Characterization of the porcine sperm adhesion molecule gene SPAM1- expression analysis, genomic structure, and...

Sequence analysis of cDNA products, derived from adult porcine testis mRNA, gave overlapping nucleotide sequence correlating to 1952 bp of the sperm adhesion molecule 1 (SPAM1) gene. This sequence was shown to be homologous to SPAM1 genes known in other mammalian species and contained an open reading frame encoding a 493-amino acid protein. Fluorescence in situ hybridization (FISH), using a bacterial artificial chromosome (BAC) clone from the PigE BAC library, was used to map SPAM1 to chromosome 18 of the pig. This finding is consistent with comparative mapping experiments performed between pig and human chromosomes. Polymerase chain reaction (PCR) analysis of genomic DNA has shown that the 1952 bp of cDNA sequence spans approximately 9 kb of genomic DNA and comprises of at least four exons, with its size and structure being relatively conserved between mouse, human and pig. Reverse transcriptase (RT)-PCR analysis of mRNA from nine porcine tissues has also suggested that expression of SPAM1 is limited to the testis.