Integrated transcriptome analysis reveals roles of long non-coding RNAs (lncRNAs) in caprine skeletal muscle mass and meat quality.

Long non-coding RNAs (lncRNAs) play important roles in the growth and development of skeletal muscle. However, there is limited information on goats. In this study, expression profiles of lncRNAs in Longissimus dorsi muscle from Liaoning cashmere (LC) goats and Ziwuling black (ZB) goats with divergent meat yield and meat quality were compared using RNA-sequencing. Based on our previous microRNA (miRNA) and mRNA profiles obtained from the same tissues, the target genes and binding miRNAs of differentially expressed lncRNAs were obtained. Subsequently, lncRNA-mRNA interaction networks and a ceRNA network of lncRNA-miRNA-mRNA were constructed. A total of 136 differentially expressed lncRNAs were identified between the two breeds. Fifteen cis target genes and 143 trans target genes were found for differentially expressed lncRNAs, and they were enriched in muscle contraction, muscle system process, muscle cell differentiation, and p53 signaling pathway. A total of 69 lncRNA-trans target gene pairs were constructed, with close relationship with muscle development, intramuscular fat deposition, and meat tenderness. A total of 16 lncRNA-miRNA-mRNA ceRNA pairs were identified, of which some reportedly associated with skeletal muscle development and fat deposition were found. The study will provide an improved understanding of the roles of lncRNAs in caprine meat yield and meat quality.

Identification and characterization of circular RNAs in Longissimus dorsi muscle tissue from two goat breeds using RNA-Seq.

Circular RNAs (circRNAs) are a class of non-coding RNA that play crucial roles in the growth and development of skeletal muscle. However, little is known about the role of circRNAs in caprine skeletal muscle. In this study, the size of muscle fiber and the expression profiles of circRNAs were compared in Longissimus dorsi muscle of Liaoning cashmere (LC) goats and Ziwuling black (ZB) goats with significant phenotypic differences in meat production performance, using hematoxylin and eosin staining and RNA-Seq, respectively. The size of muscle fiber in LC goats was larger than those in ZB goats (P < 0.05). A total of 10,875 circRNAs were identified and 214 of these were differentially expressed between the two caprine breeds. The parent genes of differentially expressed circRNAs were mainly enriched in connective tissue development, Rap1, cGMP-PKG, cAMP and Ras signaling pathway. In conclusion, circRNAs may play important roles in skeletal mass, meat production performance and meat quality traits in goats. The results provide an improved understanding of the functions of circRNAs in skeletal muscle development of goats.

Metabolome and transcriptome analysis of terpene synthase genes and their putative role in floral aroma production in Litchi chinensis.

Volatile organic compounds (VOCs) are essential traits of flowers since they attract pollinators, aid in seed distribution, protect the plant from internal and external stimuli, and are involved in plant-plant and plant-environment interactions. Apart from their role in plants, VOCs are used in pharmaceuticals, fragrances, cosmetics, and flavorings. Litchi (Litchi chinensis Sonn.) is a popular fruit due to its enticing red appearance, exotic taste, and high nutritional qualities. Litchi flowers bloom as inflorescences primarily on the shoot terminals. There are three distinct flower types, two male and one female, all of which are produced on the same panicle and rely on insect pollination. Herein, we used a comprehensive metabolomic approach to examine the volatile profile of litchi fruit (green pericarp, yellow pericarp, and red pericarp) as well as male and female flowers (bud stage, half open and full bloom). From a quantitative examination of the volatiles in L. chinensis, a total of 19, 22, and 21 VOCs were discovered from female flowers, male flowers, and fruits, with the majority of them belonging to sesquiterpenes. Multivariate analysis revealed that the volatile profiles of fruits differ from those of male and female flowers. Three VOCs were unique to male flowers and ten to the fruit, while eight VOCs were shared by both male and female flowers and eleven by both male and female flowers and the fruit. Furthermore, for the first time, we identified and comprehensively studied the TERPENE SYNTHASE genes (TPS) using the litchi genome and transcriptome database, which revealed 38 TPS genes unevenly distributed across the 15 chromosomes. A phylogenetic study showed that LcTPS were grouped into TPS-b, TPS-c, TPS-e, TPS-f, and TPS-g subfamilies, with TPS-b having the most genes. The conserved motifs (RRX8 W, NSE/DTE, and DDXX D) were studied in LcTPSs, and significant variation between subfamilies was discovered. Furthermore, after integrating the metabolome and transcriptome datasets, several VOCs were shown to be development-specific and highly linked with distinct LcTPS genes, making them promising biomarkers. Interestingly, LcTPS17/20/23/24/31 were associated with monoterpene edges, while the rest were connected to sesquiterpene edges, indicating their probable participation in the aroma biosynthesis mechanism of certain compounds.

