Will circular DNA be reported?

[ZeweiSong]

Hi, we have found in our assembled results some contigs have identical first and last 141 bp, which is the longest kmer length we use. Can this kind of contigs be a real circular strucuture or simply an artifact?

For example, this is one of those contigs, the first and last 141 bps in bold:

ctg@k141_1642
AGCCGGCCCTGGGTCCGGTTGATCAGCACGGTGGTGTTCTGAAGCGACAGGAGGCTGTCGCGCACGGCAGCCGAAAGGGTGATCTCAGCCATTGCTGTACCTCGTTTCTAGGGTGCCCTCAACCGGGGCAATCGCTGCACGTGGAGGGATTCTCCCTCCGCGGCGGACGGTCATGAAGGCAGAGGTAAGCGGTGGGCAGCCGGTGCGTAAATTATCCACACGCATAAGGCCGCCGCGGCGCCCCCGCCGGCCAAGGAAAGGAGGGCGCCGGGCCCCCCTTTCCCGCCTAGGGCGATACCAGCCTAGCGGAAGAGCGCCAGGATCCCCTGCTCCGCCTGGCCGGCGAACGACAGGGCCTGGACGCCGAGCTGCTGGCGGGTCTGCAGGGCCAGCAGGTTGGCGCCTTCCTCGTTGAGGTCGGCCAGGGTCAGCTTGTCGGCGCCCGTCTGCAGGGTGTTCACGTAGCTCTCGGTGAACTCGAGACGGGTCTGCAGCAGCGCCACGTTGGAACCGAGGGTCTTGGTCTTGGTGCGCAAGGTGTCCAGGGCCGATTGAAGGTCGGTCACCAGGCCGTTGATTTCGGTGGTGAGCGTGGCGTCGATGTAGTACTGCCCGACAACGTCGCCAACGGTGATGCTGATGCCGGTGGTGATGCCCCCGAATTCCGCCTCACCGTCGCTGATTTTGCTGGCGACCTCGATGGTGAAGCTGAACGTTGTGCCCACGGCAATGACCTGGGTGAGGGCGAACGTAGTCGCCGTGGCCCCGCCGCCCACCGTGCCCACGCTGACGGTCACGGTATGGGTGCCGTAGAGGAACGTGAAATCGCCCGCGGCGCTGAAGGTGAAGGCGGTCGCGCCGGCATAGGTGATAGTGAGCGTCGAGCCGGTGGAGATGCTCACGCCGGTGGCGAAGTCATAGGACACGTTGAATGCTACATCACCGGTCAGCGCCACCGCCGTCAACGCGGTGCGGATGGCAAGGCCGGCGCCGCCTTCGGTCACGTCCACCGAATTGACGACCAGGGTGGACGAGGTGTCGGTGCTGAACTCGACCGTCAGCTTCTCGCCGGTGCCGTTGATCAGGTTCAGGCCCTGAAAGTCGGTGTCCTTGGCCAGGTTGGCGATCTGGAGGCGCAGGTCGTTGAACTGGCTGACCAGCTCGGCGATGGTGCTCGACGTCGCCGACTTGGCCGACACCGCGAGGCCCTTCATCTGGCGGACGATGGCGTCGATCGCCTCGGTGCCGTCCAGGGCCGCCGTCAGGCTGCTGATGCCCTGGTCGATGCCCGCCTTCTTGTCATCGAAGTCCGACGCCCGGTCGGCAAGGGTCTTCGCCTCGAAGAACTTGATCGGGTCGTCGATGGCGCTGGCCACCGACAGCCCGGTGGCCAGCCGGCCCTGGGTCCGGTTGATCAGCACGGTGGTGTTCTGAAGCGACAGGAGGCTGTCGCGCACGGCAGCCGAAAGGGTGATCTCAGCCATTGCTGTACCTCGTTTCTAGGGTGCCCTCAACCGGGGCAATCGCTGCACG

Thanks!

[alienzj]

[alienzj]

[alienzj]

It looks like this 141 bp sequence can not be identified from SRA microbe and fungi datasets.