International Mammalian Genome Society

The 16th International Mouse Genome Conference (2002)

Plenary Presentations * Oral Presentations *
Poster Presentations: Complex Genetics and Disease Modifiers * Developmental Genetics * Functional Genomics * Gene Discovery * Genetic Manipulations to Alter Gene Function * Mouse Models: Human Disease and Pharmacogenetics * Sequence Annotation and Comparative Analysis of Genomes *
Attendees * Sponsors * Table of Contents * Photographs * Awards

POSTER 42 - NOVEL TRANSCRIPTS WITHIN THE Gnas IMPRINTING CLUSTER

R Holmes
MRC Harwell

2) Wells C, 3) Monk D, 1) Williamson C, 1) Peters J
1) MRC Harwell, 2) University of QLD, 3) Imperial College

The Gnas cluster on mouse distal Chr 2 produces a number of oppositely imprinted and alternatively spliced transcripts, namely Nesp, Gnasxl and exon 1A from the sense strand and Nespas from the antisense strand. To determine the full extent of the cluster we have analysed the imprinting status of genes immediately flanking Gnas; these comprise Rabb22a, Vapb, Stx16 and Npepl1, which are proximal to Gnas, and Th1, Tubb1 and Edn3, which lie distal to Gnas. All were biallelically expressed indicating that the imprinting domain on distal Chr 2 maybe as small as 65kb, the size of the Gnas cluster. To identify novel transcripts within the imprinted cluster we have analysed the imprinting status of FANTOM2 cDNAs and new ESTs. Ten new imprinted transcripts have been detected. Five new maternal transcripts have been identified between Nesp and Gnasxl and upstream of exon 1A and which probably represent alternatively spliced forms of Nesp. Further investigations show that one of these is expressed tissue specifically in the pituitary in 17.5dpc embryos. Of the five paternally expressed transcripts two were antisense transcripts and three were sense. The antisense transcripts extend Nespas by 16kb upstream of Nesp. Of the sense transcripts one encompasses and extends the Gnasxl exon downstream and the other two include exon 1A and downstream sequence. Further investigations are underway to elucidate the roles of these transcripts.