Small RNA deep sequencing reveals the expressions of microRNAs in ovine mammary gland development at peak-lactation and during the non-lactating period.

MicroRNAs (miRNAs) are small non-coding RNAs that are involved in mammary gland development and lactation in livestock. Little is known about the roles of miRNAs in ovine mammary gland development, hence in this study the expression profiles of miRNAs of the mammary gland tissues of ewes at peak-lactation and during the non-lactating period were investigated using RNA sequencing. A total of 147 mature miRNAs were expressed in the two periods. Compared with peak-lactation, eight miRNAs in the non-lactating ewe mammary gland were significantly up-regulated, whereas fifteen miRNAs were down-regulated. A KEGG analysis revealed that the target genes of the up-regulated miRNAs were significantly enriched in lysosome, Wnt and MAPK signaling pathways, while the target genes of down-regulated miRNAs were significantly enriched in the PI3K-Akt signaling pathway, protein processing in endoplasmic reticulum and axon guidance. These results suggest that further study of the differentially expressed miRNAs could provide a better understanding of the molecular mechanisms of mammary development and lactation in sheep.

MicroRNA-381 Regulates Proliferation and Differentiation of Caprine Skeletal Muscle Satellite Cells by Targeting PTEN and JAG2.

In our previous study, microRNA (miR)-381 was found to be the most down-regulated miRNA in skeletal muscle of Liaoning cashmere goats with higher skeletal muscle mass, but the molecular mechanism involved remains unclear. In this study, primary caprine skeletal muscle satellite cells (SMSCs) were isolated and identified. We investigated the effect of miR-381 on the viability, proliferation and differentiation of caprine SMSCs, and the target relationships of miR-381 with jagged canonical Notch ligand 2 (JAG2) and phosphatase and tensin homolog (PTEN). Cells isolated were positive for SMSC-specific marker protein Pax7. This suggests that purified SMSCs were obtained. The expression level of miR-381 achieved a peak value on day 4 after SMSC differentiation, and miR-381 also significantly increased the expression levels of myogenic differentiation marker genes: myosin heavy chain (MyHC), myogenin (MyoG) and myocyte enhancer factor 2C (MEF2C) in differentiated SMSCs, the area of MyHC-positive myotubes and the myogenic index. These findings suggest that miR-381 promoted myogenic differentiation of caprine SMSCs. The CCK8 assay and EDU staining analysis showed that miR-381 mimic both inhibited the viability of SMSCs and decreased the percentage of EDU-labeled positive SMSCs. In contrast, miR-381 inhibitor had the opposite effect with miR-381 mimic. A dual luciferase reporter assay verified that miR-381 can target JAG2 and PTEN by binding to the 3'-untranslated regions (3'-UTR) of the genes. The transfection of miR-381 mimic into caprine SMSCs resulted in decreases in expression levels of JAG2 and PTEN, while miR-381 inhibitor increased the two target genes in expression. This is the first study to reveal the biological mechanisms by which miR-381 regulates caprine SMSC activities.

Identification and characterization of circular RNAs in mammary gland tissue from sheep at peak lactation and during the nonlactating period.

