The silent threat: Nanopolystyrene and chrysene pollutants disrupt the intestinal mucosal barrier, new insights from juvenile Siniperca chuatsi.

The intestinal mucosal barrier-comprising microbial, mechanical, chemical, and immunological barriers-is critical to protection against pathogens and maintenance of host health; however, it remains unclear whether it is affected by environmental contaminants. Therefore, the present study assessed whether exposure to ambient concentrations of nanopolystyrene (NP) and chrysene (CHR)-two ubiquitous environmental pollutants in the aquatic environment-affect the intestinal mucosal barrier in juvenile Siniperca chuatsi. After exposure for 21 days, S. chuatsi exhibited intestinal oxidative stress and imbalance of intestinal microbial homeostasis. NP and/or CHR exposure also disrupted the intestinal mechanical barrier, as evidenced by the altered intestinal epithelial cell morphology, disrupted structure of intercellular tight junctions, and decreased expression of tight junction proteins. Damage to the intestinal chemical barrier manifested as thinning of the mucus layer owing to the loss and damage of goblet cells. Furthermore, the intestinal immunological barrier was impaired as indicated by the loss of intestinal intraepithelial lymphocytes and increase in pro-inflammatory cytokines, chemokines, and immunoglobulins. These findings collectively suggest that the intestinal mucosal barrier was damaged. This study is, to the best of our knowledge, the first to report that exposure to NP and/or CHR at environmentally relevant concentrations disrupts the intestinal mucosal barrier in organisms and highlight the significance of nanoplastic/CHR pollution for intestinal health.

Nanoplastics and chrysene pollution: Potential new triggers for nonalcoholic fatty liver disease and hepatitis, insights from juvenile Siniperca chuatsi.

Nanopolystyrene (NP) and chrysene (CHR) are ubiquitous contaminants in the natural environment; however, research on their hepatotoxicity and associated adverse effects remains relatively inadequate. The present study aimed to investigate the hepatotoxic effects of NP and/or CHR at environmentally relevant concentrations, as well as the underlying molecular mechanisms, in juvenile Siniperca chuatsi (mandarin fish). After a 21-day exposure period, the livers of exposed S. chuatsi exhibited macrostructural and microstructural damage accompanied by oxidative stress. Importantly, our study provides the first evidence that NP exposure leads to the development of nonalcoholic fatty liver disease (NAFLD) and hepatitis in S. chuatsi. Similarly, CHR exposure has also been found, for the first time, to cause hepatic sinusoidal dilatation (HSD) and hepatitis. Exposure to the combination of NP and CHR alleviated the symptoms of NAFLD, HSD, and hepatitis. Furthermore, our comprehensive multi-omic analysis revealed that the pathogenesis of NP-induced NAFLD was mainly due to induction of the triglyceride synthesis pathway and inhibition of the very-low-density lipoprotein secretion process. CHR induced HSD primarily through a reduction in vasoprotective ability and smooth muscle contractility. Hepatitis was induced by activation of the JAK-STAT/NF-kappa B signaling pathways, which upregulated the expression of inflammation-specific genes. Collectively, results of this study offer novel insight into the multiple hepatotoxicity endpoints of NP and/or CHR exposure at environmentally relevant concentrations in organisms, and highlight the importance of nanoplastic/CHR pollution for liver health.

Identification of antimicrobial peptide genes from transcriptomes in Mandarin fish (Siniperca chuatsi) and their response to infection with Aeromonas hydrophila.

Mandarin fish (Siniperca chuatsi) is a valuable freshwater fish species widely cultured in China. Its aquaculture production is challenged by bacterial septicaemia, which is one of the most common bacterial diseases. Antimicrobial peptides (AMPs) play a critical role in the innate immune system of fish, exhibiting defensive and inhibitory effects against a wide range of pathogens. This study aimed to identify the antimicrobial peptide genes in mandarin fish using transcriptomes data obtained from 17 tissue in our laboratory. Through nucleotide sequence alignment and protein structural domain analysis, 15 antimicrobial peptide genes (moronecidin, pleurocidin, lysozyme g, thymosin ß12, hepcidin, leap 2, ß-defensin, galectin 8, galectin 9, apoB, apoD, apoE, apoF, apoM, and nk-lysin) were identified, of which 9 antimicrobial peptide genes were identified for the first time. In addition, 15 AMPs were subjected to sequence characterization and protein structure analysis. After injection with Aeromonas hydrophila, the number of red blood cells, hemoglobin concentration, and platelet counts in mandarin fish showed a decreasing trend, indicating partial hemolysis. The expression change patterns of 15 AMP genes in the intestine after A. hydrophila infection were examined by using qRT-PCR. The results revealed, marked up-regulation (approximately 116.04) of the hepcidin gene, down-regulation of the piscidin family genes expression. Moreover, most AMP genes were responded in the early stages after A. hydrophila challenge. This study provides fundamental information for investigating the role of the different antimicrobial peptide genes in mandarin fish in defense against A. hydrophila infection.

