A genome-wide approach reveals novel imprinted genes expressed in the human placenta

Figures & data

Table 1. Summary of newly identified imprinted genes

Gene	Chromosome	SNP	Localization	Monoallelic	Biallelic	Informative	Expressed	Murine	Score
	localization		SNP	heteroz.	heteroz.	mothers	allele	imprinting	(p value)
ZFAT	8q23–24	rs3739423	syn	9	0	2	paternal	no	0.06
		rs894344	syn	6	0	2	paternal
ZFAT-AS1	8q23–24	rs894343	exonic	10	0	3	paternal	NA	0.125
LIN28B	6q21	rs221635	3′UTR	9	0	2	paternal	no	0.01
		rs56042804	3′UTR	3	0	2	paternal
		rs71572246	3′UTR	4	0	2	paternal
ZNF597	16p13	rs12737, rs37824	3′UTR	7	0	3	maternal	no	0.125
GLIS3	9p24	rs6415788	non syn	11	0	6	paternal	no
ZC3H12C	11q22	rs1026608	syn	8	0	5	paternal	no	0.03
NTM	11q25	rs11634	3′UTR	3	1	1	maternal	-	0.5
MAGI2	7q21	rs13438302	syn	4	3	2	paternal	yes	0.25

The last column represents a statistical score estimated by a binomial law assuming that probability of inheriting any allele is 0.5.

Figure 1. Sequencing results of SNPs in the human ZFAT and ZFAT-AS1 genes. Imprinted expression was deduced by comparing genotypes of gDNA, cDNA and maternal gDNA, in placenta using SNPs rs rs3739423 (A), rs894344 (B) and rs894343 (C) and in lymphocytes (D).

Figure 2. Sequencing results of SNPs in the murine (A) and bovine (B) Zfat genes. Imprinted expression was deduced by comparing genotypes of gDNA, cDNA and maternal gDNA, in placenta and other tissues.

Figure 3. Sequencing results of SNPs in the murine Magi2 gene. Imprinted expression was deduced by comparing genotypes of gDNA, cDNA and maternal gDNA, in placenta and other tissues.

Figure 4. Real-time RT-PCR of ZFAT in human placentas. Expression of the ZFAT gene was compared between Controls (n = 17), IUGR (pregnancies with intrauterine growth restriction) (n = 16), PE (pregnancies complicated with preeclampsia) (n = 15) and PE + IUGR (n = 5), after normalization by the SDHA housekeeping gene. *p = 0,02, ** p = 0,002 in a group vs. the control group.

Figure 5. Immunohistochemistry to detect ZFAT on sections of human placentas. (A and B) (19 and 32 weeks of amenorrhea respectively) and (C) (fetal lung). (+) shows the detection with the primary antibody sc-87510 and (-) the negative control of detection without this antibody. Plain arrows show the strong labeling of endothelial cells while dotted arrows point to the syncytiotrophoblast labeling. (D) A western blot of human and mouse tissues revealed by an anti-ZFAT antibody. PBL stands for peripheral blood leukocytes whereas JEG-3 is a human choriocarcinoma cell line commonly used as a model of trophoblast.

Figure 6. Cloning and sequencing of PCR fragments obtained from bisulfite-treated placental gDNA in the promoter CpG island of the LIN28B gene. Black and white circles represent methylated and unmethylated cytosines respectively over the 32 CpG dinucleotides under study. SNPs are present within this fragment and allow the study of the allelic segregation and parental transmission.