Expression of DLK1 and MEG3 genes in porcine tissues during postnatal development

Abstract

The Drosophila-like homolog 1 (DLK1), a transmembrane signal protein similar to other members of the Notch/Delta/Serrate family, regulates the differentiation process in many types of mammalian cells. Callipyge sheep and DLK1 knockout mice are excellent examples of a fundamental role of the gene encoding DLK1 in muscle growth and fat deposition. DLK1 is located within co-regulated imprinted clusters (the DLK1/DIO3 domain), along with other imprinted genes. Some of these, e.g. the RNA coding MEG3 gene, presumedly interfere with DLK1 transcription. The aim of our study was to analyze DLK1 and MEG3 gene expression in porcine tissues (muscle, liver, kidney, heart, brain stem) during postnatal development. The highest expression of both DLK1 and MEG3 variant 1 (MEG3 var.1) was observed in the brain-stem and muscles, whereas that of MEG3 variant 2 (MEG3var.2) was the most abundant in muscles and the heart. During development (between 60 and 210 days of age) expression of analyzed genes was down-regulated in all the tissues. An exception was the brain- stem, where there was no significant change in MEG3 (both variants) mRNA level, and relatively little decline (2-fold) in that of DLK1 transcription. This may indicate a distinct function of the DLK1 gene in the brain-stem, when compared with other tissues.

Delayed muscle development in small pig fetuses around birth cannot be rectified by maternal early feed restriction and subsequent overfeeding during gestation

“…Indeed, the LM muscle of small fetuses at day 110 of gestation exhibited the highest expression of DLK1, a gene regulating differentiation of several cell types. This gene, which is highly expressed in embryonic muscle, is sharply down-regulated during postnatal development in porcine muscles (Oczkowicz et al, 2010) and almost completely abolished in human and mouse adult muscle (Andersen et al, 2008). Altogether time-related decrease in DLK1 expression level seems to be a mandatory step for normal myogenesis (White et al, 2008).…”

The long and short of non-coding RNAs during post-natal growth and differentiation of skeletal muscles: Focus on lncRNA and miRNAs

“…Meg3 has previously been examined during post-natal muscle development in pigs where it showed, as in mice, a relatively high expression after birth, followed by a rapid decrease (albeit at a later stage of growth) between day 90 and day 120 post-natally (Oczkowicz et al, 2010). In mice, the post-natal down-regulation of Meg3 between 2 days and 2 weeks might reflect the transition from growth of myofibres through hyperplasia of myonuclei to predominantly hypertrophy of myofibres during this time, and the progressively reduced requirement for this tumour suppressor lncRNA .…”

Delta-like 1 homolog in Capra hircus: molecular characteristics, expression pattern and phylogeny

“…Dlk1 is also involved in certain cancers [8], wound repair [9], obesity [10], and several signaling pathways [11][12][13][14]. The expression of Dlk1, which decreases gradually in postnatal porcine tissues, is more abundant in fetal than postnatal pigs [15,16]. Dlk1 protein, also known as Pref-1, SCP-1, FA-1, Zog, and pG2 [17], is a transmembrane and secreted protein.…”