Transposable Element Mapping – Olympia Oyster Genome Assembly using RepeatMasker 4.07

Steven wanted transposable elements (TEs) in the Olympia oyster genome identified.

After some minor struggles, I was able to get RepeatMasker installed on on both of our Apple Xserves (emu & roadrunner; running Ubuntu 16.04LTS).

Genome used: pbjelly_sjw_01

I ran RepeatMasker (v4.07) with RepBase-20170127 and RMBlast 2.6.0 four times:

  1. Default settings (i.e. no species select – will use human genome).

  2. Species = Crassostrea gigas (Pacific oyster)

  3. Species = Crassostrea virginica (Eastern oyster)

  4. Species = Ostrea lurida (Olympia oyster)

The idea was to get a sense of how the analyses would differ with species specifications. However, it’s likely that the only species setting that will make any difference will be Run #2 (Crassostrea gigas).

The reason I say this is that RepeatMasker has a built in tool to query which species are available in the RepBase database (e.g.):

RepeatMasker-4.0.7/util/queryRepeatDatabase.pl -species "crassostrea virginica" -stat

Here’s a very brief overview of what that yields:

  • Crassotrea gigas: 792 specific repeats

  • Crassostrea virginica: 4 Crassostrea virginica specific repeats

  • Ostrea lurida: 0 Ostrea lurida specific repeats

All runs were performed on roadrunner.

All commands were documented in a Jupyter Notebook (GitHub):

NOTE: RepeatMasker writes the desired output files (*.out, *.cat.gz, and *.gff) to the same directory that the genome is located in! If you conduct multiple runs with the same genome in the same directory, it will overwrite those files, as they are named using the genome assembly filename.


RESULTS:
RUN 1 (default settings – human genome)

Output folder:

Summary table (text):

Output table (GFF):

SUMMARY TABLE

==================================================
file name: jelly.out.fasta          
sequences:        696946
total length: 1253001795 bp  (1172226648 bp excl N/X-runs)
GC level:         36.51 %
bases masked:   20002806 bp ( 1.71 %)
==================================================
               number of      length   percentage
               elements*    occupied  of sequence
--------------------------------------------------
SINEs:            17794      1061170 bp    0.09 %
      ALUs          363        31340 bp    0.00 %
      MIRs         1166        92129 bp    0.01 %

LINEs:             4456       888114 bp    0.08 %
      LINE1         976       103929 bp    0.01 %
      LINE2         813        82891 bp    0.01 %
      L3/CR1        699        63627 bp    0.01 %

LTR elements:      1187       199118 bp    0.02 %
      ERVL          155        15828 bp    0.00 %
      ERVL-MaLRs    200        20737 bp    0.00 %
      ERV_classI    379        42833 bp    0.00 %
      ERV_classII    66         6896 bp    0.00 %

DNA elements:      2290       196866 bp    0.02 %
     hAT-Charlie    190        15468 bp    0.00 %
     TcMar-Tigger   732        37473 bp    0.00 %

Unclassified:       101        12946 bp    0.00 %

Total interspersed repeats:  2358214 bp    0.20 %


Small RNA:         5954       433422 bp    0.04 %

Satellites:         366        55705 bp    0.00 %
Simple repeats:  310641     14322152 bp    1.22 %
Low complexity:   47381      2844279 bp    0.24 %
==================================================

* most repeats fragmented by insertions or deletions
  have been counted as one element
  Runs of >=20 X/Ns in query were excluded in % calcs


The query species was assumed to be homo sapiens  
RepeatMasker Combined Database: Dfam_Consensus-20170127, RepBase-20170127
        
run with rmblastn version 2.6.0+

RUN 2 (species – Crassostrea gigas)

Output folder:

Summary table (text):

Output table (GFF):

SUMMARY TABLE

==================================================
file name: jelly.out.fasta          
sequences:        696946
total length: 1253001795 bp  (1172226648 bp excl N/X-runs)
GC level:         36.51 %
bases masked:  160759267 bp ( 13.71 %)
==================================================
               number of      length   percentage
               elements*    occupied  of sequence
--------------------------------------------------
Retroelements       213132     69887654 bp    5.96 %
   SINEs:             2374       311974 bp    0.03 %
   Penelope         171792     57862186 bp    4.94 %
   LINEs:           195605     63430615 bp    5.41 %
    CRE/SLACS            0            0 bp    0.00 %
     L2/CR1/Rex        731       357995 bp    0.03 %
     R1/LOA/Jockey       0            0 bp    0.00 %
     R2/R4/NeSL         13        11377 bp    0.00 %
     RTE/Bov-B        8085      1948581 bp    0.17 %
     L1/CIN4             0            0 bp    0.00 %
   LTR elements:     15153      6145065 bp    0.52 %
     BEL/Pao          2119       955773 bp    0.08 %
     Ty1/Copia         101        75372 bp    0.01 %
     Gypsy/DIRS1     11776      4815361 bp    0.41 %
       Retroviral        0            0 bp    0.00 %

DNA transposons     256292     35689117 bp    3.04 %
   hobo-Activator    19847      2059651 bp    0.18 %
   Tc1-IS630-Pogo    43269      6806311 bp    0.58 %
   En-Spm                0            0 bp    0.00 %
   MuDR-IS905            0            0 bp    0.00 %
   PiggyBac           7935      1060296 bp    0.09 %
   Tourist/Harbinger  9503       887332 bp    0.08 %
   Other (Mirage,        0            0 bp    0.00 %
    P-element, Transib)

