IVM. It was found that SAL increased intraoocyte GSH level and also decrease ROS level (P<0.05). Finally, we performed somatic cell nuclear transfer (SCNT) after treating oocytes with 10 nM SAL during IVM. SAL treatment significantly improved blastocyst formation of SCNT embryos compared to control (24.7 vs. 39.6%, P<0.05). Our results indicate that treatment of pig oocytes with ER stress inhibitor SAL during IVM improves preimplantation development cloned pig embryos by influencing cytoplasmic maturation in terms of increased GSH content and decreased ROS level in IVM pig oocytes.
Growth differentiation factor 8 (GDF8) is a member of the transforming growth factor-β that has been identified as a strong physiological regulator. The purpose of this study is to investigate the effects of GDF8 on porcine oocytes during in vitro maturation (IVM). We investigated a specific gene transcription levels in oocytes and cumulus cells (CC) after IVM, and protein kinase B (PKB) expression and activation levels in matured CCs by western blotting. Each concentration (0, 1, 10, and 100 ng/ml) of GDF8 was treated in maturation medium (TCM199) while process of IVM. Data were analyzed by ANOVA followed by Duncan using SPSS (Statistical Package for Social Science). Data are presented as the mean and differences were considered significant at P < 0.05. After 44 h of IVM, oocytes are mechanically denuded from CCs with 0.1% of hyaluronidase, and then the separated each group of oocytes and CCs were sampled. To assess the effect of GDF8 on specific gene transcription level changes as a dose response during IVM, the realtime PCR was performed. In CCs, all of GDF8 treatment groups showed significantly higher CREB transcription regulator cbp mRNA and the 1- and 10 ng/ml treatment groups observed significantly increased cumulus expansion related genes areg, cox-2, has2, ptx3 and tnfaip6 transcription levels after IVM. In matured oocytes, the maternal factors jmjd3 and zar1, transcriptional regulator foxo1 and sirt1, mitochondrial activity factor sirt3 and acadl, and anti-apoptosis gene bcl-2 mRNA transcription levels were significantly increased in 1- and10 ng/mL of GDF8 treatment groups compared with control. To determine effect of GDF8 treatment during IVM, translation regulator PKB protein expression and phosphorylation levels were analyzed in CCs by western blotting. The 10 ng/ml treatment group showed significantly increased phosphorylated PKB (1.4 times higher than control) protein levels (P < 0.05). In conclusion, treatment 10 ng/ml of GDF8 during IVM activates CREB related transcription and induced cumulus cells expansion via activation of PKB signaling in CCs. The transcriptional landscape changes in CCs result maternal factors accumulation and mitochondrial activation in oocytes during IVM.
(-)-Epicatechin gallate (ECG) is a polyphenol compound of green tea exhibiting biological activities, such as antioxidant and anticancer effects. To examine the effect of ECG on porcine oocytes during in vitro maturation (IVM), oocytes were treated with 0-, 5-, 15-, and 25 μM ECG. After maturation, we investigated nuclear maturation, intracellular glutathione (GSH) and reactive oxygen species (ROS) levels and subsequent embryonic development after parthenogenetic activation (PA) and in vitro fertilization (IVF).
After 42 hours of IVM, the 5 μM group exhibited significantly increased (p< 0.05) nuclear maturation (89.8%) compared with the control group (86.1%). However, the 25 μM group observed significantly decreased (p< 0.05) nuclear maturation (83.5%). In intracellular maturation assessment the 5-, 15-, and 25 μM groups had significantly increased (p< 0.05) GSH levels and decreased ROS levels compared with the controls. The 5- and 15 μM group showed significantly increased (p< 0.05) embryo formation rates and total cell number of blastocysts after PA (18% and 68.9, 15% and 85.1 vs. 12% and 59.5, respectively) compared with controls. Although the 25 μM group observed significantly lower blastocyst formation rates after PA (27.6% vs. 23.2%) than control group, the 5 μM group showed significantly increased blastocyst formation rates after PA (37.2% vs. 23.2%) compared to the control group. Furthermore, the 5 μM group measured significantly increased blastocyst formation rates (20.7% vs. 8.6%) and total cell number after IVF (88.3±1.5 vs. 58.0±3.6) compared to the control group.
The treatment of 5 μM ECG during IVM affectively improved the porcine embryonic developmental competence by regulating intracellular oxidative stress during IVM.
