MEST (Mesoderm-specific transcript / Paternally expressed gene 1, member of the alpha/beta
hydroxylase fold family) is
paternally expressed in human fetal tissues (Kobayashi S et al, 1997). There are two
and initially only one (isoform 1) was shown to be imprinted (Kosaki K et al, 2000). Subsequently,
expression of the paternal allele of isoform 2 has been demonstrated in fetal kidney and placenta,
but not in 11 other fetal
tissues (Nakabayashi K et al, 2002). McMinn
J et al,
2006 also showed preferential expression of the paternal allele of isoform 2 in 10 out of 26
placentae, suggesting polymorphic imprinting. MEST (?isoform 2) is
biallelically expressed in adult blood (Riesewijk AM et al, 1997) and in breast
cancer (Pedersen IS et al, 1999; Pedersen
IS et al,
A maternally methylated germline DMR (reported in mouse) is located in the promoter of MEST
(chr7:129917976-129920347 NCBI build 36.1)(Lucifero
D et al, 2002).
See also MESTIT1 (MEST intronic transcript 1, PEG1-AS)
A separate transcript (MEST 3'UTR) that extends from the 3' end of MEST probably forms one of the
COPG2 antisense transcripts
(Yamasaki K et al, 2000).
In a study of 10 heterozygous in vitro-derived human preimplantation embryos, seven showed paternal
expression, two showed preferential paternal expression and one was biallelic. Further analysis of
61 preimplantation embryos showed eight embryos with bialleic expression consistent with polymorphic
imprinting. The authors provided evidence that polymorphic imprinting at MEST locus is attributable
to isoform 2 (Huntriss JD et al, 2013).
Baran Y et al (2015) found evidence of imprinting
of MEST (using RNA-seq) in multiple adult tissues (subcutaneous adipose, visceral adipose, tibial artery, mammary
tissue, lung, tibial nerve and fibroblasts). Allelic expression of MEST in other tissues was also consistent with
imprinting (EBV-transformed lymphocytes, pituitary, skeletal muscle, sun exposed skin, brain, uterus, aorta, left
ventricle, atrial appendage, cortex of kidney and not sun exposed skin).