Alternative splicing and mRNA expression analysis of bovine SLAMF7 gene in healthy and mastitis mammary tissues.

The signaling lymphocyte-activating molecule family 7 (SLAMF7) proteins serve as adhesion molecules on the surface of a variety of mature hematopoietic cells, and also partially control certain innate and adaptive immune responses. We characterized three novel bovine SLAMF7 splice variants, designated as SLAMF7-AS1, AS2, and AS3. All three novel SLAMF7 isoforms are derived from the complete transcripts (SLAMF7-complete) via alternative splicing (AS). The patterns of the three splice variants are exon skipping and alternative 5' splice sites. Bovine SLAMF7 transcripts are expressed in mammary tissue, as demonstrated by real-time PCR. The levels of the complete transcript expression in the normal mammary tissues were higher than that in Staphylococcus aureus (Staph. aureus)-induced mastitis mammary tissues. However, it was not significant for the mRNA expression level comparison between these two kinds of mammary. The SLAMF-AS2 isoforms are expressed the lowest levels among the three transcripts in both normal and infected mammary tissues. This study provides clues for a better understanding of bovine SLAMF7 gene function.