Klotho (KL) is a single transmembrane protein composed of KL1 and KL2 repeats possessing β-glucuronidase activity and maintains calcium homeostasis in physiological state. It has been implicated in pigs that calcium is important for the establishment and maintenance of pregnancy, and our previous study has shown that transient receptor potential vanilloid type 6 (TRPV6), a calcium ion transporter, is predominantly expressed in the uterine endometrium during pregnancy in pigs. However, expression and function of KL in the uterine endometrium has not been determined in pigs. Thus, the present study determined expression and regulation of KL in the uterine endometrium during the estrous cycle and pregnancy in pigs. Real-time RT-PCR analysis showed that levels of KL mRNA decreased between Days 12 to 15 of the estrous cycle, and its expression showed a biphasic manner during pregnancy. KL mRNA was expressed in conceptuses and in chorioallantoic tissues during pregnancy. Explant culture study showed that expression levels of KL were not affected by treatment of steroid hormones or interleukin-1beta during the implantation period. Furthermore, levels of KL mRNA in the uterine endometrium from gilts carrying somatic cell nuclear transfer (SCNT)- derived embryos were significantly lower than those from gilts carrying natural mating-derived embryos on Day 12 of pregnancy. These results exhibited that KL was expressed at the maternal-conceptus interface in a pregnancy statusand stage-specific manner, and its expression was affected by SCNT procedure, suggesting that KL may play an important role in the establishment and maintenance of pregnancy in pigs.
This study was designed to evaluate the effect of bovine serum albumin (BSA) in a maturation medium on oocyte maturation and embryonic development in pigs. Immature pig oocytes were matured for 44 h in a medium supplemented with 0.4% (w/v) BSA, 0.1% (w/v) polyvinyl alcohol (PVA), or 10% (v/v) pig follicular fluid (PFF). After IVM, oocytes reached metaphase II stage were activated for parthenogenesis (PA) or used as cytoplasts for somatic cell nuclear transfer (SCNT). Nuclear maturation (89.5%, 90.7% and 91.3% for BSA, PVA and PFF, respectively) and intraoocyte glutathione contents (1.20, 1.16 and 1.00 pixels/oocyte for BSA, PVA and PFF, respectively) were not altered by the macromolecules added to maturation medium. IVM of oocytes in a medium containing BSA (21.4%) and PVA (20.7%) showed significantly lower blastocyst formation after PA than culture in medium with PFF (39.2%). After SCNT, oocytes matured in medium with BSA showed decreased embryonic development to the blastocyst stage (9.2%) compared to those matured in medium with PFF (28.9%), while 23.6% of SCNT oocytes matured in medium with PVA developed to the blastocyst stage. When the effect of BSA in a maturation medium during the first 22 h and the second 22 h of IVM in combination with PFF or PVA was examined, PVA-BSA showed a higher nuclear maturation (94.1%) than BSA-PFF (84.5%). However, there was no significant difference in the blastocyst formation among tested combinations (47.3, 52.2, 50.0, 44.4 and 49.0% for PFF-PFF, PFF-BSA, PVA-BSA, BSA-PVA and BSA-PFF, respectively). Our results demonstrate that BSA and PVA added to maturation medium can support oocyte maturation comparable to PFF-supplemented medium. However, maturation of oocytes in a BSA-containing medium decreases embryonic development after PA and SCNT when compared with the medium supplemented with PFF.
Recent 2 decades, including in vitro maturation (IVM), assisted reproductive technologies (ARTs) achieved noteworthy development. However the efficiency of ARTs with in vitro matured oocytes is still lower than that with in vivo oocytes. To overcome those limitations, many researchers attempted to adapt co-culture system during IVM and consequently maturation efficiency has been increased. The beneficial effects of applying co-culture system is contemplated base on communication and interaction between various somatic cells and oocytes, achievement of paracrine factors, and spatial effects of extracellular matrix (ECM) from somatic cell surface. The understanding of co-culture system can provide some information to narrow the gap between in vitro and in vivo. Here we will review current studies about issues for understanding cu-culture system with various somatic cells to improve in vitro maturation microenvironment and provide bird view and strategies for further studies.