Circular RNAs are a class of noncoding RNA with a widespread occurrence in eukaryote tissues, and with some having been demonstrated to have clear biological function. In sheep, little is known about the role of circular RNAs in mammary gland tissue, and therefore an RNA sequencing approach was used to compare mammary gland tissue expression of circular RNAs in 9 Small Tail Han sheep at peak lactation, and subsequently when they were not lactating. These 9 sheep had their RNA pooled for analysis into 3 libraries from peak lactation and 3 from the nonlactating period. A total of 3,278 and 1,756 circular RNAs were identified in the peak lactation and nonlactating mammary gland tissues, respectively, and the expression and identity of 9 of them was confirmed using reverse transcriptase-polymerase chain reaction analysis and DNA sequencing. The type, chromosomal location and length of the circular RNAs identified were ascertained. Forty upregulated and one downregulated circular RNAs were characterized in the mammary gland tissue at peak lactation compared with the nonlactating mammary gland tissue. Gene ontology enrichment analysis revealed that the parental genes of these differentially expressed circular RNAs were related to molecular function, binding, protein binding, ATP binding, and ion binding. Five differentially expression circular RNAs were selected for further analysis to predict their target microRNAs, and some microRNAs reportedly associated with the development of the mammary gland were found in the constructed circular RNA-microRNA network. This study reveals the expression profiles and characterization of circular RNAs at 2 key stages of mammary gland activity, thereby providing an improved understanding of the roles of circular RNAs in the mammary gland of sheep.

Metabolomics Analysis of Litchi Leaves during Floral Induction Reveals Metabolic Improvement by Stem Girdling.

Prolonged exposure to cold temperatures often results in a relatively low flowering rate in litchi (Litchi chinensis Sonn.) trees with younger leaves. This study aimed to verify the impact of stem girdling on litchi flowering by identifying and characterizing the induced metabolic changes. After a 60 day exposure to cold treatment at 15 °C/10 °C (12 h/12 h), the flowering rate of the girdled trees was 100%, while that of the non-girdled trees was 20%, indicating that girdling improved litchi flowering at its turning stage. The metabolic profiles of litchi leaves with and without stem girdling during floral induction were compared and 505 metabolites potentially associated with litchi flowering were detected. Most metabolites were involved in the metabolism of starch and sucrose, fatty acid, and phenylpyruvic acid. The metabolic pathways concerned with the biosynthesis of epinephrine, sucrose, and d-maltose were induced in leaves after girdling treatment. The level of galactitol, phenylpyruvic acid, acetyl-CoA, linoleic acid, alpha-linolenic acid, and 13-HPOT biosynthesis remained stable in the leaves from girdled trees but changed drastically in the leaves from non-girdled trees. In addition, 379 metabolites concerning flowering rate were characterized. Metabolism pathways of starch and sucrose, galactose, and linoleic acid are of great significance to the flowering of litchi. Linoleic acid exhibited the most significant variations between girdled trees and non-girdled trees with fold changes of up to 13.62. These results contribute to understanding the biological mechanism of litchi floral induction and the metabolic changes after stem girdling.

Transcriptome profiling of litchi leaves in response to low temperature reveals candidate regulatory genes and key metabolic events during floral induction.

