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ABSTRACT: Six1 protein belongs to the Six homeoproteins family, exposing typical domain structure. Although the functions of Six1 have been drawn much attention, the roles of its individual domains are not completely elucidated. Here, we first detected the expression patterns of myogenin, MyoD, Myf5, and Six1 genes using real-time PCR in differentiating C2C12 cells cultured in differentiation medium for 2 or 6 days. The results showed that Six1 gene had the similar expression pattern with myogenin, MyoD, and Myf5 genes, which suggests that it may affect the myogenic differentiation. In order to evaluate the role of distinct domains of Six1 protein in subcellular localization, we constructed a series of truncated vectors tagged with green fluorescent proteins expressing various regions of porcine Six1 protein for subcellular localization analysis. Fluorescence confocal microscopy analysis showed that the different regions of Six1 protein displayed discrete distributions throughout the nucleus and the cytoplasm. The full-length CDS was exclusively localized in the nucleus and the individual HD domain was preferentially distributed to the nucleus both in C2C12 cells and in PK cells. However, the SD domain was diffusely distributed to the cytoplasm and the nucleus, and the localization of SD domain was biased to cytoplasm in C2C12 cells. Taken together, we conclude that the HD domain is important for the nuclear localization of porcine Six1 protein.
Molecular Biology Reports 06/2012; · 2.93 Impact Factor
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ABSTRACT: The temporal and spatial distribution of the genus Bacillus and Clostridium histolyticum group in swine manure composting was determined by fluorescent in situ hybridization using fluorescently labeled 16S rRNA-targeted oligonucleotide probes LGC353b and Chis150, respectively. The temporal distribution of total bacteria, Bacillus and C. histolyticum, detected in each layer of the composting pile was noticeable in that the number of them detected at the high-temperature stage was higher than that of the cooling stage. The number detected at the cooling stage was higher than that of the temperature-rising stage. The number of the total bacteria distributed in three locations achieved balance at the stage of cooling. The spatial distribution of the genus Bacillus cells was that the number and the relative abundance of Bacillus cells detected in the middle layer of composting pile were the lowest at each stage of composting. However, the minimum value of the relative abundance exceeded 8%. Compared with Bacillus spp., the C. histolyticum group displayed higher relative abundance in the same layer at different stages of composting except in the top layer at the stage of high temperature. However, the characteristic of the spatial distribution was not noticeable. The detected limits of the genus Bacillus and C. histolyticum group were both found to be the high cell density of 10(6) cells g(-1) (wet weight). These results indicated that the genus Bacillus and C. histolyticum group were the predominant bacteria in the swine manure composting process and may play important role in this complex environment.
Applied Microbiology and Biotechnology 09/2011; 93(6):2625-32. · 3.42 Impact Factor
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ABSTRACT: In order to obtain the diversity and temporal-spatial distribution of Bacillus community during the swine manure composting, we utilized traditional culture methods and the modern molecular biology techniques of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and -denaturing gradient gel electrophoresis (PCR-DGGE). Bacillus species were firstly isolated from the composting. Based on temperature changes, the temporal-spatial characteristics of total culturable Bacillus were remarkable that the number of the culturable Bacillus detected at the high-temperature stage was the highest in each layer of the pile and that detected in the middle layer was the lowest at each stage of composting respectively. The diversity of cultivated Bacillus species isolated from different composting stages was low. A total of 540 isolates were classified by the RFLP method and partial 16S rDNA sequences. They affiliated to eight species including Bacillus subtilis, Bacillus cereus, Bacillus thuringiensis, Bacillus anthracis, Bacillus megaterium, Bacillus licheniformis, Bacillus pumilus, and Bacillus circulans. The predominant species was B. subtilis, and the diversity of culturable Bacillus isolated in the middle-level samples at temperature rising and cooling stages was the highest. The DGGE profile and clone library analysis revealed that the temporal-spatial distribution of Bacillus community was not obvious, species belonging to the Bacillus were dominant (67%) with unculturable bacteria and B. cereus was the second major culturable Bacillus species. This study indicated that a combination of culture and culture-independent approaches could be very useful for monitoring the diversity and temporal-spatial distribution of Bacillus community during the composting process.
Applied Microbiology and Biotechnology 06/2011; 93(1):411-21. · 3.42 Impact Factor
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ABSTRACT: Six1 belongs to the Six gene family that includes six members in mammals (from Six1 to Six6). It has been demonstrated that Six1 homeodomain transcription factor is implicated in myogenesis. However, the molecular characteristics of Six1 in pigs have not been reported. In this study, we isolated and characterized the porcine Six1 gene full-length cDNA, genomic DNA and proximal promoter sequence. Semi-quantitative RT-PCR results confirmed that porcine Six1 was highly expressed in skeletal muscle. Real-time quantitative PCR results showed that porcine Six1 was highly expressed in embryonic stage and no significant expression differences is observed between Meishan and Yorkshire pigs. Furthermore, Six1 expression was significantly different among different developmental stages in Yorkshire pigs and the expression trend was up-regulated from 3 days to 180 days, reaching its highest expression level at 180 days. In addition, the data of Six1 expression in different muscles demonstrated that Six1 was a fast-twitch muscle high expression gene. PCR-HindII-RFLP was established to detect a C/T mutation and an A/G mutation which were present in promoter and intron, respectively. Meanwhile, their associations with economic traits were assessed in Meishan × Yorkshire F2 reference family. The statistical results revealed that the two HindII polymorphisms of porcine Six1 had significant associations with several meat quality traits (P<0.05). Taken together, these studies suggest that porcine Six1 may play an important role in skeletal muscle growth and meat quality.
Molecular Biology Reports 11/2010; 38(4):2619-32. · 2.93 Impact Factor
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ABSTRACT: Ladybird-like genes were recently identified in mammals. The first member characterized, Lbx1, is expressed in developing skeletal muscle and the nervous system. However, little is known about the porcine Lbx1 gene. In the present study, we cloned and characterized Lbx1 from porcine muscle. RT-PCR analyses showed that Lbx1 was highly expressed in porcine skeletal muscle tissues. And we provide the first evidence that Lbx1 has a certain regulated expression pattern during the postnatal period of the porcine skeletal muscle development. Lbx1 gene expressed at higher levels in biceps femoris muscles compared with masseter, semitendinosus and longissimus dorsi muscles in Meishan pigs. Phylogenetic tree was constructed by aligning the amino acid sequences of different species. Moreover, single nucleotide polymorphism (SNP) scanning in the Lbx1 genomic fragment identified two mutations, g.752A>G and g.-1559C>G. Association analysis in our experimental pig populations showed that the mutation of g.752A>G was significantly associated with loin muscle area (P<0.05) and internal fat rate (P<0.05). Our results suggest that the Lbx1 gene might be a candidate gene of carcass traits and provide useful information for further studies on its roles in porcine skeletal muscle.
Molecular Biology Reports 11/2010; 38(6):3983-91. · 2.93 Impact Factor