The Role of Introgression During the Radiation of Endemic Fishes Adapted to Living at Extreme Altitudes in the Tibetan Plateau.

Recent genomic analyses of evolutionary radiations suggest that ancient introgression may facilitate rapid diversification and adaptive radiation. The loach genus Triplophysa, a genus with most species endemic to Tibetan Plateau, shows ecological diversity and rapid evolution and represents a potential example of adaptive radiation linked to the uplift of the Tibetan Plateau. Here, we interrogate the complex evolutionary history of Triplophysa fishes through the analysis of whole-genome sequences. By reconstructing the phylogeny of Triplophysa, quantifying introgression across this clade, and simulating speciation and migration processes, we confirm that extensive gene flow events occurred across disparate Triplophysa species. Our results suggest that introgression plays a more substantial role than incomplete lineage sorting in underpinning phylogenetic discordance in Triplophysa. The results also indicate that genomic regions affected by ancient gene flow exhibit characteristics of lower recombination rates and nucleotide diversity and may associate with selection. Simulation analysis of Triplophysa tibetana suggests that the species may have been affected by the Gonghe Movement in the third uplift of the Tibetan Plateau, resulting in founder effects and a subsequent reduction in Ne.

Imbalance in lake variability but not embodying driving factors on the Qinghai-Tibetan Plateau calls on heterogeneous lake management.

Comprehensive regional remote analysis tends to neglect lakes in exorheic basins on the Qinghai-Tibetan Plateau (QTP), and a concurrent lack of discussions on whether there exist imbalanced explanations for the driving forces of both internal and external lakes is also present. We integrate multisourced lake datasets, high-resolution information, and available altimetry datasets to establish multiple mathematical models to meta-simulate lake volume changes, extend current lake variation datasets, and quantify the imbalance of variations and factors driving the water mass budget. The results showed that the primary cause of lake variations in QTP is net precipitation (57.75 ± 31.46%), followed by glacier runoff (33.53 ± 31.42%), and permafrost (8.34 ± 7.87%). Even though glacier runoff is currently considered as a weak factor of lake variation, heterogeneous results call for remaining attention in glacier-induced lake basins. Imbalance embodying in lake variability but not in contributions of driving factors, which calls for special lake management ways in different watersheds.

Fast Image Super-Resolution Using Particle Swarm Optimization-Based Convolutional Neural Networks.

Image super-resolution based on convolutional neural networks (CNN) is a hot topic in image processing. However, image super-resolution faces significant challenges in practical applications. Improving its performance on lightweight architectures is important for real-time super-resolution. In this paper, a joint algorithm consisting of modified particle swarm optimization (SMCPSO) and fast super-resolution convolutional neural networks (FSRCNN) is proposed. In addition, a mutation mechanism for particle swarm optimization (PSO) was obtained. Specifically, the SMCPSO algorithm was introduced to optimize the weights and bias of the CNNs, and the aggregation degree of the particles was adjusted adaptively by a mutation mechanism to ensure the global searching ability of the particles and the diversity of the population. The results showed that SMCPSO-FSRCNN achieved the most significant improvement, being about 4.84% better than the FSRCNN model, using the BSD100 data set at a scale factor of 2. In addition, a chest X-ray super-resolution images classification test experiment was conducted, and the experimental results demonstrated that the reconstruction ability of this model could improve the classification accuracy by 13.46%; in particular, the precision and recall rate of COVID-19 were improved by 45.3% and 6.92%, respectively.

Biofilm-Based Biocatalysis for Galactooligosaccharides Production by the Surface Display of ß-Galactosidase in Pichia pastoris.

Galactooligosaccharides (GOS) are one of the most important functional oligosaccharide prebiotics. The surface display of enzymes was considered one of the most excellent strategies to obtain these products. However, a rough industrial environment would affect the biocatalytic process. The catalytic process could be efficiently improved using biofilm-based fermentation with high resistance and activity. Therefore, the combination of the surface display of ß-galactosidase and biofilm formation in Pichia pastoris was constructed. The results showed that the catalytic conversion rate of GOS was up to 50.3% with the maximum enzyme activity of 5125 U/g by screening the anchorin, and the number of the continuous catalysis batches was up to 23 times. Thus, surface display based on biofilm-immobilized fermentation integrated catalysis and growth was a co-culture system, such that a dynamic equilibrium in the consolidated integrative process was achieved. This study provides the basis for developing biofilm-based surface display methods in P. pastoris during biochemical production processes.