BACKGROUND: Litchi (Litchi chinensis Sonn.) is an economically important evergreen fruit tree widely cultivated in subtropical areas. Low temperature is absolutely required for floral induction of litchi, but its molecular mechanism is not fully understood. Leaves of litchi played a key role during floral induction and could be the site of low temperature perception. Therefore, leaves were treated under different temperature (15 °C/25 °C), and high-throughput RNA sequencing (RNA-Seq) performed with leaf samples for the de novo assembly and digital gene expression (DGE) profiling analyses to investigate low temperature-induced gene expression changes. RESULTS: 83,107 RNA-Seq unigenes were de novo assembled with a mean length of 1221 bp and approximately 61% of these unigenes (50,345) were annotated against public protein databases. Differentially-expressed genes (DEGs) under low temperature treatment in comparison with the control group were the main focus of our study. Hierarchical clustering analysis arranged 2755 DEGs into eight groups with three significant expression clusters (p-value ≤ 0.05) during floral induction. With the increasing contents of sugars and starch, the expression of genes involved in metabolism of sugars increased dramatically after low temperature induction. One FT gene (Unigene0025396, LcFT1) which produces a protein called 'florigen' was also detected among DEGs of litchi. LcFT1 exhibited an apparent specific tissue and its expression was highly increased after low temperature induction, GUS staining results also showed GUS activity driven by LcFT1 gene promoter can be induced by low temperature, which indicated LcFT1 probably played a pivotal role in the floral induction of litchi under low temperature. CONCLUSIONS: Our study provides a global survey of transcriptomes to better understand the molecular mechanisms underlying changes of leaves in response to low temperature induction in litchi. The analyses of transcriptome profiles and physiological indicators will help us study the complicated metabolism of floral induction in the subtropic evergreen plants.

A 13-lipoxygenase, TomloxC, is essential for synthesis of C5 flavour volatiles in tomato.

C5 volatile compounds, derived from fatty acids, are among the most important contributors to consumer liking of fresh tomatoes. Despite their important roles in flavour, the genes responsible for C5 volatile synthesis have yet to be identified. This work shows that their synthesis is catalysed in part by a 13-lipoxygenase (LOX), TomloxC, the same enzyme responsible for synthesis of C6 volatiles. C5 synthesis is independent of hydroperoxide lyase (HPL); moreover, HPL knockdown significantly increased C5 volatile synthesis. This LOX-dependent, HPL-independent pathway functions in both fruits and leaves. Synthesis of C5 volatiles increases in leaves following mechanical wounding but does not increase in response to infection with Xanthomonas campestris pv. vesicatoria. Large reductions in C5 and C6 volatiles in antisense TomloxC knockdown plants were observed but those reductions did not alter the development of disease symptoms, indicating that these volatiles do not have an important defensive function against this bacterial pathogen.

Transcriptomic analysis of floral initiation in litchi (Litchi chinensis Sonn.) based on de novo RNA sequencing.

KEY MESSAGE: Comparative transcriptome analysis of litchi ( Litchi chinensis Sonn.) buds at two developmental stages revealed multiple processes involving various phytohormones regulating floral initiation, and expression of numerous flowering-related genes. Floral initiation is a critical and complicated plant developmental process involving interactions of numerous endogenous and environmental factors, but little is known about the complex network regulating floral initiation in litchi (Litchi chinensis Sonn.). Illumina second-generation sequencing is an efficient method for obtaining massive transcriptional information resulting from phase changes in plant development. In this study, comparative transcriptomic analysis was performed with resting and emerging panicle stage buds, to gain further understanding of the molecular mechanisms involved in floral initiation in litchi. Abundance analysis identified 5,928 unigenes exhibiting at least twofold differences in expression between the two bud stages. Of these, 4,622 unigenes were up-regulated and 1,306 were down-regulated in panicle-emerging buds compared with resting buds. KEGG pathway enrichment analysis revealed that unigenes exhibiting differential expression were involved in the metabolism and signal transduction of various phytohormones. The expression levels of unigenes annotated as auxin, cytokinin, jasmonic acid, and salicylic acid biosynthesis were up-regulated, whereas those unigenes annotated as abscisic acid biosynthesis were down-regulated during floral initiation. In addition, 188 unigenes exhibiting sequence similarities to known flowering-related genes from other plants were differentially expressed during floral initiation. Thirteen genes were selected for confirmation of expression levels using quantitative-PCR. Our results provide abundant sequence resources for studying mechanisms underlying floral initiation in litchi and establish a platform for further studies of litchi and other evergreen fruit trees.

Bagging treatment influences production of C6 aldehydes and biosynthesis-related gene expression in peach fruit skin.