Gastrointestinal perforation in extremely low birth weight infants: A single center retrospective study in China.

BACKGROUND: Gastrointestinal perforation in extremely low birth weight infants, characterized by its rapid onset, multiple complications, and critical condition, poses a significant risk of infant mortality. The aim of this study was to investigate the clinical characteristics of pneumoperitoneum in extremely low birth weight infants (ELBWI) and explore the risk factors associated with gastrointestinal perforation in very low birth weight preterm infants. Additionally, we shared our surgical experiences in managing gastrointestinal perforation among extremely low birth weight infants. METHODS: The Department of Neonatology at Chengdu Women and Children's Central Hospital conducted a retrospective study on gastrointestinal perforation in extremely low birth weight infants (birth weight <1000 g) who were admitted between 2014 and 2021. After baseline analysis and comparing it with the control group, we identified the risk factors associated with gastrointestinal perforation in ELBWI by multiple logistic regression analysis. The Kaplan-Meier analysis was performed to assess the adverse effect of gastrointestinal perforation for survival in ELBW infants. Cox multivariate regression analysis was used to evaluate hazard level of different variables for ELBW infants survival. RESULTS: Hemodynamically significant patent ductus arteriosus (hsPDA)(p = 0.043, OR = 2.779) and sepsis (p = 0.014, OR = 2.265) were significant risk factors for gastrointestinal perforation in extremely low birth weight infants. The Cox proportional hazard model revealed that intraventricular hemorrhage (HR = 2.854, p＜0.001) Sepsis (HR = 1.645, p = 0.015) and gastrointestinal perforation (HR = 1.876, p = 0.008) had detrimental effects on the survival of extremely low birth weight infants; conversely, ibuprofen (HR = 0.304, p＜0.001) and blood transfusion (HR = 0.372, p＜0.001) are beneficial factors for their survival. The preoperative indicators of infection in infants with spontaneous intestinal perforation (SIP) were significantly better than those in the necrotizing enterocolitis (NEC) group (p < 0.05). CONCLUSIONS: Gastrointestinal perforation poses a significant threat the survival of extremely low birth weight (ELBW) infants, with hsPDA and sepsis serving as predisposing factors for gastrointestinal perforation. The gastrointestinal perforation caused by various diseases exhibits distinct clinical characteristics, necessitating tailored surgical approaches based on operative conditions.

The fusion gene hsf5-rnf43 in Nile tilapia: A potential regulator in the maintenance of testis function and sexual differentiation.

We identified that the genes heat shock transcription factor 5 (hsf5) and ring finger protein 43 (rnf43) happened fusion in Nile tilapia (Oreochromis niloticus), called hsf5-rnf43, and provided the characteristic and functional analysis of hsf5-rnf43 gene in fish for the first time. Analysis of spatiotemporal expression showed that hsf5-rnf43 was specifically expressed in the testis and located in primary spermatocytes of adult Nile tilapia and gradually increased during testis development from 5 to 180 days after hatching. We also found DNA methylation regulated sex-biased expression of hsf5-rnf43 in the early development of Nile tilapia, and was affected by high temperature during the thermosensitive period of Nile tilapia sex differentiation. Therefore, we first reported that the fusion gene hsf5-rnf43 was sex-biased expressed in the testis regulated by DNA methylation and affected by high temperature, which may be involved in the maintenance of testis function and sex differentiation of Nile tilapia.

Effects of chloride, sulfate, and bicarbonate stress on mortality rate, gill tissue morphology, and gene expression in mandarin fish (Siniperca chuatsi).