Molecular cloning and tissue distribution of the leptin gene in gibel carp (Carassius auratus gibelio): Regulation by postprandial and long-term fasting treatment.

Leptin is a multifunctional hormone that serves as a feeding regulator in mammals. However, the effect of leptin on fish remains unclear. We sequenced the leptin gene from gibel carp (Carassius auratus gibelio) and designated it gLEP. The length of the gLEP cDNA sequence was 562 bp, including an open reading frame (ORF) of 516 bp. The ORF putatively encodes a peptide of 171 amino acids, including a signal peptide of 20 amino acids. gLEP shared low primary amino acid sequence homology with leptin genes in vertebrates, whereas three-dimensional (3D) structural modeling revealed strong identity with the structures in other vertebrates. gLEP mRNA was widely distributed in all of the tissue that we examined, with the highest levels of expression in the hepatopancreas. Hepatopancreas gLEP mRNA expression levels showed no changes following postprandial treatment. However, hepatopancreas gLEP mRNA expression levels greatly decreased (P < 0.05) after fasting but substantially increased (P < 0.05) after refeeding in the long-term fasting treatment. In summary, these results indicate that leptin expression could be influenced by the regulation of food intake. These results provide the initial step toward elucidating the appetite regulatory systems associated with leptin in gibel carp.

Characterization and evaluation of the tissue distribution of CRH, apelin, and GnRH2 reveal responses to feeding states in Schizothorax davidi.

Schizothorax davidi is a rare fish in Southwest China and is considered a promising species for aquaculture. Compared with other teleosts, little is known about the endocrine regulation of feeding in this species. In this study, we identified the CRH, apelin, and GnRH2 genes in S. davidi and assessed the effects of different energy statuses on CRH, apelin, and GnRH2 expression. Our results showed that the full-length cDNA sequences of CRH, apelin, and GnRH2 of S. davidi were 995, 905, and 669 bp long, respectively. Furthermore, CRH was mainly expressed in the hypothalamus, telencephalon, and myelencephalon; apelin was highly expressed in the spleen and heart; and GnRH2 mRNA was widely distributed in all examined tissues, with the highest level in the hypothalamus. Notably, the levels of CRH and GnRH2 increased in the hypothalamus at 1 h and 3 h post-feeding, while hypothalamic apelin levels decreased. Conversely, CRH and GnRH2 expression in the hypothalamus significantly decreased after fasting for 7 days and returned to the control levels after re-feeding for 3 or 5 days. In contrast, fasting increased apelin levels in the hypothalamus. Overall, this study suggests that CRH, apelin, and GnRH2 play critical roles in appetite regulation in S. davidi. These results provide an essential groundwork to elucidate the appetite regulatory systems in S. davidi as well as in other teleosts.

The Regional Impact of Ecological Restoration in the Arid Steppe on Dust Reduction over the Metropolitan Area in Northeastern China.

A massive ecological restoration program has been implemented in northern China with the aim of protecting the Beijing-Tianjin-Hebei metropolitan area of eastern China from dust events. However, some current studies have cast doubt on the efficacy of such ecological restoration projects, partly due to the constraint of available water in northern China, leading to poor survival rates of planted trees in semiarid regions (15%). In this study, using a logical framework combining statistical analysis, partial least-squares path model analysis, and a regional climate model (RegCM) simulation with multisource dust indicators, we found that there was a reduction of dust in northern China that was synchronous with the increase in vegetation growth after ecological restoration. In contrast to previous reports of a decrease in wind speed due to ecological restoration, this study found that the increase in vegetation had an insignificant impact on local wind speed (p = 0.30). Instead, ecological restoration mainly reduced the sand emission in steppe area by improving the soil conditions of the underlying surface, and hence contributed 15% of the reduction of dust events in the Beijing-Tianjin-Hebei metropolitan area through dust transmission (p = 0.002). The effect of ecological restoration in the northern steppe on dust reduction over the northeastern metropolitan area of China should not be overstated.