Bagging is a useful method to improve fruit quality by altering its exposure to light, whereas its effect on fruit volatiles production is inconsistent, and the genes responsible for the observed changes remain unknown. In the present study, single-layer yellow paper bags were used to study the effects of bagging treatment on the formation of C6 aldehydes in peach fruit (Prunus persica L. Batsch, cv. Yulu) over two succeeding seasons. Higher concentrations of n-hexanal and (E)-2-hexenal, which are characteristic aroma volatiles of peach fruit, were induced by bagging treatment. After bagging treatment, peach fruit had significantly higher LOX and HPL enzyme activities, accompanying increased contents of C6 aldehydes. The gene expression data obtained through real-time PCR showed that no consistent significant differences in transcript levels of LOX genes were observed over the two seasons, but significantly up-regulated expression was found for PpHPL1 after bagging treatment In addition, bagging-treated fruit produced more (E)-2-hexenal and had higher expression levels of PpHPL1 during postharvest ripening at room temperature. The regulatory role of the LOX-HPL pathway on the biosynthesis of n-hexanal and (E)-2-hexenal in response to bagging treatment during peach fruit development is discussed in the text.

Identification and screening of circular RNAs during adipogenic differentiation of ovine preadipocyte by RNA-seq.

Circular RNAs (circRNAs) are a class of non-coding RNAs that play important roles in preadipocyte differentiation and adipogenesis. However, little is known about genome-wide identification, expression profile, and function of circRNAs in sheep. To investigate the role of circRNAs during ovine adipogenic differentiation, the subcutaneous adipose tissue of Tibetan rams was collected in June 2022. Subsequently, the preadipocytes were immediately isolated from collected adipose tissue and then induced to begin differentiation. The adipocytes samples cultured on days 0, 2, and 8 of preadipocytes differentiation were used to perform RNA sequencing (RNA-seq) analysis to construct the expression profiles of circRNAs. Subsequently, the function of differentially expressed circRNAs was investigated by performing the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of their parent genes. Finally, a circRNAs-miRNAs-mRNAs network involved in adipogenic differentiation was been analyzed. As a result, a total of 6,449 candidate circRNAs were identified in ovine preadipocytes. Of these circRNAs identified, 63 candidate circRNAs were differentially expressed among the three differentiation stages and their parent genes were mainly enriched in acetyl-CoA metabolic process, positive regulation of lipid biosynthetic process, positive regulation of steroid biosynthetic process, and focal adhesion pathway (P < 0.05). Based on a circRNAs-miRNAs-mRNAs regulatory network constructed, circ_004977, circ_006132 and circ_003788 were found to function as competing endogenous RNAs (ceRNAs) to regulate ovine preadipocyte differentiation and lipid metabolism. The results provide an improved understanding of functions and molecular mechanisms of circRNAs underlying ovine adipogenesis in sheep.

The moderate fat deposition contributes to improve mutton quality, which is associated with the differentiation of preadipocytes. To investigate roles of circular RNAs (circRNAs) in preadipocyte differentiation, we identified circRNAs on days 0, 2, and 8 of preadipocytes differentiation and compared the expression profile of circRNAs at different adipogenic differentiation stages. A total of 6,449 candidate circRNAs were identified, among which 63 candidate circRNAs were differentially expressed among the three differentiation stages. The parent genes of differentially expressed circRNAs were enriched in several biological process and pathways related to lipid metabolism and synthesis. In addition, several circRNAs may regulate ovine preadipocyte differentiation by interacting with microRNAs (miRNAs). The results reveal the potential roles of circRNAs in adipogenic differentiation of sheep.

Rhein kills Actinobacillus pleuropneumoniae, reduces biofilm formation, and effectively treats bacterial lung infections in mice.

