| 1. |
- Hallberg, Ida, et al.
(author)
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Perfluorononanoic acid (PFNA) alters lipid accumulation in bovine blastocysts after oocyte exposure during in vitro maturation
- 2019
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In: Reproductive Toxicology. - : Elsevier BV. - 0890-6238 .- 1873-1708. ; 84, s. 1-8
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Journal article (peer-reviewed)abstract
- Perfluorononanoic acid (PFNA) is one of the perfluoroalkyl acids present in human tissues. In this study, effects on early embryo development after PFNA exposure were investigated using the bovine in vitro production system. Oocytes were exposed to PFNA during maturation in vitro (10 μg mL-1 and 0.1 μg mL-1), and then fertilized and cultured in parallel with control groups. Developmental parameters (cleavage, blastocyst formation) were followed and embryo quality evaluated (stage, grade). Embryos developed after exposure to 0.1 μg mL-1 were stained to distinguish nuclei, active mitochondria and neutral lipids. 10 μg mL-1 of PFNA had a severe negative effect on blastocyst formation (OR: 0.27 p < 0.05), an effect not observed at 0.1 μg mL-1. However, lipid droplet distribution was significantly altered in embryos exposed to 0.1 μg mL-1, suggesting a disturbance of lipid metabolism after exposure to sublethal levels of PFNA during oocyte maturation in vitro.
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| 2. |
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| 3. |
- Laskowski, Denise, et al.
(author)
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Insulin during in vitro oocyte maturation has an impact on development, mitochondria, and cytoskeleton in bovine day 8 blastocysts
- 2017
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In: Theriogenology. - : Elsevier BV. - 0093-691X .- 1879-3231. ; 101, s. 15-25
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Journal article (peer-reviewed)abstract
- Insulin is a key metabolic hormone that controls energy homeostasis in the body, including playing a specific role in regulating reproductive functions. Conditions associated with hyperinsulinemia can lower developmental rates in bovine in vitro embryo production and are linked to decreased fertility in humans, as in cases of obesity or type 2 diabetes. Embryo quality is important for fertility outcome and it can be assessed by choosing scoring standards for various characteristics, such as developmental stage, quality grade, cell number, mitochondrial pattern or actin cytoskeleton structure. Changes in the embryo's gene expression can reflect environmental impacts during maturation and may explain morphological differences. Together with morphological evaluation, this could enable better assessment and possibly prediction of the developmental potential of the embryo. The aim of this study was to use a bovine model to identify potential gene signatures of insulin-induced changes in the embryo by combining gene expression data and confocal microscopy evaluation. Bovine embryos were derived from oocytes matured in two different insulin concentrations (10 mu g mL(-1) and 0.1 mu g mL(-1)), then stained to distinguish f-Actin, DNA and active mitochondria. The total cell number of the embryo, quality of the actin cytoskeleton and mitochondrial distribution were assessed and compared to an insulin-free control group. A microarray-based transcriptome analysis was used to investigate key genes involved in cell structure, mitochondrial function and cell division. Our results indicate that insulin supplementation during oocyte maturation leads to lower blastocyst rates and a different phenotype, characterised by an increased cell number and different actin and mitochondrial distribution patterns. These changes were reflected by an up-regulation of genes involved in cell division (MAP2K2; DHCR7), cell structure (LMNA; VIM; TUBB2B; TUBB3; TUBB4B) and mitochondrial activation (ATP5D; CYP11A1; NDUFB7; NDUFB10; NDUFS8). Taken together, we hypothesise that the increased proliferation in the insulin-treated groups might impair the developmental potential of the embryos by inducing metabolic stress on the molecular level, which could be detrimental for the survival of the embryo. (C) 2017 Elsevier Inc. All rights reserved.
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| 4. |
- Gonzalez Herrero, Raquel, et al.
(author)
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Effect of blood plasma collected after adrenocorticotropic hormone administration during the preovulatory period in the sow on oocyte in vitro maturation
- 2013
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In: Theriogenology. - : Elsevier BV. - 0093-691X .- 1879-3231. ; 80, s. 673-683
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Journal article (peer-reviewed)abstract
- Reproduction may be affected by stressful events changing the female endocrine or metabolic profile. An altered environment during oocyte development could influence the delicate process of oocyte maturation. Here, the effect of simulated stress by media supplementation with blood plasma from sows after adrenocorticotropic hormone (ACTH) administration during the preovulatory period was assessed. Oocytes were matured for 46 hours in the presence of plasma from ACTH-treated sows, or plasma from NaCl-treated control sows, or medium without plasma (BSA group). The plasma used had been collected at 36 and 12 hours (+/- 2 hours) before ovulation (for the first 24 hours + last 22 hours of maturation, respectively). Subsequent fertilization and embryo development were evaluated. Actin cytoskeleton and mitochondrial patterns were studied by confocal microscopy both in the oocytes and the resulting blastocysts. Nuclear maturation did not differ between treatments. Subtle differences were observed in the actin microfilaments in oocytes; however, mitochondrial patterns were associated with the treatment (P < 0.001). These differences in mitochondrial patterns were not reflected by in vitro outcomes, which were similar in all groups. In conclusion, an altered hormonal environment provided by a brief exposure to plasma from ACTH-treated sows during in vitro oocyte maturation could induce alterations in actin cytoskeleton and mitochondria( patterns in oocytes. However, these changes might not hamper the subsequent in vitro embryo development. (C) 2013 Elsevier Inc. All rights reserved.