Effects of feeding status on nucb1 and nucb2A mRNA expression in the hypothalamus of Schizothorax davidi.

NUCB1 and NUCB2, two novel nucleobindins, have attracted extensive attention for their role in the appetite regulation in mammals. However, little is known about the appetite regulation of NUCB1 and NUCB2 in fish species. Therefore, we investigated the role of these peptides in the regulation of feeding in Schizothorax davidi (S. davidi). In this study, full-length cDNA sequences of nucb1 and nucb2A of S. davidi were obtained for the first time. Additionally, the tissue distribution and the effects of different energy status on nucb1 and nucb2A mRNAs abundance were assessed, showing that nucb1 and nucb2A are widely distributed in 18 detected tissues, with the highest expression in the cerebellum. The abundances of nucb1 and nucb2A increased in the hypothalamus at 1 h and 3 h post-feeding. Furthermore, fasting and re-feeding experiments showed that the expressions of nucb1 and nucb2A in hypothalamus significantly decreased after fasting for 7 days, and returned to the control level after re-feeding for 3 or 5 days. In conclusion, the present study suggests that both NUCB1 and NUCB2A are involved in the short-term and long-term appetite regulation, as an anorexigenic factor, in S. davidi. These results can provide a basis for further investigation into the appetite regulatory role of NUCB family in teleost.

Three forms of cocaine- and amphetamine-regulated transcript may be involved in food intake regulation in gibel carp (Carassius auratus gibelio).

In fish, as in mammals, several studies have demonstrated that the cocaine- and amphetamine-regulated transcript (CART) plays an important role in feeding. However, thus far, the function of CART in gibel carp (Carassius auratus gibelio) feeding regulation has not been reported. In our study, we first identified three forms of CART peptide precursors from gibel carp brain and named these CART-1, CART-2, and CART-3. The full-length cDNA sequences of CART-1, CART-2, and CART-3 were 616 bp, 705 bp, and 760 bp, respectively, encoding peptides of 118, 120, and 104 amino acid residues. We detected mRNA expression of CART-1, CART-2, and CART-3 in a wide range of peripheral and central tissues, with the highest expression detected in the brain. After a meal, mRNA expression of CART-1, CART-2, and CART-3 was significantly elevated, suggesting that CART-1, CART-2, and CART-3 may act as postprandial satiety signals. Moreover, mRNA expression of all three CART-1, CART-2, and CART-3 was significantly reduced during fasting and significantly elevated with refeeding. Our findings indicate that CART-1, CART-2, and CART-3 might function as a satiety factor in the gibel carp.

Speckle Filtering of GF-3 Polarimetric SAR Data with Joint Restriction Principle.

Polarimetric SAR (PolSAR) scattering characteristics of imagery are always obtained from the second order moments estimation of multi-polarization data, that is, the estimation of covariance or coherency matrices. Due to the extra-paths that signal reflected from separate scatterers within the resolution cell has to travel, speckle noise always exists in SAR images and has a severe impact on the scattering performance, especially on single look complex images. In order to achieve high accuracy in estimating covariance or coherency matrices, three aspects are taken into consideration: (1) the edges and texture of the scene are distinct after speckle filtering; (2) the statistical characteristic should be similar to the object pixel; and (3) the polarimetric scattering signature should be preserved, in addition to speckle reduction. In this paper, a joint restriction principle is proposed to meet the requirement. Three different restriction principles are introduced to the processing of speckle filtering. First, a new template, which is more suitable for the point or line targets, is designed to ensure the morphological consistency. Then, the extent sigma filter is used to restrict the pixels in the template aforementioned to have an identical statistic characteristic. At last, a polarimetric similarity factor is applied to the same pixels above, to guarantee the similar polarimetric features amongst the optional pixels. This processing procedure is named as speckle filtering with joint restriction principle and the approach is applied to GF-3 polarimetric SAR data acquired in San Francisco, CA, USA. Its effectiveness of keeping the image sharpness and preserving the scattering mechanism as well as speckle reduction is validated by the comparison with boxcar filters and refined Lee filter.