Background. Actinobacillus pleuropneumoniae, a member of the Pasteurellaceae family, is known for its highly infectious nature and is the primary causative agent of infectious pleuropneumonia in pigs. This disease poses a considerable threat to the global pig industry and leads to substantial economic losses due to reduced productivity, increased mortality rates, and the need for extensive veterinary care and treatment. Due to the emergence of multi-drug-resistant strains, Chinese herbal medicine is considered one of the best alternatives to antibiotics due to its unique mechanism of action and other properties. As a type of Chinese herbal medicine, Rhein has the advantages of a wide antibacterial spectrum and is less likely to develop drug resistance, which can perfectly solve the limitations of current antibacterial treatments.Methods. The killing effect of Rhein on A. pleuropneumoniae was detected by fluorescence quantification of differential expression changes of key genes, and scanning electron microscopy was used to observe the changes in A. pleuropneumoniae status after Rhein treatment. Establishing a mouse model to observe the treatment of Rhein after A. pleuropneumoniae infection.Results. Here, in this study, we found that Rhein had a good killing effect on A. pleuropneumoniae and that the MIC was 25 µg ml-1. After 3 h of action, Rhein (4×MIC) completely kills A. pleuropneumoniae and Rhein has good stability. In addition, the treatment with Rhein (1×MIC) significantly reduced the formation of bacterial biofilms. Therapeutic evaluation in a murine model showed that Rhein protects mice from A. pleuropneumoniae and relieves lung inflammation. Quantitative RT-PCR (Quantitative reverse transcription polymerase chain reaction is a molecular biology technique that combines both reverse transcription and polymerase chain reaction methods to quantitatively detect the amount of a specific RNA molecule) results showed that Rhein treatment significantly downregulated the expression of the IL-18 (Interleukin refers to a class of cytokines produced by white blood cells), TNF-α, p65 and p38 genes. Along with the downregulation of genes such as IL-18, it means that Rhein has an inhibitory effect on the expression of these genes, thereby reducing the activation of inflammatory cells and the production of inflammatory mediators. This helps reduce inflammation and protects tissue from further damage.Conclusions. This study reports the activity of Rhein against A. pleuropneumoniae and its mechanism, and reveals the ability of Rhein to treat A. pleuropneumoniae infection in mice, laying the foundation for the development of new drugs for bacterial infections.

Involvement of CBF in the fine-tuning of litchi flowering time and cold and drought stresses.

Litchi (Litchi chinensis) is an economically important fruit tree in southern China and is widely cultivated in subtropical regions. However, irregular flowering attributed to inadequate floral induction leads to a seriously fluctuating bearing. Litchi floral initiation is largely determined by cold temperatures, whereas the underlying molecular mechanisms have yet to be identified. In this study, we identified four CRT/DRE BINDING FACTORS (CBF) homologs in litchi, of which LcCBF1, LcCBF2 and LcCBF3 showed a decrease in response to the floral inductive cold. A similar expression pattern was observed for the MOTHER OF FT AND TFL1 homolog (LcMFT) in litchi. Furthermore, both LcCBF2 and LcCBF3 were found to bind to the promoter of LcMFT to activate its expression, as indicated by the analysis of yeast-one-hybrid (Y1H), electrophoretic mobility shift assays (EMSA), and dual luciferase complementation assays. Ectopic overexpression of LcCBF2 and LcCBF3 in Arabidopsis caused delayed flowering and increased freezing and drought tolerance, whereas overexpression of LcMFT in Arabidopsis had no significant effect on flowering time. Taken together, we identified LcCBF2 and LcCBF3 as upstream activators of LcMFT and proposed the contribution of the cold-responsive CBF to the fine-tuning of flowering time.

Postharvest temperature influences volatile lactone production via regulation of acyl-CoA oxidases in peach fruit.

The biosynthesis of volatile compounds in plants is affected by environmental conditions. Lactones are considered to be peach-like aroma volatiles; however, no enzymes or genes associated with their biosynthesis have been characterized. White-fleshed (cv. Hujingmilu) and yellow-fleshed (cv. Jinxiu) melting peach (Prunus persica L. Batsch) fruit were used as materials in two successive seasons and responses measured to four different temperature treatments. Five major lactones accumulated during postharvest peach fruit ripening at 20 °C. Peach fruit at 5 °C, which induces chilling injury (CI), had the lowest lactone content during subsequent shelf life after removal, while 0 °C and a low-temperature conditioning (LTC) treatment alleviated development of CI and maintained significantly higher lactone contents. Expression of PpACX1 and activity of acyl-CoA oxidase (ACX) with C16-CoA tended to increase during postharvest ripening both at 20 °C and during shelf life after removal from cold storage when no CI was developed. There was a positive correlation between ACX and lactones in peach fruit postharvest. Changes in lactone production in response to temperatures are suggested to be a consequence of altered expression of PpACX1 and long-chain ACX activity.

