Fig. 1.
The MG6-Z transgene structure, the mouse mGluR6 genomic sequence around the potential transcription initiation site, and Northern blot analyses of transgenic mice. A, The MG6-Z transgene used for generation of transgenic mice was constructed from three different DNA fragments according to the procedures described under Materials and Methods. The restriction sites shown byarrows indicate the fusion sites; Sp,SphI; N, NaeI;H, HindIII; P,PstI; B, BamHI. TheSphI–NaeI fragment represents the mGluR6 upstream sequence. The HindIII–PstI fragment contains the gpt, trpS,lacZ, and SV40 sequences. ThePstI–BamHI fragment encodes the SV40 sequence. The region around the translation initiation site of the transgene is expanded below the MG6-Z transgene; theshaded region indicates the gpt andtrpS structures. The numbers shownbelow stand for nucleotide positions of the 5′ or 3′ termini of the fused genes. The ClaI (C)–SacI fragment was used as a labeled probe for Southern and Northern blot analyses. B, The nucleotide sequence around the potential transcription initiation site of the mouse mGluR6 gene is presented. The translation initiation site is boxed, and the NaeI site used for the transgene construction is indicated. The position corresponding to the transcription initiation site of the human mGluR6 gene (Hashimoto et al., 1997) is marked by an asterisk, and the position of the 5′ end of the rat mGluR6 cDNA clone containing the extreme 5′ sequence (Nakajima et al., 1993) is shown by anarrowhead. It is noted that the nucleotide sequences compared are highly homologous between the mouse and rat counterparts but diverge between the mouse and human counterparts. C, Northern blot analysis of poly(A+) RNA (2 μg) isolated from the cortex (lane 1), cerebellum (lane 2), brainstem (lane 3), and retina (lane 4) of the three transgenic mice. 18S and28S are ribosomal RNAs used as a marker RNA.