Rolling-circles          0            0 bp    0.00 %

Unclassified:       174943     38299211 bp    3.27 %

Total interspersed repeats:   143875982 bp   12.27 %


Small RNA:             280        78768 bp    0.01 %

Satellites:           7383      1362194 bp    0.12 %
Simple repeats:     278809     12982714 bp    1.11 %
Low complexity:      44078      2622506 bp    0.22 %
==================================================

* most repeats fragmented by insertions or deletions
  have been counted as one element
  Runs of >=20 X/Ns in query were excluded in % calcs


The query species was assumed to be crassostrea gigas
RepeatMasker Combined Database: Dfam_Consensus-20170127, RepBase-20170127
        
run with rmblastn version 2.6.0+

RUN 3 (species – Crassostrea virginica)

Output folder:

Summary table (text):

Output table (GFF):

SUMMARY TABLE

==================================================
file name: jelly.out.fasta          
sequences:        696946
total length: 1253001795 bp  (1172226648 bp excl N/X-runs)
GC level:         36.51 %
bases masked:   39598953 bp ( 3.38 %)
==================================================
               number of      length   percentage
               elements*    occupied  of sequence
--------------------------------------------------
Retroelements        63882     10327611 bp    0.88 %
   SINEs:            63882     10327611 bp    0.88 %
   Penelope              0            0 bp    0.00 %
   LINEs:                0            0 bp    0.00 %
    CRE/SLACS            0            0 bp    0.00 %
     L2/CR1/Rex          0            0 bp    0.00 %
     R1/LOA/Jockey       0            0 bp    0.00 %
     R2/R4/NeSL          0            0 bp    0.00 %
     RTE/Bov-B           0            0 bp    0.00 %
     L1/CIN4             0            0 bp    0.00 %
   LTR elements:         0            0 bp    0.00 %
     BEL/Pao             0            0 bp    0.00 %
     Ty1/Copia           0            0 bp    0.00 %
     Gypsy/DIRS1         0            0 bp    0.00 %
       Retroviral        0            0 bp    0.00 %

DNA transposons       9433      2307292 bp    0.20 %
   hobo-Activator        0            0 bp    0.00 %
   Tc1-IS630-Pogo        0            0 bp    0.00 %
   En-Spm                0            0 bp    0.00 %
   MuDR-IS905            0            0 bp    0.00 %
   PiggyBac              0            0 bp    0.00 %
   Tourist/Harbinger     0            0 bp    0.00 %
   Other (Mirage,        0            0 bp    0.00 %
    P-element, Transib)

Rolling-circles          0            0 bp    0.00 %

Unclassified:        51558      9836468 bp    0.84 %

Total interspersed repeats:    22471371 bp    1.92 %


Small RNA:           64164     10406776 bp    0.89 %

Satellites:             10         5985 bp    0.00 %
Simple repeats:     298612     14185090 bp    1.21 %
Low complexity:      47510      2866522 bp    0.24 %
==================================================

* most repeats fragmented by insertions or deletions
  have been counted as one element
  Runs of >=20 X/Ns in query were excluded in % calcs


The query species was assumed to be crassostrea virginica
RepeatMasker Combined Database: Dfam_Consensus-20170127, RepBase-20170127
        
run with rmblastn version 2.6.0+

RUN 4 (species – Ostrea lurida)

Output folder:

Summary table (text):

Output table (GFF):

SUMMARY TABLE

==================================================
file name: jelly.out.fasta          
sequences:        696946
total length: 1253001795 bp  (1172226648 bp excl N/X-runs)
GC level:         36.51 %
bases masked:   17617763 bp ( 1.50 %)
==================================================
               number of      length   percentage
               elements*    occupied  of sequence
--------------------------------------------------
Retroelements            0            0 bp    0.00 %
   SINEs:                0            0 bp    0.00 %
   Penelope              0            0 bp    0.00 %
   LINEs:                0            0 bp    0.00 %
    CRE/SLACS            0            0 bp    0.00 %
     L2/CR1/Rex          0            0 bp    0.00 %
     R1/LOA/Jockey       0            0 bp    0.00 %
     R2/R4/NeSL          0            0 bp    0.00 %
     RTE/Bov-B           0            0 bp    0.00 %
     L1/CIN4             0            0 bp    0.00 %
   LTR elements:         0            0 bp    0.00 %
     BEL/Pao             0            0 bp    0.00 %
     Ty1/Copia           0            0 bp    0.00 %
     Gypsy/DIRS1         0            0 bp    0.00 %
       Retroviral        0            0 bp    0.00 %

DNA transposons          0            0 bp    0.00 %
   hobo-Activator        0            0 bp    0.00 %
   Tc1-IS630-Pogo        0            0 bp    0.00 %
   En-Spm                0            0 bp    0.00 %
   MuDR-IS905            0            0 bp    0.00 %
   PiggyBac              0            0 bp    0.00 %
   Tourist/Harbinger     0            0 bp    0.00 %
   Other (Mirage,        0            0 bp    0.00 %
    P-element, Transib)

Rolling-circles          0            0 bp    0.00 %

Unclassified:            3          189 bp    0.00 %

Total interspersed repeats:         189 bp    0.00 %


Small RNA:             282        79165 bp    0.01 %

Satellites:             10         5985 bp    0.00 %
Simple repeats:     313082     14662647 bp    1.25 %
Low complexity:      47785      2878201 bp    0.25 %
==================================================

* most repeats fragmented by insertions or deletions
  have been counted as one element
  Runs of >=20 X/Ns in query were excluded in % calcs


The query species was assumed to be ostrea lurida 
RepeatMasker Combined Database: Dfam_Consensus-20170127, RepBase-20170127
        
run with rmblastn version 2.6.0+

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