Aktuelle Fragen zum schweizerischen und internationalen Kapitalmarktrecht - 17. Tagung zu Kapitalmarkt – Recht und Transaktionen – Tagungsband 2021

Der vorliegende Tagungsband „Kapitalmarkt – Recht und Transaktionen“ legt den Schwerpunkt wie jedes Jahr auf aktuelle Entwicklungen im Finanz- und Kapitalmarktrecht unter besonderer Berücksichtigung von Transaktionen in diesem Bereich. Das Jahr 2021 stand noch immer unter dem Eindruck der Corona-Pandemie, war aber auch geprägt durch dynamische technologische Weiterentwicklung sowie die noch immer fortschreitende Zunahme der Regulierung. Die Beiträge im vorliegenden Tagungsband befassen sich mit dem für die Schweiz neuen Phänomen der SPACS (special purpose acquisition companies), Lombardkrediten und Margin Calls, Streitigkeiten mit ESG-Bezug, der FIDLEG-Umsetzung im Bereich Corporate Finance, Neuerungen bei der Emittentenregulierung, der LIBOR Ablösung sowie dem neuen Institut des Kapitalbandes im revidierten Aktienrecht

Effects of the donor factors and freezing protocols on the bovine embryonic lipid profile

International audienceAbstract Embryo lipid profile is affected by in vitro culture conditions, that lead to an increase in lipids. Efforts have been made to optimize embryo lipid composition as it is associated with their quality. The objective of this study was to evaluate whether the diet supplementation of donor cows (n-3 or n-6 PUFA), or the slow freezing protocols (ethylene glycol sucrose EG-S vs. glycerol trehalose GLY-TRE), or the physiological stage of the donor (nulliparous heifers vs. primiparous lactating cows) may impact the bovine embryo lipid profile. Lipid extracts of 97 embryos were individually analysed by liquid chromatography-high resolution mass spectrometry, highlighting 246 lipids including 85% being overabundant in cow embryos compared to heifer embryos. Among 105 differential lipids, 72 were overabundant after EG-S protocol, including a single glycerophosphate PA(32:1) representing 27.3% of the significantly modulated lipids, suggesting that it is degraded when GLY-TRE is used. No lipids were different according to the n-3 or n-6 supplementation of the donor cows. In conclusion, the embryonic lipid profile was mainly affected by the physiological stage of the donors and the slow freezing protocols. The overabundance of lipids in lactating cow embryos and the resulting lower quality of these embryos is consistent with the lower pregnancy rate observed in cows compared to heifers. Unlike GLY-TRE protocol, EG-S freezing allowed to preserve glycerophospholipids potentially improving the slow freezing of in vitro-produced embryos. Further studies are required to modulate embryo quality and freezability by modulating the lipidome and integrating all stages of embryonic production

Lipid profile of bovine grade-1 blastocysts produced either in vivo or in vitro before and after slow freezing process

International audienceCurrently, in vitro embryo production (IVP) is successfully commercially applied in cattle. However, the high sensitivity of embryos to cryopreservation in comparison to in vivo (IVD) embryos slows the dissemination of this biotechnology. Reduced cryotolerance is frequently associated with lipid accumulation in the cytoplasm mainly due to in vitro culture conditions. The objective of this study was to evaluate the lipid composition of biopsied and sexed embryos, produced either in vivo or in vitro from the same Holstein heifers before and after a slow freezing protocol. Lipid extracts were analysed by liquid chromatography-high resolution mass spectrometry, which enabled the detection of 496 features. Our results highlighted a lipid enrichment of IVP embryos in triglycerides and oxidised glycerophospholipids and a reduced abundance in glycerophospholipids. The slow freezing process affected the lipid profiles of IVP and IVD embryos similarly. Lysophosphatidylcholine content was reduced when embryos were frozen/thawed. In conclusion, the embryonic lipid profile is impacted by IVP and slow freezing protocols but not by sex. Lysophosphatidylcholine seemed highly sensitive to cryopreservation and might contribute to explain the lower quality of frozen embryos. Further studies are required to improve embryo freezability by modulating the lipidome