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Träfflista för sökning "WFRF:(Sjunnesson Ylva) srt2:(2015-2019)"

Search: WFRF:(Sjunnesson Ylva) > (2015-2019)

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1.
  • Al-Essawe, Essraa M, et al. (author)
  • Seminal plasma influences the fertilizing potential of cryopreserved stallion sperm
  • 2018
  • In: Theriogenology. - : Elsevier BV. - 0093-691X .- 1879-3231. ; 115, s. 99-107
  • Journal article (peer-reviewed)abstract
    • Seminal plasma (SP) contains proteins that may influence cryosurvival and prevent capacitation-like changes due to freezing and thawing. The objective of this study was to investigate the effect of adding pooled SP from "good" (GF) or "bad" (BF) freezer stallions on sperm cells' fertilizing ability. "Good freezers" refers to stallions that usually produce ejaculates which can withstand cryopreservation, whilst "bad freezer" stallions produce ejaculates which cannot tolerate the freezing process. A heterologous zona binding assay with in vitro matured bovine oocytes was used to assess the binding ability of equine sperm cells as a possible alternative to artificial insemination trials. The effect of adding SP i) prior to cryopreservation; ii) after thawing of sperm cells selected by single layer centrifugation (SLC); iii) to capacitation medium, was evaluated. Adding SP from GE stallions prior to cryopreservation reduced the mean number of sperm cells bound to the zona pellucida (ZP) compared to control (P = 0.0003), SP-free sperm cells and group received SP from BF stallions (P < 0.0001 for both). After thawing SLC-selected sperm cells treated with 5% SP showed a decrease in binding ability compared with SP-free sperm cells (P < 0.0001). The binding affinity of sperm cells was higher in the group treated with SP from GF than with SP from BF stallions (P < 0.05). Prolonged exposure to SP impaired the ability of stallion sperm cells to undergo capacitation and bind to ZP, regardless of the source of SP (P < 0.0001). The response of equine sperm cells to SP is influenced by the ability of the sperm cells to withstand cryopreservation and is affected by the timing of exposure and the origin of SP. Customization of the protocol for individual stallions is recommended to optimize the effect. (C) 2018 Elsevier Inc. All rights reserved.
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2.
  • Gonzalez Herrero, Raquel, et al. (author)
  • Blood plasma collected after adrenocorticotropic hormone administration during the preovulatory period in the sow negatively affects in vitro fertilization by disturbing spermatozoa function
  • 2015
  • In: Theriogenology. - : Elsevier BV. - 0093-691X .- 1879-3231. ; 83, s. 1128-1139
  • Journal article (peer-reviewed)abstract
    • Successful fertilization is essential for reproduction and might be negatively affected by stressful events, which could alter the environment where fertilization occurs. The aim of the study was to determine whether an altered hormonal profile in blood plasma caused by adrenocorticotropic hormone (ACTH) administration could affect in vitro fertilization in the pig model. In experiment 1, gametes were exposed for 24 hours to plasma from ACTHtreated, non-ACTH-treated sows, or medium with BSA. Fertilization, cleavage, and blastocyst rates were lower in the ACTH group compared with the no ACTH or BSA control groups (P < 0.01). In experiment 2, the exposure of matured oocytes for 1 hour before fertilization to the same treatments did not have an impact on their ability to undergo fertilization or on embryo development. In experiment 3, spermatozoa were incubated for 0, 1, 4, and 24 hours under the same conditions. There was no effect of treatment on sperm viability. The percentage of acrosome-reacted spermatozoa remained higher in the ACTH group compared with the non-ACTH-treated group through the incubation period (P < 0.001). Protein tyrosine phosphorylation (PTP) patterns were also affected by treatment (P < 0.001). The presence of an atypical PTP pattern was higher in the ACTH group at all the analyzed time points compared with the BSA and no ACTH groups (P < 0.001). In conclusion, this altered environment may not affect oocyte competence but might affect the sperm fertilizing ability through alterations in the acrosome reaction and correct sequence of PTP patterns. (C) 2015 Elsevier Inc. All rights reserved.
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3.
  • Hallberg, Ida, et al. (author)
  • Perfluorononanoic acid (PFNA) alters lipid accumulation in bovine blastocysts after oocyte exposure during in vitro maturation
  • 2019
  • In: Reproductive Toxicology. - : Elsevier BV. - 0890-6238 .- 1873-1708. ; 84, s. 1-8
  • 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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7.
  • Kunkitti, Panisara, et al. (author)
  • In vitro fertilization using frozen-thawed feline epididymal spermatozoa from corpus and cauda regions
  • 2016
  • In: Theriogenology. - : Elsevier BV. - 0093-691X .- 1879-3231. ; 86, s. 1403-1408
  • Journal article (peer-reviewed)abstract
