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Molekulargenetische und proteinanalytische Untersuchungen trächtigkeitsassoziierter Glykoproteine beim Rind

dc.contributor.advisorTetens, Jens Prof. Dr.
dc.contributor.authorKrebs, Tony
dc.date.accessioned2022-10-11T14:24:33Z
dc.date.available2022-10-18T00:50:07Z
dc.date.issued2022-10-11
dc.identifier.urihttp://resolver.sub.uni-goettingen.de/purl?ediss-11858/14284
dc.identifier.urihttp://dx.doi.org/10.53846/goediss-9490
dc.description.sponsorshipDiese Arbeit wurde durch die Landwirtschaftliche Rentenbank und H. Wilhelm Schaumann Stiftung gefördert.de
dc.language.isodeude
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/
dc.subject.ddc630de
dc.titleMolekulargenetische und proteinanalytische Untersuchungen trächtigkeitsassoziierter Glykoproteine beim Rindde
dc.typedoctoralThesisde
dc.contributor.refereeTetens, Jens Prof. Dr.
dc.date.examination2020-11-26de
dc.description.abstractengThe dissertation addresses molecular genetic and protein analytical studies of bo-vine pregnancy-associated glycoproteins (boPAGs) and their practical application as pregnancy markers. Bovine PAGs are expressed by trophoblast cells in the placenta and are part of a multigene family that belongs to the group of aspartic proteases. The accumulation and circulation in maternal blood and milk have made boPAGs very useful and im-portant for pregnancy diagnosis in cattle during the last decades. However, the ex-act mechanisms of their formation and secretion as well as their physiological role during pregnancy remain largely unknown. In the first study of this dissertation (chapter 3), mRNA expression profiles were de-termined for selected modern (boPAG-1, -9, -21) and ancient (boPAG-2, -8, -10, -11, -12) bovine PAGs in cotyledon tissue. The highest expression was found for boPAG-8, the lowest for boPAG-10. Furthermore, it was found that boPAG-8 and -11 are signif-icantly higher expressed in early gestation (pregnancy days 20 - 90). In conclusion, they could have a possible role in placentation and the maintenance of early preg-nancy. The characterization of boPAG mRNA expression profiles provides an im-portant basis for the further comparison with proteomic data, especially during the early phase of pregnancy (time of placentation, change in the glycosylation pattern of boPAGs). Thus, they could contribute to gain new knowledge about the function of the boPAGs within this period. The second study of this dissertation (chapter 4) addresses the development and validation of a multiplexed parallel reaction monitoring (PRM) assay for the deter-mination of the relative protein abundances of 18 different boPAG during pregnancy and after calving. Furthermore, we investigated glycosylated and deglycosylated samples to detect possible effects of the glycosylation status on the used method and changes in the relative abundances. The significantly highest protein abundanc-es were found for boPAG-1 in both, glycosylated and deglycosylated samples. High-est degrees of glycosylation appeared in mid and late pregnancy samples as well as in afterbirth samples. Additionally, we identified a group of boPAGs (boPAG-3, -5, -6, -7, -8, -9, -15, -21) that seems not heavily glycosylated in any pregnancy stage. A linkage between the impact of glycosylation and potential N-glycosylation sites or phylogenetic relation was not detected. The PRM assay itself and the results of this study give new starting points to address further research on boPAG to better un-derstand the physiological role during pregnancy and achieve a real knowledge of these proteins. The third part of the thesis (chapter 5) describes the establishment of a new Sand-wich-ELISA which allows the simultaneous detection of boPAG in maternal serum and whole milk. Therefore, 984 serum and 928 milk samples were collected monthly from 231 Holstein Friesian cows from one week after insemination until six weeks postpartum. The ELISA is able to identify a cow as being pregnant at day 30 p. i. in serum and at day 40 p. i. in milk. The postpartum half-life of boPAG was estimated to be 6.4 days in serum and 7.1 days in milk. The amount of boPAG found in milk was 1.5 % of the amount of boPAG present in serum. Furthermore, the boPAG pro-file established during pregnancy in serum and milk showed a typical pattern. The developed ELISA quantifies boPAG concentrations in blood or whole milk samples in one ELISA system within a few hours. This is time saving for farmers and more effi-cient for laboratories, since only one test is necessary.de
dc.contributor.coRefereeLenz, Christof Dr.
dc.contributor.thirdRefereeBrenig, Bertram Prof. Dr. Dr.
dc.contributor.thirdRefereeHummel, Jürgen Prof. Dr.
dc.subject.engcattlede
dc.identifier.urnurn:nbn:de:gbv:7-ediss-14284-4
dc.affiliation.instituteFakultät für Agrarwissenschaftende
dc.subject.gokfullLand- und Forstwirtschaft (PPN621302791)de
dc.description.embargoed2022-10-18de
dc.identifier.ppn1818847973
dc.notes.confirmationsentConfirmation sent 2022-10-11T14:45:02de


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