Nlrp5 and Tle6 expression patterns in buffalo oocytes and pre-implantation embryos.

Maternal-effect genes (MEGs) accumulate in oocytes during oogenesis and mediate the pre-implantation embryo developmental programme until activation of the zygote genome. Nlrp5 and Tle6 are required for normal pre-implantation and embryonic development. However, the precise function of these MEGs in buffalo (Bubalus bubalis) remains to be elucidated. The aim of this study was to characterize Nlrp5 and Tle6 sequences and analyse their mRNA and protein expression patterns in somatic tissues, oocytes and pre-implantation embryos of buffalo. The coding sequences of each gene were successfully cloned and characterized. Real-time quantitative reverse transcription PCR results revealed an absence of Nlrp5 or Tle6 transcripts in somatic tissues, with the exception of ovary. Expression levels of Nlrp5 and Tle6 in oocytes increased from the germinal vesicle stage to metaphase II stage and then gradually decreased during morula and blastocyst stages. Protein expression patterns were confirmed by immunofluorescence analysis. This study lays a foundation for further validation of the function of MEGs in buffalo.