A mouse genomic library was screened with a human testicular H1 (H1t)
gene fragment. One phage containing the testis specific mouse H1t hist
one gene and its flanking regions was isolated. Northern blot analysis
showed that the mouse H1t gene is expressed only in mouse testis at t
he stage of pachytene spermatocytes and that the H1t mRNA is not polya
denylated. This mouse H1t gene encodes a protein wich differs from the
somatic mouse Hl proteins, but is similar to the known H1t proteins f
rom rat [1], and man [2].