Brassica campestris로부터 自家不和合性 관련 SLG⁴⁸ cDNA의 cloning 및 sequencing

Cloning and sequencing of SLG⁴⁸ cDNA related self-incompatibility in brassica campestris

A cDNA sequence homologous to the Brassica self-incompatibility locus specific glycoprotein sequence was isolated from stigmas of B. campestris plants homozygous for the SLG⁴⁸-allele. The relative molecular mass and isoelectric focusing value were calculated to be 50~60KD and pI 9.5, respectively. SLG⁴⁸ cDNA library consisting of 2.5×10⁵ recombinant clones was obtained from the poly (A)⁺ RNA. The cDNA were ligated to λZAPII arms. The selected cDNA clone was subcloned by in vivo excision using the helper phage R408 and E. coli (JM109). The resultant recombinant plasmid was sequenced with Sequenase Ver 2.0 and a deletion kit. The cDNA contains on open reading frame of 1137bases (379 amino acids), a non-coding 3’ region and a poly (A) tail, six N-glycosylation site. Overall the SLG⁴⁸ and SLG⁴⁵ or SRA⁰¹ sequences showed 80.4%, or 53.3% homology at the amino acid level. The SLG⁴⁸ sequence includes 12 cysteine residues in the carboxyl half of the molecule which are conserved with respect of the SLG⁴⁵ and SRA⁰¹. It is indicates that this common characterization of cysteine residues does not specify the self-incompatibility response.