• Animal cells and systems
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• v.9 no.3
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• pp.107-111
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• 2005

C. elegans DLK-1 has been reported to play an important role in synaptogenesis by shaping the structure of presynaptic terminal. In this study, we investigated the expression pattern and regulation of the dlk-1 gene in C. elegans. To determine the expression pattern, we made a dlk-1::gfp fusion construct, named pPDdg1, which consisted of -2.2 kb 5' upstream region, the first exon, the first intron, and a part of the second exon of the dlk-1 gene. By microinjecting this construct into the worm, we observed that the DLK-1::GFP was expressed mainly in neurons. We next examined the regulatory elements of gene expression by deletion analysis of pPDdg1. Removal of a large portion of the 5' upstream region (${\Delta}-361$ to -2246) of the gene had little effect on the expression pattern, whereas deletion of the first intron led to elimination of the DLK-1::GFP expression in most of the neurons. Our results suggest that the first intron of the C. elegans dlk-1 gene contains the regulatory element critical for gene expression.

• Clinical and Experimental Pediatrics
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• v.65 no.4
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• pp.172-181
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• 2022

Pubertal onset is known to result from reactivation of the hypothalamic-pituitary-gonadal (HPG) axis, which is controlled by complex interactions of genetic and nongenetic factors. Most cases of precocious puberty (PP) are diagnosed as central PP (CPP), defined as premature activation of the HPG axis. The cause of CPP in most girls is not identifiable and, thus, referred to as idiopathic CPP (ICPP), whereas boys are more likely to have an organic lesion in the brain. ICPP has a genetic background, as supported by studies showing that maternal age at menarche is associated with pubertal timing in their offspring. A gain of expression in the kisspeptin gene (KISS1), gain-of-function mutation in the kisspeptin receptor gene (KISS1R), loss-of-function mutation in makorin ring finger protein 3 (MKRN3), and loss-of-function mutations in the delta-like homolog 1 gene (DLK1) have been associated with ICPP. Other genes, such as gamma-aminobutyric acid receptor subunit alpha-1 (GABRA1), lin-28 homolog B (LIN28B), neuropeptide Y (NPYR), tachykinin 3 (TAC3), and tachykinin receptor 3 (TACR3), have been implicated in the progression of ICPP, although their relationships require elucidation. Environmental and socioeconomic factors may also be correlated with ICPP. In the progression of CPP, epigenetic factors such as DNA methylation, histone posttranslational modifications, and non-coding ribonucleic acids may mediate the relationship between genetic and environmental factors. CPP is correlated with short- and long-term adverse health outcomes, which forms the rationale for research focusing on understanding its genetic and nongenetic factors.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.6
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• pp.693-699
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• 2010

Imprinted genes are essential for fetal development, growth regulation, and postnatal behavior. However, little is known about imprinted genes in livestock. We hypothesized that certain putatively imprinted genes affected normal peri-implantation development such as embryo elongation, initial placental development, and preparation of implantation. The objective of the present study was to investigate the mRNA expression patterns of several putatively imprinted genes during the porcine peri-implantation stages from day 6 to day 21 of gestation. Imprinted genes were selected both maternally (Dlk1, IGF2, Ndn, and Sgce) and paternally (IGF2r, H19, Gnas and Xist). Here, we report that the maternally imprinted gene IGF2 was expressed from day 6 (Blastocyst stage), but Dlk1, Ndn, and Sgce were not expressed in this stage. These genes were first expressed between days 12 and day 14. All the maternally imprinted genes studied showed significantly high expression patterns from day 18 of embryo development. In contrast, paternally imprinted genes IGF2r, H19, Gnas, and Xist were first expressed from day 6 of embryo development (BL). Our data demonstrated that the expression of H19 and Gnas genes was significantly increased from day 14 of the embryo developmental stage, while IGF2r and Xist only showed high expression after day 21. This study is the first to show that the putatively imprinted genes were stage-specific during porcine embryonic development. These results demonstrate that the genes studied may exert important effects on embryo implantation and fetal development.

