MATER protein expression and intracellular localization throughout folliculogenesis and preimplantation embryo development in the bovine.
BACKGROUND
Mater (Maternal Antigen that Embryos Require), also known as Nalp5 (NACHT, leucine rich repeat and PYD containing 5), is an oocyte-specific maternal effect gene required for early embryonic development beyond the two-cell stage in mouse. We previously characterized the bovine orthologue MATER as an oocyte marker gene in cattle, and this gene was recently assigned to a QTL region for reproductive traits.


RESULTS
Here we have analyzed gene expression during folliculogenesis and preimplantation embryo development. In situ hybridization and immunohistochemistry on bovine ovarian section revealed that both the transcript and protein are restricted to the oocyte from primary follicles onwards, and accumulate in the oocyte cytoplasm during follicle growth. In immature oocytes, cytoplasmic, and more precisely cytosolic localization of MATER was confirmed by immunohistochemistry coupled with confocal microscopy and immunogold electron microscopy. By real-time PCR, MATER messenger RNA was observed to decrease strongly during maturation, and progressively during the embryo cleavage stages; it was hardly detected in morulae and blastocysts. The protein persisted after fertilization up until the blastocyst stage, and was mostly degraded after hatching. A similar predominantly cytoplasmic localization was observed in blastomeres from embryos up to 8-cells, with an apparent concentration near the nuclear membrane.


CONCLUSIONS
Altogether, these expression patterns are consistent with bovine MATER protein being an oocyte specific maternal effect factor as in mouse.
Pennetier
Sophie
S
Physiologie de la Reproduction et des Comportements, UMR 6175 Institut National de la Recherche Agronomique/Centre National de la Recherche Scientifique/Université François Rabelais de Tours/Haras Nationaux, F-37380 Nouzilly, France. pennetie@ifrance.com
Perreau
Christine
C
Uzbekova
Svetlana
S
Thélie
Aurore
A
Delaleu
Bernadette
B
Mermillod
Pascal
P
Dalbiès-Tran
Rozenn
R
D000818:Animals; D000906:Antibodies / Q000276:immunology / Q000302:isolation & purification; D001755:Blastocyst / Q000166:cytology* / Q000378:metabolism*; D002417:Cattle; D002454:Cell Differentiation; D004527:Egg Proteins / Q000235:genetics / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental; D007150:Immunohistochemistry; D046529:Microscopy, Electron, Transmission; D009865:Oocytes / Q000378:metabolism; D006080:Ovarian Follicle / Q000166:cytology* / Q000196:embryology / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics
D000906:Antibodies; D004527:Egg Proteins