Effect of Nano-TiO2 Composite on the Fertilization and Fruit-Setting of Litchi.

Titanium dioxide nanoparticles (nTiO2) are widely used as fertilizers in agricultural production because they promote photosynthesis and strong adhesion. Low pollination and fertilization due to rainy weather during the litchi plant's flowering phase result in poor fruit quality and output. nTiO2 would affect litchi during the flowering and fruiting stages. This study considers how nTiO2 affects litchi's fruit quality and pollen viability during the flowering stage. The effects of nTiO2 treatment on pollen vigor, yield, and fruit quality were investigated. nTiO2 effectively improved the pollen germination rate and pollen tube length of litchi male flowers. The germination rate reached 22.31 ± 1.70%, and the pollen tube reached 237.66 µm in the 450 mg/L reagent-treated group. Spraying with 150 mg/L of nTiO2 increased the germination rate of pollen by 2.67% and 3.67% for two types of male flowers (M1 and M2) of anthesis, respectively. After nTiO2 spraying, the fruit set rates of 'Guiwei' and 'Nomici' were 46.68% and 30.33%, respectively, higher than those of the boric acid treatment group and the control group. The edibility rate, titration calculation, and vitamin C of nTiO2 treatment were significantly higher than those of the control. The nTiO2-treated litchi fruit was more vividly colored. Meanwhile, the adhesion of nTiO2 to leaves was effectively optimized by using ATP and BCS to form nTiO2 carriers and configuring nTiO2 complex reagents. These results set the foundation for future applications of titanium dioxide nanoparticles as fertilizers for agriculture and guide their application to flowers and fruits.

Characteristics and Expression of circ_003628 and Its Promoted Effect on Proliferation and Differentiation of Skeletal Muscle Satellite Cells in Goats.

In our previous a study, circ_003628 was one of the most highly expressed circular RNAs (circRNAs) in the Longissimus dorsi muscle of goats found by RNA-seq, suggesting that the circRNA may be important for caprine muscle growth and development. However, there have been no reports describing the molecular mechanisms by which circ_003628 regulates the activities of goat skeletal muscle satellite cells (SMSCs). In this study, reverse transcriptase-PCR (RT-PCR) and DNA sequencing were used to validate the authenticity of circ_003628, and its characteristics, expression profile and effect on goat SMSCs were also studied using real-time quantitative-PCR (RT-qPCR), EdU, CCK-8 and immunofluorescence assays. Circ_003628 is partially originated from 13 exons, 12 introns and 3'-untranslated regions (UTR) of caprine Myosin Heavy Chain 1 (MYH1), and 25 exons and 5' UTR of Myosin Heavy Chain 4 (MYH4), as well as intergenic sequences between the two genes. A total of 77.07% of circ_003628 were located in the nuclei of goat SMSCs, while 22.93% were expressed in the cytoplasm. The circRNAs were only expressed in triceps brachii, quadriceps femoris and longissimus dorsi muscle tissues in nine caprine tissues investigated, with the highest expression level in longissimus dorsi muscle. The expression level of circ_003628 gradually increased during differentiation periods of goat SMSCs and reached the maximum on day 6 after differentiation. The small interfering RNA of circ_003628 (named si-circ_003628) inhibited the viability and proliferation of goat SMSCs, and also decreased the expression of four cell proliferation marker genes: paired box 7 (Pax7), cyclin-dependent kinase 2 (CDK2), CDK4 and CyclinD1 in goat SMSCs. Transfection of si-circ_003628 significantly decreased the area of MyHC-labeled myotubes of goat SMSCs, as well as the expression levels of three differentiation marker genes: myosin heavy chain (MyHC), myogenin (MyoG), and myocyte enhancer factor 2C (MEF2C). These results suggest that circ_003628 promotes the viability, proliferation, and differentiation of goat SMSCs, and they also provide an improved understanding of the roles of circ_003628 in skeletal muscle growth and development in goats.