Evidence that ghrelin may be associated with the food intake of gibel carp (Carassius auratus gibelio).

Ghrelin, a non-amidated peptide hormone, is a potent anorectic neuropeptide implicated in feeding regulation in mammals and non-mammalian vertebrates. However, the involvement of ghrelin in the feeding behavior of teleosts has not been well understood. To better understand the role of ghrelin in the regulation of appetite in fish, in this study, we cloned the cDNAs encoding ghrelin and investigated their mRNA distributions in gibel carp tissues. We also assessed the effects of different nutritional status on ghrelin mRNA abundance. Ghrelin mRNAs were ubiquitously expressed in ten tissues (intestine, liver, brain, mesonephron, head kidney, spleen, skin, heart, muscle, gill and pituitary gland), and relatively high expression levels were detected in the gut. Postprandial studies analysis revealed a significant postprandial decrease in ghrelin mRNA expression in the gut (1 and 3 h after the regular feeding time). In addition, ghrelin mRNA expression in the gut significantly increased at day 7 after fasting and declined sharply after refeeding, which suggested that ghrelin might be involved in the regulation of appetite in gibel carp. Overall, our result provides basis for further investigation into the regulation of feeding in gibel carp.

Molecular characterization of melanin-concentrating hormone (MCH) in Schizothorax prenanti: cloning, tissue distribution and role in food intake regulation.

Melanin-concentrating hormone (MCH) is a crucial neuropeptide involved in various biological functions in both mammals and fish. In this study, the full-length MCH cDNA was obtained from Schizothorax prenanti by rapid amplification of cDNA ends polymerase chain reaction. The full-length MCH cDNA contained 589 nucleotides including an open reading frame of 375 nucleotides encoding 256 amino acids. MCH mRNA was highly expressed in the brain by real-time quantitative PCR analysis. Within the brain, expression of MCH mRNA was preponderantly detected in the hypothalamus. In addition, the MCH mRNA expression in the S. prenanti hypothalamus of fed group was significantly decreased compared with the fasted group at 1 and 3 h post-feeding, respectively. Furthermore, the MCH gene expression presented significant increase in the hypothalamus of fasted group compared with the fed group during long-term fasting. After re-feeding, there was a dramatic decrease in MCH mRNA expression in the hypothalamus of S. prenanti. The results indicate that the expression of MCH is affected by feeding status. Taken together, our results suggest that MCH may be involved in food intake regulation in S. prenanti.

Appetite regulation in Schizothorax prenanti by three CART genes.

In recent years, cocaine- and amphetamine-regulated transcript (CART) has received much attention as mediators of appetite regulation in mammals. However, the involvement of CART in the feeding behavior of teleosts has not been well understood. In this study, three distinct CARTs were cloned from the Schizothorax prenanti (S. prenanti). Real-time quantitative PCR were applied to characterize the tissue distribution and appetite regulatory effects of CARTs in S. prenanti. The S. prenanti CART-1, CART-2 and CART-3 full-length cDNA sequences were 597 bp, 694 bp and 749 bp in length, encoding the peptides of 125, 120 and 104 amino acid residues, respectively. All the S. prenanti CARTs consisted of three exons and two introns. Tissue distribution analysis showed that the high mRNA levels of S. prenanti CART-1 were observed in the telencephalon and eye, followed by the hypothalamus, myelencephalon, and mesencephalon. The S. prenanti CART-2 mRNA was mainly found in the mesencephalon, hypothalamus, telencephalon and myelencephalon. The S. prenanti CART-3 mRNA was widely distributed among the tissues, with the high levels in the hypothalamus and foregut. In the periprandial experiment, all three CARTs mRNA expressions in the hypothalamus were highly elevated after a meal, suggesting that CARTs are postprandial satiety signals. In the fasting experiment, all three CARTs mRNA expressions decreased after fasting and increased after refeeding, suggesting that CARTs might be involved in regulation of appetite in the S. prenanti.

Leptin and cholecystokinin in Schizothorax prenanti: molecular cloning, tissue expression, and mRNA expression responses to periprandial changes and fasting.

