Significance of aquaporins and sodium potassium ATPase subunits for expansion of the early equine conceptus
Autor: | Waltraud Tschulenk, M. Helmreich, Christine Aurich, Ingrid Walter, Fritz Pittner, Katharina Deichsel, S. Budik |
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Rok vydání: | 2008 |
Předmět: |
Embryology
Blotting Western Molecular Sequence Data Gestational Age Ectoderm Biology Aquaporins Kidney Concentrating Ability Endocrinology Microscopy Electron Transmission Pregnancy medicine Animals Conceptus Amino Acid Sequence Horses Kidney Tubules Collecting Yolk sac Na+/K+-ATPase reproductive and urinary physiology Yolk Sac Aquaporin 3 Base Sequence Reverse Transcriptase Polymerase Chain Reaction urogenital system Blastocoel Gene Expression Regulation Developmental Obstetrics and Gynecology Embryo Cell Biology Apical membrane Immunohistochemistry Molecular biology Aquaporin 5 Blastocyst medicine.anatomical_structure Reproductive Medicine embryonic structures Female Sodium-Potassium-Exchanging ATPase Endoderm |
Zdroj: | Reproduction. 135:497-508 |
ISSN: | 1741-7899 1470-1626 |
Popis: | Expansion of the equine conceptus can be divided into blastocoel and yolk sac phases. The endodermal layer transforming the blastocoel into the yolk sac is completed around day 8 of pregnancy. From that time, the size of the spherical conceptus increases tremendously due mainly to the accumulation of fluid rather than cell multiplication. In this study, we have investigated the abundance and localisation of Na(+)/K(+)-ATPases and aquaporins (AQP) in the equine conceptus on days 8, 10, 12, 14 and 16 by multiplex reverse transcriptase PCR, Western blot and immunohistochemistry. During conceptus expansion, the ectoderm of the yolk sac exhibited basolateral abundance of alpha1ATPase, apical localisation of AQP5, and membrane and cytoplasmic expression of AQP3. With increasing conceptus size its cells showed an extensive enlargement of the apical membrane surface by microvilli. From day 14 onwards, the yolk sac endoderm forms arc-like structures with attaching sites to the ectodermal layer and shows intensive staining for alpha1ATPase, AQP5 and AQP3 in the membrane as well as in the cytoplasm. In the yolk sac ectoderm, the arrangement of these proteins is comparable with the collecting ducts of kidney with AQP2 being replaced by the closely related AQP5. The detection of phosphorylation sites for protein kinase A suggests a similar AQP5 traffic and regulation as known for AQP2 in the collecting ducts of the kidney. The arrangement of these proteins in equine embryos indicates at least partially the mechanism of conceptus expansion. |
Databáze: | OpenAIRE |
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