    • Epididymal sperm preservation offers a potential for rescuing genetic material from endangered or valuable animals after injury or death. Spermatozoa from corpus, as well as from cauda, have the capability to be motile and to undergo capacitation and can thus potentially be preserved for assisted reproductive technologies. In the present study, feline frozen-thawed epididymal spermatozoa from corpus and cauda regions were investigated for their ability to fertilize homologous oocytes and further embryo development in vitro. Epididymal spermatozoa from corpus and cauda of seven cats were cryopreserved and used for IVF. Cumulus-oocyte complexes (n = 419) were obtained from female cats after routine spaying. Frozen-thawed corpus epididymal spermatozoa showed similar properties of acrosome integrity, membrane integrity, and chromatin integrity as frozen-thawed spermatozoa from cauda except corpus spermatozoa showed lower motility (P < 0.05). The fertilizing capacity of frozen-thawed corpus epididymal spermatozoa was confirmed by similar number of embryos developing to the two- and four-cell stages compared with sperm from cauda (32.03% vs. 33.33%). However, oocytes fertilized with corpus spermatozoa had lower potential to develop to the blastocyst stage (6.79%) and had lower cell numbers compared to oocytes fertilized with cauda spermatozoa (14.08%). In conclusion, spermatozoa from corpus epididymis had a similar capability to fertilize homologous oocytes in vitro as sperm from cauda but resulted in fewer embryos developing to the blastocyst stage compared to spermatozoa from the cauda. (C) 2016 Elsevier Inc. All rights reserved.
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8.
  • Kunkitti, Panisara, et al. (author)
  • Osmotic tolerance of feline epididymal spermatozoa
  • 2017
  • In: Animal Reproduction Science. - : Elsevier BV. - 0378-4320 .- 1873-2232. ; 185, s. 148-153
  • Journal article (peer-reviewed)abstract
    • During the cryopreservation process, spermatozoa are exposed to hypertonic solutions contributed by the high concentration of cryoprotectant. During addition and removal of cryoprotectant the spermatozoa are subjected to a substantial osmotic stress. Spermatozoa of different I species and different stages of maturation may have different susceptibility to osmotic stress depending on the biology of the cell membrane and this will affect their tolerance to the freezing thawing stress. The aims of this study were to determine the osmotic tolerance limits for motility, membrane integrity and mitochondrial membrane potential of feline epididymal spermatozoa and to study the effect of osmotic stress on the feline spermatozoa of different epididymal regions. Epididymal spermatozoa from three regions (caput, corpus and cauda) were pre-exposed to various osmolalities (75, 300, 600, 900, 1200 mOsm) in a single step for 10 min and returned to 300 mOsm afterward. Percentage of motile spermatozoa was measured subjectively and membrane integrity (SYBR-14 positive cells) was evaluated prior to and after exposure to different osmolalities. The mitochondrial membrane potential (JC1) of spermatozoa were evaluated using flow cytometer and compared between epididymal regions (caput, corpus and cauda). All the parameters were compared using a mixed procedure. The, percentage of motile epididymal spermatozoa decreased significantly when spermatozoa were exposed to 75 mOsm and 600 mOsm. Epididymal spermatozoa showed signs of damage when pre-exposed to 900 and 1200 mOsm and returned to isotonic condition as significant reduction of membrane integrity and mitochondrial membrane potential were observed (P < 0.05). The plasma membrane of spermatozoa from the cauda epididymal region showed higher susceptibility to osmotic stress than the other regions as demonstrated by a significant difference between regions after return to isotonicity from 900 mOsm (P > 0.01) and a difference between caput and corpus after return from 1200 mOsm (P < 0.05). The corpus and cauda epididymal spermatozoa had higher percentage of spermatozoa with high mitochondrial membrane potential than those from caput when exposed to 75, 300 and 600 mOsm (P < 0.05). In conclusion, a single step exposure to hypertonic solution of greater than 600 mOsm prior to return to isotonic condition can cause severe damage to sperm membrane and mitochondrial membrane potential compared to non returning (exposure to various osmolality but not returned to isotonic condition). Changes in osmolality impacted mostly on sperm motility. Spermatozoa from cauda epididymis were more susceptible to osmotic stress compared to those from corpus and caput indicating that the maturation changes in the sperm membrane during passage through the epididymis increase susceptibility to the osmotic changes that may occur during sperm cryopreservation.
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9.
  • Kunkitti, Panisara, et al. (author)
  • The ability of feline spermatozoa in different epididymal regions to undergo capacitation and acrosome reaction
  • 2015
  • In: Animal Reproduction Science. - : Elsevier BV. - 0378-4320 .- 1873-2232. ; 161, s. 64-74
  • 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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10.
  • Kunkitti, Panisara, et al. (author)
  • The tolerance of feline corpus and cauda spermatozoa to cryostress
  • 2016
  • In: Theriogenology. - : Elsevier BV. - 0093-691X .- 1879-3231. ; 85, s. 502-508
  • 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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  • Result 1-10 of 38

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