In the present study, full-length cDNA sequences of leptin and cholecystokinin (CCK) were cloned from Schizothorax prenanti (S. prenanti), and applied real-time quantitative PCR to characterize the tissue distribution, and appetite regulatory effects of leptin and CCK in S. prenanti. The S. prenanti leptin and CCK full-length cDNA sequences were 1121 bp and 776 bp in length, encoding the peptide of 171 and 123 amino acid residues, respectively. Tissue distribution analysis showed that leptin mRNA was mainly expressed in the liver of S. prenanti. CCK was widely expressed, with the highest levels of expression in the hypothalamus, myelencephalon, telencephalon and foregut of S. prenanti. The CCK mRNA expression was highly elevated after feeding, whereas the leptin mRNA expression was not affected by single meal. These results suggested that CCK is a postprandial satiety signal in S. prenanti, but leptin might not be. In present study, leptin and CCK gene expression were both decreased after fasting and increased after refeeding, which suggested leptin and CCK might be involved in regulation of appetite in S. prenanti. This study provides an essential groundwork to further elucidate the appetite regulatory systems of leptin and CCK in S. prenanti as well as in other teleosts.

Novel MSVPWM to reduce the inductor current ripple for Z-source inverter in electric vehicle applications.

A novel modified space vector pulse width modulation (MSVPWM) strategy for Z-Source inverter is presented. By rearranging the position of shoot-through states, the frequency of inductor current ripple is kept constant. Compared with existing MSVPWM strategies, the proposed approach can reduce the maximum inductor current ripple. So the volume of Z-source network inductor can be designed smaller, which brings the beneficial effect on the miniaturization of the electric vehicle controller. Theoretical findings in the novel MSVPWM for Z-Source inverter have been verified by experiment results.

Schizothorax prenanti corticotropin-releasing hormone (CRH): molecular cloning, tissue expression, and the function of feeding regulation.

Corticotropin-releasing hormone (CRH) is a potent mediator of endocrine, autonomic, behavioral, and immune responses to stress. For a better understanding of the structure and function of the CRH gene and to study its effect on feeding regulation in cyprinid fish, the cDNA of the CRH gene from the brain of Schizothorax prenanti was cloned and sequenced. The full-length CRH cDNA consisted of 1,046 bp with an open reading frame of 489 bp encoding a protein of 162 amino acids. Real-time quantitative PCR analyses revealed that CRH was widely expressed in central and peripheral tissues. In particular, high expression level of CRH was detected in brain. Furthermore, CRH mRNA expression was examined in different brain regions, especially high in hypothalamus. In addition, there was no significant change in CRH mRNA expression in fed group compared with the fasted group in the S. prenanti hypothalamus during short-term fasting. However, CRH gene expression presented significant decrease in the hypothalamus in fasted group compared with the fed group (P < 0.05) on day 7; thereafter, re-feeding could lead to a significant increase in CRH mRNA expression in fasted group on day 9. The results suggest that the CRH may play a critical role in feeding regulation in S. prenanti.

The first chromosomal-level genome assembly and annotation of white suckerfish Remora albescens.

Remora albescens, also known as white suckerfish, recognized for its distinctive suction-cup attachment behavior and medicinal significance. In this study, we produced a high-quality chromosome-level genome assembly of R. albescens through the integration of 23.87 Gb PacBio long reads, 64.54 Gb T7 short reads, and 88.63 Gb Hi-C data. Initially, we constructed a contig-level genome assembly totaling 605.30 Mb with a contig N50 of 23.12 Mb. Subsequently, employing Hi-C technology, approximately 99.68% (603.38 Mb) of the contig-level genome was successfully assigned to 23 pseudo-chromosomes. Through the integration of homologous-based predictions, ab initio predictions, and RNA-sequencing methods, we successfully identified a comprehensive set of 22,445 protein-coding genes. Notably, 96.36% (21,629 genes) of these were effectively annotated with functional information. The genome assembly achieved an estimated completeness of 98.1% according to BUSCO analysis. This work promotes the applicability of the R. albescens genome, laying a solid foundation for future investigations into genomics, biology, and medicinal importance within this species.

The feedback of greening on local hydrothermal conditions in Northern China.