The objective of this study was to determine the effect of post-activation treatment with cytoskeletal regulators in combination with or without 6-dimethylaminopurine (DMAP) on embryonic development of pig oocytes after parthenogenesis (PA) and somatic cell nuclear transfer (SCNT). PA and SCNT oocytes were produced by using in vitromatured pig oocytes and treated for 4 h after electric activation with 0.5 μM latrunculin A (LA), 10.4 μM cytochalasins B (CB), and 4.9 μM cytochalasins D (CD) together with none or 2 mM DMAP. Post-activation treatment of PA oocytes with LA, CB, and CD did not alter embryo cleavage (85.8~88.6%), blastocyst formation (30.7~ 32.4%), and mean cell number of blastocysts (33.5~33.8 cells/blastocyst). When PA oocytes were treated with LA, CB, and CD in combination with DMAP, blastocyst formation was significantly (P<0.05) improved by CB+DMAP (42.5%) compared to LA+DMAP (28.0%) and CD+DMAP (25.1%), but no significant differences were found in embryo cleavage (77.5~78.0%) and mean blastocyst cell number (33.6~35.0 cells) among the three groups. In SCNT, blastocyst formation was significantly (P<0.05) increased by post-activation treatment with LA+DMAP (32.9%) and CD+DMAP (35.0%) compared to CB+DMAP (22.0%) while embryo cleavage (85.5~85.7%) and blastocyst cell number (41.1~43.8 cells) were not influenced. All three treatments (LA, CB, and CD with DMAP) effectively inhibited pseudo-polar body extrusion in SCNT oocytes. The proportions of oocytes showing single pronucleus formation were 89.6%, 83.9%, and 93.3%, respectively with the increased tendency (P<0.1) by LA+DMAP and CD+ DMAP compared to CB+DMAP. Our results demonstrate that post-activation treatment with LA or CD in combination with DMAP improves pre-implantation development of SCNT embryos and the stimulating effect of cytoskeletal modifiers on embryonic development is differentially shown depending on the origin (PA or SCNT) of embryos in pigs.
The objective of this study was to examine the effect of in vitro maturation (IVM) medium, cytochalasin B (CB) treatment during intracytoplasmic sperm injection (ICSI), and electric activation on in vitro development ICSI-derived embryos in pigs. Immature pig oocytes were matured in vitro in medium 199 (M199) or porcine zygote medium (PZM)-3 that were supplemented with porcine follicular fluid, cysteine, pyruvate, EGF, insulin, and hormones for the first 22 h and then further cultured in hormone-free medium for an additional 21~22 h. ICSI embryos were produced by injecting single sperm directly into the cytoplasm of IVM oocytes. The oocytes matured in PZM-3 with 61.6 mM NaCl (low-NaCl PZM-3) tended to decrease (0.05<P<0.1) nuclear maturation when compared with oocytes matured in M199 (76.9% vs. 83.8%) but no significant differences were found in embryo cleavage, blastocyst formation, and mean number of cells in blastocyst (73.8% vs. 74.6%, 11.1% vs. 12.1%, and 28.4 cells vs. 30.1 cells, respectively). The oocyte degeneration was not reduced by CB treatment during ICSI (11.9%) when compared with no treatment control (11.3%) while the treatment showed detrimental effects (P<0.05) on embryonic cleavage (40.0%) and blastocyst formation (1.8%) rates when compared with control (60.0% and 11.5%, respectively). For activation of ICSI oocytes, additional electric stimulus has no positive or negative effect on in vitro development of preimplantation stage ICSI porcine embryos. Our results demonstrate that CB treatment during ICSI inhibits embryonic development of ICSI oocytes and additional electric activation after ICSI has no effect in improving ICSI embryonic development in pigs. Further studies are needed to improve ICSI efficiency by investigating factors influencing embryonic development after ICSI in pigs.
The present study examined the histological characteristics of adult testis in the long-beaked common dolphin (Delphinus capensis) from Korean waters and the localization of DEAD-box polypeptide 4 (DDX4; a germ cell marker) and vimentin (a Sertoli cell marker) expression in the dolphin testis compared with that in terrestrial mammals, including dogs and rats. The seminiferous tubules of dolphin testis have very small or completely closed lumens, and spermatogenic cells and Sertoli cells within the tubules cannot be differentiated. Immunohistochemical analysis showed that, in the dolphin testis, DDX4- and vimentin-positive cells were scattered extensively within the tubule, whereas in the dog and rat testis, DDX4 immunoreactivity was localized in spermatogenic cells of the adluminal compartment, and vimentin immunoreactivity was localized in Sertoli cells of the basal compartment in the seminiferous epithelium. These results suggest that the histological characteristics of the seminiferous tubules in the dolphin testis differ from those of terrestrial species.