Force-Induced Synergetic Pigmentary and Structural Color Change of Liquid Crystalline Elastomer with Nanoparticle-Enhanced Mechanosensitivity.

The ability of some animals to rapidly change their colors can greatly improve their chances of escaping predators or hunting prey. A classic example is cephalopods, which can rapidly shift through a wide range of colors. This ability is based on the synergetic effect of the change of pigmentary and structural colors exhibited by their own two categories of color-changing cells: supernatant chromatophores offer various pigmentary colors and lower iridophores or leucophores reflect the different structural colors by adjusting their periodicities. Here, a mechanochromic liquid crystalline elastomer with force-induced synergetic pigmentary and structural color change, whose mechanosensitivity is enhanced by the stress-concentration induced by the doped nanoparticle, is presented. The materials have a large color-changing gamut and high mechanochromic sensitivity, which exhibit great potential in the field of mechanical detectors, sensors, and anti-counterfeiting materials.

Deep Small RNA Sequencing Reveals Important miRNAs Related to Muscle Development and Intramuscular Fat Deposition in Longissimus dorsi Muscle From Different Goat Breeds.

MicroRNAs (miRNAs) are a class of small non-coding RNAs that have been shown to play important post-transcriptional regulatory roles in the growth and development of skeletal muscle tissues. However, limited research into the effect of miRNAs on muscle development in goats has been reported. In this study, Liaoning cashmere (LC) goats and Ziwuling black (ZB) goats with significant phenotype difference in meat production performance were selected and the difference in Longissimus dorsi muscle tissue expression profile of miRNAs between the two goat breeds was then compared using small RNA sequencing. A total of 1,623 miRNAs were identified in Longissimus dorsi muscle tissues of the two goat breeds, including 410 known caprine miRNAs, 928 known species-conserved miRNAs and 285 novel miRNAs. Of these, 1,142 were co-expressed in both breeds, while 230 and 251 miRNAs were only expressed in LC and ZB goats, respectively. Compared with ZB goats, 24 up-regulated miRNAs and 135 miRNAs down-regulated were screened in LC goats. A miRNA-mRNA interaction network showed that the differentially expressed miRNAs would target important functional genes associated with muscle development and intramuscular fat deposition. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that the target genes of differentially expressed miRNAs were significantly enriched in Ras, Rap 1, FoxO, and Hippo signaling pathways. This study suggested that these differentially expressed miRNAs may be responsible for the phenotype differences in meat production performance between the two goat breeds, thereby providing an improved understanding of the roles of miRNAs in muscle tissue of goats.

Variation in caprine KRTAP1-3 and its association with cashmere fibre diameter.

Keratin-associated proteins (KAPs) are components of cashmere fibres. The gene encoding the KAP1-3 protein (KRTAP1-3) has been described in goats, but little is known about sequence variation in this gene and if it affects cashmere fibre traits. In this study, we used a polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) technique to screen for nucleotide sequence variation in caprine KRTAP1-3 in 327 Longdong cashmere goats, then analysed association between the genetic variation that was revealed and some cashmere fibre traits. Six PCR-SSCP patterns representing six different variant sequences of KRTAP1-3 (named A to F) were revealed. Among these variant sequences, seven single nucleotide polymorphisms (SNPs) were detected, with two of them being non-synonymous. Goats with genotype AC had higher mean fibre diameter (MFD) than those with genotype AB (P < 0.001), while goats with genotype AB had higher MFD than those with AA (P < 0.001). The presence of C (P < 0.001) and B (P = 0.006) in a genotype was associated with increased MFD, and together this suggests that variation in caprine KRTAP1-3 affects the key fibre trait of MFD.