Northern China has experienced a significant increase in vegetation cover over the past few decades. It lacks a comprehensive understanding of how greening impacts local hydrothermal conditions. To address this issue, in our study, the RegCM-CLM45 model was used to conduct a thorough assessment of the impacts of greening on temperature, vapor pressure deficit (VPD), precipitation, and soil moisture. The findings revealed that the local climatic effects of greening varied across different drought gradients based on the aridity index (AI). In drier regions with AI<0.3, the increased energy induced by greening tended to dissipate as sensible heat, exacerbating both warming and drought conditions. Conversely, in wetter regions with AI>0.3, a greater proportion of energy was lost through evapotranspiration, attenuating warming. Additionally, greening enhanced precipitation and soil moisture in drier regions and moderated their decline in wetter regions. Significantly, our research emphasized the effectiveness of grassland expansion and conservation as prime strategies for ecological restoration, particularly in drylands, where they could effectively alleviate soil drought. Given the diverse responses of different land cover transformations to local hydrothermal conditions in drylands, there is an urgent need to address potential adverse effects arising from inappropriate ecological restoration strategies and to develop an optimal restoration framework for the future.

Identification of differences in microRNA transcriptomes between porcine oxidative and glycolytic skeletal muscles.

BACKGROUND: MicroRNAs (miRNAs) are a type of non-coding small RNA ~22 nucleotides in length that regulate the expression of protein coding genes at the post-transcriptional level. Glycolytic and oxidative myofibers, the two main types of skeletal muscles, play important roles in metabolic health as well as in meat quality and production in the pig industry. Previous expression profile studies of different skeletal muscle types have focused on these aspects of mRNA and proteins; nonetheless, an explanation of the miRNA transcriptome differences between these two distinct muscles types is long overdue. RESULTS: Herein, we present a comprehensive analysis of miRNA expression profiling between the porcine longissimus doris muscle (LDM) and psoas major muscle (PMM) using a deep sequencing approach. We generated a total of 16.62 M (LDM) and 18.46 M (PMM) counts, which produced 15.22 M and 17.52 M mappable sequences, respectively, and identified 114 conserved miRNAs and 89 novel miRNA*s. Of 668 unique miRNAs, 349 (52.25%) were co-expressed, of which 173 showed significant differences (P < 0.01) between the two muscle types. Muscle-specific miR-1-3p showed high expression levels in both libraries (LDM, 32.01%; PMM, 20.15%), and miRNAs that potentially affect metabolic pathways (such as the miR-133 and -23) showed significant differences between the two libraries, indicating that the two skeletal muscle types shared mainly muscle-specific miRNAs but expressed at distinct levels according to their metabolic needs. In addition, an analysis of the Gene Ontology (GO) terms and KEGG pathway associated with the predicted target genes of the differentially expressed miRNAs revealed that the target protein coding genes of highly expressed miRNAs are mainly involved in skeletal muscle structural development, regeneration, cell cycle progression, and the regulation of cell motility. CONCLUSION: Our study indicates that miRNAs play essential roles in the phenotypic variations observed in different muscle fiber types.

Breed, sex and anatomical location-specific gene expression profiling of the porcine skeletal muscles.

BACKGROUND: Skeletal muscle is one of the most important economic traits in agricultural animals, especially in pigs. In the modern pig industry, lean type pigs have undergone strong artificial selection for muscle growth, which has led to remarkable phenotypic variations compared with fatty type pigs, making these different breeds an ideal model for comparative studies. RESULTS: Here, we present comprehensive gene expression profiling for the white (longissimus dorsi muscle) and the red (psoas major muscle) skeletal muscles among male and female fatty Rongchang, feral Tibetan and lean Landrace pigs, using a microarray approach. We identified differentially expressed genes that may be associated the phenotypic differences of porcine muscles among the breeds, between the sexes and the anatomical locations. We also used a clustering method to identify sets of functionally coexpressed genes that are linked to different muscle phenotypes. We showed that, compared with the white muscles, which primarily modulate metabolic processes, the red muscles show a tendency to be a risk factor for inflammation and immune-related disorders. CONCLUSIONS: This analysis presents breed-, sex- and anatomical location-specific gene expression profiles and further identified genes that may be associated with the phenotypic differences in porcine muscles among breeds, between the sexes and the anatomical locations.