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Document type:
Zeitschriftenaufsatz
Author(s):
Berisha, B.; Bridger, P.; Toth, A.; Kliem, H.; Meyer, H.H.D.; Schams, D.; Pfarrer, C
Title:
Expression and localization of Gap Junctional Connexins 26 and 43 in bovine periovulatory follicles and in corpus luteum during different functional stages of oestrous cycle and pregnancy.
Abstract:
The aim of this study was to characterize the regulation of connexins (Cx26 and Cx43) in the bovine ovary (experiment 1–3). Experiment 1: ovaries containing preovulatory follicles or corpora lutea (CL) were collected at 0, 4, 10, 20, 25 (follicles) and 60 h (CL) relative to injection of GnRH. Experiment 2: CL were assigned to the following stages: days 1–2, 3–4, 5–7, 8–12, 13–16, >18 (after regression) of oestrous cycle and of early and late pregnancy (<4 and >4 months). Experiment 3: induced luteolysis, cows on days 8–12 were injected with PGF2a analogue (Cloprostenol), and CL were collected by transvaginal ovariectomy before and 0.5, 2, 4, 12, 24, 48 and 64 h after PGF2a injection. Real-time RT-PCR was applied to investigate mRNA expression and immunofluorescence was utilized for protein localization. Cx26 mRNA increased rapidly 4 h after GnRH injection (during LH surge) and decreased afterwards during the whole experimental period. Cx43 mRNA expression decreased continuously after GnRH application. Cx26 mRNA in CL increased significantly in the second part of oestrous cycle and after regression. In contrast, the highest mRNA expression for Cx43 in CL was detected during the early luteal phase. After induced luteolysis the mRNA expression of Cx26 increased significantly at 24 h. As shown by mmunofluorescence, Cx26 was predominantly localized in the connective tissue and blood vessels of bovine CL, whereas Cx43 was present in the luteal cells and blood vessels. This resulted in a strong increase of Cx26 expression during the late luteal phase and after luteal regression. Subsequently, Cx43 expression was distinctly decreased after luteal regression. These data suggest that Cx26 and Cx43 are involved in the local cellular mechanisms participating in tissue remodelling during the critical time around periovulation as well as during CL formation (angiogenesis), function and regression in the bovine ovary.
Journal title:
Reproduction in Domestic Animals
Year:
2009
Journal volume:
44
Pages contribution:
295-302
Language:
en
Fulltext / DOI:
doi:10.1111/j.1439-0531.2008.01068.x
WWW:
http://www.blackwell.de/
Print-ISSN:
0936-6768
TUM Institution:
Zentralinstitut für Ernährungs- und Lebensmittelforschung / Abteilung Physiologie
Format:
Text
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