Table 1.

Epigenetic regulation of repetitive elements by chronic morphine administration

NameTypeOrigin% H3K9me2 binding relative to saline
HERVFH21IEndogenous retrovirusEutheria↓ (29)
LTR10AERV1Eutheria↑ (309)
MMERVK9C_IERV2Mus musculus↓ (79)
ETnERV2ERV2Mus↓ (73)
MYSERV6ERV2Muridae↓ (69)
RLTR13AERV2Mus musculus↓ (77)
ERVB4_1B-I_MMERV2Mus musculus↓ (74)
RLTR13A3ERV2Mus musculus↓ (69)
ETnERV3ERV2Mus↓ (66)
RLTR13A2ERV2Mus musculus↓ (72)
MMERVK9E_IERV2Mus musculus↓ (85)
RLTR12BD_MmERV2Mus↓ (61)
ORR1A4_LTRERV3Muridae↑ (117)
L1_Mur2_orf2L1Muridae↓ (78)
MusHAL1L1Mus↓ (73)
L1B_MML1Mus musculus↓ (83)
L1_Rod_5endL1Muridae↓ (26)
L1_Mur1_orf2L1Muridae↓ (82)
CYRA11_MMRepeat regionMus musculus↓ (83)
(TAAA)nSimple RepeatEukaryota↓ (21)
(GAAA)nSimple RepeatEukaryota↓ (40)
MIRSINEMammalia↓ (34)
MUSID3SINE2/tRNARodentia↓ (34)
tRNA–His–CAYtRNAVertebrata↓ (26)
  • Repetitive element alignment and analysis were accomplished as described previously (Maze et al., 2011). Briefly, we performed short reads alignment on the canonical repeat sequences and assessed the global quantitative change of H3K9me2 enrichment after chronic morphine administration. The majority of repetitive elements (22 of 24) showed decreased H3K9me2 enrichment after chronic morphine administration. Arrows represent increase or decrease in H3K9me2 binding relative to saline-treated animals, whereas numbers in parentheses represent percentage of H3K9me2 binding relative to saline controls.