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Is it genomic imprinting or preferential expression?
Author(s) -
Khatib Hasan
Publication year - 2007
Publication title -
bioessays
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.175
H-Index - 184
eISSN - 1521-1878
pISSN - 0265-9247
DOI - 10.1002/bies.20637
Subject(s) - genomic imprinting , imprinting (psychology) , gene , biology , allele , genetics , gene expression , dna methylation
Abstract Imprinted genes are monoallelically expressed in a parent‐of‐origin‐specific manner, but for many genes reported to be imprinted, the occurrence of preferential expression—where both alleles are expressed but one is expressed more strongly than the other in a parent‐of‐origin‐specific way—has been reported. This preferential expression found in genes described as imprinted has not been thoroughly addressed in genomic imprinting studies. To study this phenomenon, 50 genes, reported to be imprinted in the mouse, were chosen for investigation. Preferential expression was observed for 21 of 27 maternally expressed genes. However, only 5 of 23 paternally expressed genes showed preferential expression. Recently, it has been reported that a remarkable proportion of non‐imprinted genes show differential allelic expression. If there is overlap between non‐imprinted genes that are differentially expressed and imprinted genes that are preferentially expressed, we need to set new definitions of imprinted genes that, in turn, would probably lead to reassessments of the total number of imprinted genes in mammalian species. BioEssays 29:1022–1028, 2007. © 2007 Wiley Periodicals, Inc.