赤麂线粒体全基因组的序列和结构

提取赤麂细胞株总DNA，参照我们实验室已测定的同属动物小麂线粒体全基因组序列设计引物，PCR扩增、测序、拼接，获得赤麂线粒体全基因组序列并进行生物信息学分析。赤麂线粒体全基因组序列全长16354bp。定位了22个tRNA基因、2个rRNA基因、13个蛋白编码基因和1个D-loop区。赤麂与小麂及其它哺乳动物线粒体的基因组结构相同，它们的序列同源性都较高。

Sequence and organization of the complete mitochondrial genome of the Indian muntjac (Muntiacus muntjak)

We obtained the complete mitochondrial genome of Muntiacus muntjak by DNA sequencing based on the PCR fragments of 20 primers we designed. The complete mitochondrial genome was 16 354 base pairs (bp) in length, the same as that of M. reevesi and relatively small compared to other mammals. It contained genes for 22 transfer RNAs, 2 ribosomal RNAs and 13 protein coding genes, and it also had a displacement region. Those genes were arranged compactly with no introns and few intergenic nucleotides. We compared overall base compositions of the L strand of the 12 mammalian species' mitochondrial genomes,and found extreme A+T richness in the M. muntjak mitochondrial genome. The most represented base in the L strand was A (33 17), followed by T (28 98)>C (24 48)>G (13 37) and there was a strong bias of A+T at the third codon position relative to G+C. By nucleotide sequence alignment we compared the similarity between M. muntjak and other 11 mammalian species, and the percentage identity values showed that M. reevesi (93 8%) was the most similar to M. muntjak , followed by domestic cattle, Bos taurus (84 6%) and sheep, Ovis ovis (84 6%). Of 13 protein coding genes, the initiation codons of ND2, ND3 and ND5 were ATA and those of the other 10 protein coding genes were ATG. Most protein coding genes had a TAA termination codon but ND3, ND4 and COX3 had incomplete termination codons. We described the putative positions and lengths of restriction fragments and the tRNA ser s folded into their putative secondary structures. The dihydrouridine arm was unpaired in tRNA ser(AGN) . 12S rRNA and 16S rRNA showed extreme homology among the 12 mammals, higher than in any other protein coding gene. A putative gene organization for the M. muntjak mitochondrial genome was depicted, which was very similar to that of M. reevesi and other mammals. The sequence has been deposited in GenBank (Accession number NC_004563).