Abstract: MS1 gene is a tapetum-specific expressed gene related with male sterility in Arabidopsis thaliana. According to the coding sequences of Arabidopsis MS1 gene, a series of primers were designed to clone the homologous sequences in Brassica napus. PCR-Walking method was used to clone the full sequence of BnaX.MS1.a gene of Brassica napus. The total length of BnaX.MS1.a gene cloned here was 3 424 bp. The MS1 from Brassica napus shared a similarity of 89.5% in encoding sequence and 60.3% in full sequence with that from Arabidopsis thaliana. According to the results, it was deduced that it had an open reading frame (ORF) of 2 004 bp, encoding a protein of 667 amino acid, with protein molecular weight of 26 kD and isoelectric point of 8.01. The similarity between MS1 gene from Brassica napus and that from Arabidopsis thaliana was 93% in amino acid sequence. A plant expressed vector with the artificial miRNA was constructed for further studies on male sterility of Brassica napus.

Key words: MS1, BnaX.MS1.a, Brassica napus, amiRNA