• Journal of Embryo Transfer
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• v.25 no.2
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• pp.127-131
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• 2010

The objective of this study was to determine the mRNA expression patterns of several putative imprinted genes in in vivo and in vitro fertilized, parthenogenetic, and cloned porcine preimplantation embryos. Both maternally (Dlk1, IGF2, Peg1/Mest and Ndn) and paternally (IGF2r, H19 and Xist) imprinted genes were selected. We have used reverse transcription polymerase chain reaction (RT-PCR) to investigate gene expression patterns in the porcine embryos. IGF2 transcripts were detected in the most of embryos. In nuclear transfer (NT), Peg1/MEST transcripts showed fluctuating pattern. Dlk1 was only expressed partially from the morula and blastocyst stage of NT embryos. Ndn gene expression was started somewhat early for in vivo embryos. However, the expressions of maternally imprinted genes were similar in all types of blastocysts (NT, in vivo and in vitro fertilized, and parthenogenetic embryos). The IGF2R gene expression level was somewhat irregular and varied among samples. However, for the majority samples of all types of embryos, IGF2R expression was diminished after one- to two-cell stages and reappeared at the morulae or blastocyst stage embryos. H19 gene was only expressed early in parthenogenetic and in vivo embryos. For NT embryos, H19 was only expressed in blastocysts. Xist expression was detected in all blastocysts with the earliest being in vivo 8-cell stage embryos and the last one being NT blastocysts. These putative imprinted genes appeared to have stage specific expression patterns with a fluctuating pattern for some genes (Peg/Mest, IGF2r, H19). These results suggest that stage specific presence of imprinted genes can affect the embryo implantation and fetal development.

• Development and Reproduction
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• v.23 no.3
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• pp.213-221
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• 2019

The epididymal fat of mouse is a part of visceral fat deposit and is divided into the distal or proximal part based on its histochemical characteristics. Even though the formation of the epididymal fat pad begins before the birth, a detailed adipogenic procedure of the epididymal fat has not been revealed. The epididymal fat pad becomes enlarged and expended with age, and expressional changes of numerous genes are associated with the maturation of fat tissues. In the present research, expressional patterns of adipose tissue-related genes in the distal epididymal fat of mouse at 2, 5, 8, and 12 months of postnatal age were determined by a quantitative real-time polymerase chain reaction (PCR) analysis. The lowest transcript levels of fatty acid binding protein 4 (Fabp4), lipoprotein lipase (Lpl), delta like non-canonical Notch ligand 1 (Dlk1), peroxisome proliferator-activated receptor gamma (Pparg), leptin (Lep), adiponectin (Adipoq), and resistin (Retn) were detected at 2 months of age, except fatty acid synthase (Fasn) showing the lowest level at 5 months of age. Even though expression of Lep and Fabp4 were gradually increased until 12 months of age, significant increases of Pparg and Adipoq transcript levels were continued until 8 months of age. The transcript levels of Lpl, Rent, Dlk1, and Fasn were significantly increased at 8 months of age, compared with those at 2 months of age. The current findings suggest that the expansion of the distal epididymal fat of mouse during postnatal period would be companied with differential expression of various adipocyte-associated molecules.

• Development and Reproduction
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• v.23 no.4
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• pp.313-322
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• 2019

The epididymal fat pad is a male gonadal adipocyte tissue and is histochemically separated into distal and proximal parts. The development of epididymal fat during postnatal period has not been examined in detail. A previous research showed that expression of adipocyte-associated molecules in the distal epididymal fat of mouse is generally increased as postnatally aged. In the present study, expressional patterns of same adipocyte-associated molecules in the mouse proximal epididymal fat at 2, 5, 8, and 12 months of age were studied by quantitative real-time PCR analysis and were compared with those in the distal epididymal fat. The expressional levels of peroxisome proliferator-activated receptor gamma (Pparg), lipoprotein lipase (Lpl), and fatty acid synthase (Fasn) at 5 months of age were significantly lower than those at 2 months of age, while transcript level of leptin (Lep) at 5 months was higher than that at 2 months of age. The transcript levels of all molecules at 8 months of age were significantly increased, compared with those at 2 and 5 months of age. At 12 months of age, expression of delta like non-canonical Notch ligand 1 (Dlk1) was further significantly increased, while there was no change on the transcript level of Pparg and significant decreases of Fabp4, Retn, Lpl, Lep, Fasn, and adiponectin (Adipoq) transcript levels. The current findings show that expressional patterns of molecules associated with adipocyte in the proximal epididymal fat is somewhat different with those of the distal epididymal fat, suggesting the existence of regional variance in the epididymal fat.