The mandarin fish Siniperca chuatsi is a freshwater fish that is endemic to East Asia. To study the different damages and molecular mechanisms caused by different salt (NaCl, Na2SO4, and NaHCO3) on Siniperca chuatsi, the fish were subjected to NaCl, Na2SO4, and NaHCO3 stresses with different concentration for 96 h for mortality assessment, moreover, the fish were exposed to these salt stresses with equal sodium ion concentration (Na+ = 210 mmol/L), then gill morphological changes were observed and gene expression was analyzed by high-throughput transcriptome sequencing and real-time quantitative PCR (qRT-PCR). The results showed that mandarin fish tolerated NaCl and Na2SO4 better than NaHCO3. NaHCO3 stress caused more damage to gill than NaCl and Na2SO4 stress. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses indicated that differentially expressed genes were enriched in damage and apoptosis upon NaHCO3 stress, whereas they were enriched in energy and immune-related pathways upon NaCl and Na2SO4 stress. Hub genes were different under all three stresses. MAPK pathway genes showed a trend in up-regulated expression under all salt stresses, but the expression patterns varied with time during salt exposure and freshwater recovery stage. Taken together, this study demonstrated the variation in the effects of NaCl, Na2SO4, and NaHCO3 stress on mandarin fish. The MAPK signaling pathway is important for regulating the response to salt stress.

Impacts of exposure to nanopolystyrene and/or chrysene at ambient concentrations on neurotoxicity in Siniperca chuatsi.

Health risks caused by widespread environmental pollutants such as nanopolystyrene (NP) and chrysene (CHR) in aquatic ecosystems have aroused considerable concern. The present study established juvenile Mandarin fish (Siniperca chuatsi) models of NP and/or CHR exposure at ambient concentrations for 21 days to systematically investigate the underlying neurotoxicity mechanisms. The results showed that single and combined exposure to NP and CHR not only reduced the density of small neuronal cells in the grey matter layer of the optic tectum, but also induced brain oxidative stress according to physiological parameters including CAT, GSH-Px, SOD, T-AOC, and MDA. The co-exposure alleviated the histopathological damage, compared to NP and CHR single exposure group. These results indicate that NP and/or CHR causes neurotoxicity in S. chuatsi, in accordance with decreased acetylcholinesterase activity and altered expression of several marker genes of nervous system functions and development including c-fos, shha, elavl3, and mbpa. Transcriptomics analysis was performed to further investigate the potential molecular mechanisms of neurotoxicity. We propose that single NP and co-exposure induced oxidative stress activates MMP, which degrades tight junction proteins according to decreased expression of claudin, JAM, caveolin and TJP, ultimately damaging the integrity of the blood-brain barrier in S. chuatsi. Remarkably, the co-exposure exacerbated the blood-brain barrier disruption. More importantly, single NP and co-exposure induced neuronal apoptosis mainly activates the expression of apoptosis-related genes through the death receptor apoptosis pathway, while CHR acted through both death receptor apoptosis and endoplasmic reticulum apoptosis pathways. Additionally, subchronic CHR exposure caused neuroinflammation, supported by activation of TNF/NF-κB and JAK-STAT signaling pathways via targeting-related genes, while the co-exposure greatly alleviated the neuroinflammation. Collectively, our findings illuminate the underlying neurotoxicity molecular mechanisms of NP and/or CHR exposure on aquatic organisms.

Identification of hub genes in digestive system of mandarin fish (Siniperca chuatsi) fed with artificial diet by weighted gene co-expression network analysis.

Mandarin fish (Siniperca chuatsi) is a carnivorous freshwater fish and an economically important species. The digestive system (liver, stomach, intestine, pyloric caecum, esophagus, and gallbladder) is an important site for studying fish domestication. In our previous study, we found that mandarin fish undergoes adaptive changes in histological morphology and gene expression levels of the digestive system when subjected to artificial diet domestication. However, we are not clear which hub genes are highly associated with domestication. In this study, we performed WGCNA on the transcriptomes of 17 tissues and 9 developmental stages and combined differentially expressed genes analysis in the digestive system to identify the hub genes that may play important functions in the adaptation of mandarin fish to bait conversion. A total of 31,657 genes in 26 samples were classified into 23 color modules via WGCNA. The modules midnightblue, darkred, lightyellow, and darkgreen highly associated with the liver, stomach, esophagus, and gallbladder were extracted, respectively. Tan module was highly related to both intestine and pyloric caecum. The hub genes in liver were cp, vtgc, c1in, c9, lect2, and klkb1. The hub genes in stomach were ghrl, atp4a, gjb3, muc5ac, duox2, and chia2. The hub genes in esophagus were mybpc1, myl2, and tpm3. The hub genes in gallbladder were dyst, npy2r, slc13a1, and slc39a4. The hub genes in the intestine and pyloric caecum were slc15a1, cdhr5, btn3a1, anpep, slc34a2, cdhr2, and ace2. Through pathway analysis, modules highly related to the digestive system were mainly enriched in digestion and absorption, metabolism, and immune-related pathways. After domestication, the hub genes vtgc and lect2 were significantly upregulated in the liver. Chia2 was significantly downregulated in the stomach. