The ZIC transcription factors are key mediators of embryonic development and ZIC3 is the gene most commonly associated with situs defects (heterotaxy) in humans. Half of patient ZIC3 mutations introduce a premature termination codon (PTC). In vivo, PTC-containing transcripts might be targeted for nonsense-mediated decay (NMD). NMD efficiency is known to vary greatly between transcripts, tissues and individuals and it is possible that differences in survival of PTC-containing transcripts partially explain the striking phenotypic variability that characterizes ZIC3-associated congenital defects. For example, the PTC-containing transcripts might encode a C-terminally truncated protein that retains partial function or that dominantly interferes with other ZIC family members. Here we describe the katun (Ka) mouse mutant, which harbours a mutation in the Zic3 gene that results in a PTC. At the time of axis formation there is no discernible decrease in this PTC-containing transcript in vivo, indicating that the mammalian Zic3 transcript is relatively insensitive to NMD, prompting the need to re-examine the molecular function of the truncated proteins predicted from human studies and to determine whether the N-terminal portion of ZIC3 possesses dominant-negative capabilities. A combination of in vitro studies and analysis of the Ka phenotype indicate that it is a null allele of Zic3 and that the N-terminal portion of ZIC3 does not encode a dominant-negative molecule. Heterotaxy in patients with PTC-containing ZIC3 transcripts probably arises due to loss of ZIC3 function alone.
Pubmed ID: 23471918 RIS Download
Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.
A statistical software which can be used for basic statistics, experimental design, sample size calculations, and analysis of linear mixed models, time series, and spatial analysis.
View all literature mentionsCell line HEK293T is a Transformed cell line with a species of origin Homo sapiens (Human)
View all literature mentionslaboratory mouse with name BALB/cAnNCrl from MGI.
View all literature mentionsMus musculus with name C57BL/6J from IMSR.
View all literature mentionslaboratory mouse with name C3H/HeH from MGI.
View all literature mentionsCell line NIH 3T3 is a Spontaneously immortalized cell line with a species of origin Mus musculus
View all literature mentionsCell line COS-7 is a Transformed cell line with a species of origin Chlorocebus aethiops (Green monkey)
View all literature mentions