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| 5. |
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| 6. |
- Kunkitti, Panisara, et al.
(author)
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The ability of feline spermatozoa in different epididymal regions to undergo capacitation and acrosome reaction
- 2015
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In: Animal Reproduction Science. - : Elsevier BV. - 0378-4320 .- 1873-2232. ; 161, s. 64-74
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Journal article (peer-reviewed)abstract
- The sperm maturation process that occurs in the epididymis is a necessary process for spermatozoa to acquire motility and the ability to undergo capacitation, which is an important key for fertilization. The aim of this study was to evaluate the ability of feline spermatozoa from different regions of the epididymis to undergo capacitation and acrosome reaction. Experiment I: epididymal spermatozoa from caput, corpus and cauda regions were placed in phosphate buffered saline (control medium) and in vitro fertilization medium (capacitating conditions). Sperm motility, motility patterns, plasma membrane integrity and tyrosine phosphorylation were evaluated at time 0 and 60 min after incubation. Experiment II: spermatozoa were treated with 2 mu M of calcium ionophore (A23187) to induce the acrosome reaction and acrosome reaction was evaluated. The results showed a significant effect of region with a higher percentage of tyrosine phosphorylation in spermatozoa from the cauda than in the caput or corpus regions (P=0.0061; P=0.0088). Spermatozoa from corpus and cauda showed higher values in the majority of the measured motility parameters than spermatozoa from the caput (P<0.0001). Spermatozoa from all epididymal regions can undergo the acrosome reaction in vitro in response to induction by calcium ionophore with no difference between regions (P>0.05). Spermatozoa from all epididymal regions were able to undergo capacitation. Higher percentage of tyrosine phosphorylation in spermatozoa from the cauda reflect that they more easily underwent capacitation compared to spermatozoa from caput and corpus which required more time of incubation for capacitation. In conclusion feline epididymal spermatozoa from all regions can undergo capacitation and acrosome reaction in vitro and do not require incubation under capacitating conditions. (C) 2015 Elsevier B.V. All rights reserved.
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| 7. |
- Kunkitti, Panisara, et al.
(author)
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The tolerance of feline corpus and cauda spermatozoa to cryostress
- 2016
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In: Theriogenology. - : Elsevier BV. - 0093-691X .- 1879-3231. ; 85, s. 502-508
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Journal article (peer-reviewed)abstract
- Epididymal sperm preservation can be used to avoid the total loss of genetic material in threatened species. Spermatozoa from the corpus, as from the cauda, are motile and can undergo capacitation. Thus, they can potentially be preserved for assisted reproductive technologies. However, cryopreservation of spermatozoa has a direct detrimental effect on sperm quality. The aim of this study was to compare the chromatin stability and the survival rate of spermatozoa from the corpus and cauda epididymis after cryopreservation. Epididymal spermatozoa were collected and cryopreserved from the corpus and cauda of 12 domestic cats. Sperm motility, progressive motility, membrane integrity, acrosome integrity, and DNA integrity were evaluated before and after freezing thawing. The average total number of spermatozoa collected from the corpus was lower (10.2 x 10(6) +/- 7.4) than that from the cauda epididymis (24.9 x 10(6) +/- 14.4; P = 0.005). The percentage of spermatozoa with intact DNA did not differ significantly whether it was collected from the corpus or cauda regions and did not decrease after freezing thawing in either region. However, motility of spermatozoa from both regions was affected by the freezing thawing process with a significant decline in motility after thaw compared with fresh spermatozoa. A significant difference in the percentage of motile sperm between the corpus and cauda was observed after the freezing thawing process (P < 0.001). Although sperm motility was lower in postthaw spermatozoa from the corpus epididymidis than from the cauda, the rate of the reduction did not differ between regions. This study indicates that the cryopreservation process does not have a negative effect on chromatin stability of feline epididymal spermatozoa. Spermatozoa from the corpus region have a similar freezability as spermatozoa from the cauda region. Therefore, preservation of spermatozoa from the corpus and the cauda epididymidis might be of value in preserving genetic material from endangered or valuable felids. (c) 2016 Elsevier Inc. All rights reserved.
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| 10. |
- Sjunnesson, Ylva, et al.
(author)
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Single layer centrifugation-selected boar spermatozoa are capable of fertilization in vitro
- 2013
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In: Acta Veterinaria Scandinavica. - : Springer Science and Business Media LLC. - 0044-605X .- 1751-0147. ; 55
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Journal article (peer-reviewed)abstract
- Conclusion: The use of SLC does not adversely affect the in vitro fertilizing and embryo-generating ability of the selected spermatozoa compared to their unselected counterparts, but further modifications in the IVF conditions would be needed to improve the monospermy in IVF systems. Since SLC did not appear to have a negative effect on sperm fertilizing ability, and may in fact select for spermatozoa with a greater potential for fertilization, an in vivo trial to determine the usefulness of this sperm preparation technique prior to artificial insemination is warranted.
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