SNURF, SNRPN, SNORD107 (HBII-436), SNORD64 (HBII-13), SNORD108(HBII-437), SNORD109A (HBII438A), SNORD116@ (PWCR1; HBII-85), SNORD115@ (HBII-52), SNORD109B (HBII438B), UBE3A-AS (incl. IPW,PAR-SN,PAR1,PAR5)
The SNURF-SNRPN transcript extends from SNURF to UBE3A (antisense) and spans 460 kb and 148 exons
RD et al, 2001; Runte
M et al, 2001). It is exclusively paternally expressed and contains:
An imprinting centre (IC) at its 5' end;
SNURF (SNRPN Upstream Reading Frame) that is encoded by exons 1-3 (Gray
TA et al, 1999);
SNRPN (small nuclear ribonucleoprotein polypeptide N) that is encoded by exons 4-10 (Glenn
CC et al, 1993;
JS et al, 1994);
Small nucleolar RNAs (snoRNAs) SNORD107 (HBII-436), SNORD64 (HBII-13), SNORD108(HBII-437), SNORD109A
(HBII438A), SNORD116@ (PWCR1; 24 copies of HBII-85), SNORD115@ (47 copies of HBII-52), and SNORD109B
(HBII438B) which are encoded within the introns (Cavaille
J et al, 2000; Runte
M et al, 2001; de
los Santos T et al, 2000);
IPW, a long noncoding RNA in the critical region of the PWS locus (it is also a regulator of the
DLK1-DIO3 imprinted region) (Wevrick
R et al, 1994; Stelzer Y et al,
And finally UBE3A-AS, the paternally expressed UBE3A antisense transcript (Rougeulle
C et al, 1998) that is thought to control the imprinting of UBE3A (Martins-Taylor K et al, 2014).
The extended transcript includes PAR-SN (Ning
Y et al, 1996), PAR1 and PAR5 (Sutcliffe
JS et al, 1994).
The transcript extends beyond SNORD116 in neurons but not in non-neuronal cells (Lee
S et al, 2003; Runte
M et al, 2004 ).
The germline imprint control region (DMR) overlaps exon 1 of SNRPN (Zeschnigk
M et al, 1997).
Using mouse A9 hybrids containing a single paternal or maternal chromosome, biased paternal
expression was found for the following ESTs within this extended transcript: H20970, R37082, R42946,
H59928, N21972, H17549, H75355 (Meguro
M et al, 2001).
Baran Y et al (2015) found evidence of imprinting
of SNURF (using RNA-seq) in multiple adult tissues (subcutaneous adipose, adrenal gland, aorta, coronary artery, tibial
artery, brain, mammary tissue, transverse colon, oesophagus muscularis, transformed fibroblasts, atrial appendage,
left ventricle, EBV-transformed lymphocytes, lung, skeletal muscle, tibial nerve, ovary, pituitary, not sun exposed skin,
sun exposed skin, stomach, thyroid, uterus and T cells). Allelic expression of SNURF in multiple other tissues was also
consistent with imprinting (pancreas, prostate, visceral adipose, vagina, fallopian tube, whole blood, liver and
oesophagus mucosa). Biallelic expression of SNURF was observed in testis tissue.