Figures (2)  Tables (6)
    • Figure 1. 

      Collinearity analysis of C. melo mitochondrial genome with other three Cucurbitaceae plants.

    • Figure 2. 

      The construction of phylogenetic tree among 14 species based on mitochondrial conserved genes.

    • FeatureValue
      Total length (bp)2,906,673
      Chromosome number3
      GC content44.77%
      Gene number88
      Protein genes40
      rRNA genes8
      tRNA genes40
      Genes with introns10
      Trans-spliced genes3
      Coding sequence1.54%
      Protein coding1.23%
      tRNAs and rRNAs0.31%
      Non-coding sequence98.46%
      Repetitive content44.2%
      SSRs0.1% (218)
      Tandem repeats (TRs)2.1% (653)
      Inverted repeats (IRs)2.4% (439)
      Forward repeats (FRs)39.4 (4,861)
      Chloroplast-like2.73%
      Nuclear-like48.62%

      Table 1. 

      The basic features of the C. melo mitochondrial genome.

    • SpeciesAmountC. melo
      C. lanatus7nad6-rps4; trnY-nad2; trnF-trnS; rps3-rpl16; sdh4-cox3-atp8; rrn5s-rrn18s; nad3-rps12
      C. sativus13nad6-rps4; nad9-rps1; nad2-sdh3; trnF-trnS; matR-trnH; rps3-rpl16; sdh4-cox3-atp8; rrn5S-rrn18S; rpl10-trnD; ccmFc-trnW-atp4; nad3-rps12; atp9-atp6
      C. pepo8nad6-rps4; nad9-rps1; rps3-rpl16; sdh4-cox3-atp8; rrn5S-rrn18S; nad3-rps12; atp9-atp6; trnM-trnG
      Gene clusters in bold are the gene clusters common to the four mitochondrial genomes.

      Table 2. 

      The gene clusters of melon collinearity with three other mitochondrial genomes.

    • FeatureC. meloC. lanatusC. sativusC. pepo
      Genome
      AccessionMG947207
      MG947208
      MG947209
      NC_014043NC_016004
      NC_016005
      NC_016006
      NC_014050
      Size in bp2,906,673379,2361,644,236982,833
      Chromosome number3131
      Topology StructureCircleCircleCircleCircle
      GC content (%)44.8%45.1%44.3%42.8%
      Gene
      Protein-coding genes40393738
      Protein-coding genes in bp (%)35,613 (1.23%)32,370 (8.5%)32,550 (3.31%)32,032 (3.26%)
      Single-copy protein genes37373737
      Single-copy protein genes in bp (%)34,080 (1.17%)31,986 (8.4%)32,550 (3.31%)31,806 (3.23%)
      Intron
      Trans-spliced5455
      Cis-spliced17201819
      Cis-spliced introns in bp (%)46,000 (1.6%)32,476 (8.6%)47,996 (2.9%)30,557 (3.1%)
      tRNA genes40182013
      Native17373
      Chloroplast-derived23151310
      Total tRNAs in bp (%)2,999 (0.1%)1,358 (0.4%)1,486 (0.09%)966 (0.1%)
      rRNA genes8363
      Total rRNAs in bp (%)5,815 (0.2%)5,148 (1.4%)11044 (0.67%)5,109 (0.5%)
      Noncoding regions in bp (%)2,862,246 (98.5%)340,360 (89.7%)1,599,156 (97.3%)944,726 (96.1%)
      Repetitive content
      SSR (num.)0.1% (218)0.2% (54)0.1% (144)0.2% (144)
      TR (num.)2.1% (653)0.3% (14)0.4% (120)1.9 (287)
      IR (pairs)2.4% (439)0.4% (14)6.3% (539)0.2% (17)
      FR (pairs)39.6% (4861)8.7% (209)37.3% (4974)22.1% (1608)
      Maximum large repeat length (bp)5,5327,28617,159621
      Number of repeats (>1 kb)871100
      Total repeats (%)44.2%9.6%44.1%24.4%
      Chloroplast-like in bp (%)79,463 (2.73%)28,703 (7.6%)70,702 (4.3%)113,347(11.5%)
      Mitochondrial-like in bp (%)967,450 (33.3%)159,032 (41.9%)907,251 (55.2%)180,008 (18.3%)
      Nuclear-like in bp (%)1,413,224 (48.62%)24,352 (6.4%)501,491 (30.5%)20,638 (2.1%)

      Table 3. 

      Mitochondrial genome summary of C. melo, C. sativus, C. pepo and C. lanatus

    • GeneC. meloC. lanatusC. sativusC. pepo
      Complex I
      nad1,2,3,4,4L,5,6,7,9++++
      Complex II
      sdh3+2++
      sdh4++++
      Complex III
      cob++++
      Complex IV
      cox1,2,3++++
      Complex V
      atp12+++
      atp4,6,8,9++++
      Cytochrome c biogenesis
      ccmB, C, Fc, Fn++++
      Ribosomal RNAs
      rrn5S6+2+
      rrn18S++2+
      rrn26S++2+
      Ribosomal proteins
      rpl2,5,16++++
      rpl10++
      rps1,3,4,7,10,12,13++++
      rps1922
      Other ORFs
      matR, mttB++++
      orf1,2+
      Total number48424341
      +: indicates the presence and uniqueness of this gene; −: represents the absence of this gene, and the number represents the copy number of this gene.

      Table 4. 

      Comparison of the gene content among C. melo, C. sativus, C. pepo and C. lanatus mitochondrial genome.

    • tRNAC. meloC. lanatusC. sativusC. pepo
      trnC-GCAMMMMM
      trnD-GUCCCMMC
      trnE-UUCMMMMM
      trnF-GAACMMCCCM
      trnfM-CAUMMM
      trnG-GCCCMMMMM
      trnH-GUGCCMCCCC
      trnI-CAUMMMM
      trnK-UUUMM
      trnL-CAACM
      trnM-CAUCCCMMMCMC
      trnN-GUUCCMMCC
      trnP-UGGMMMM
      trnQ-UUGMMMMMM
      trnR-ACGMM
      trnS-GCUMMM
      trnS-UGACM
      trnV-GACC
      trnW-CCACCCMMMMC
      trnY-GUAMMMM
      Choloroplast-derived17373
      Mitochondrial-derived23151310
      Total (type)40 (18)18 (15)20 (15)13 (13)

      Table 5. 

      Comparison of the tRNA genes.

    • OrderGenesC. meloC. lanatusC. sativusC. pepo
      1Atp14555
      2Atp411131213
      3Atp623222222
      4Atp82422
      5Atp95656
      6ccmB34343330
      7ccmC28272726
      8ccmFc17171817
      9ccmFn36363635
      10Cob16141614
      11Cox117171819
      12Cox213131313
      13Cox38987
      14matR12121212
      15mttB27242324
      16Nad121212120
      17Nad225252524
      18Nad312121210
      19Nad437383633
      20Nad4L13131313
      21Nad528272823
      22Nad615101010
      23Nad725272726
      24Nad97777
      25Rpl25332
      26Rpl5101098
      27Rpl165555
      28Rps13434
      29Rps37978
      30Rps417171718
      31Rps72222
      32Rps106565
      33Rps125777
      34Rps134334
      35Rps19pseudo3pseudo4
      36Sdh33435
      37Sdh44443
      Total507509498486
      Note: pseudo indicates that the gene is a pseudogene.

      Table 6. 

      Number of RNA editing sites in the four mitochondrial genomes.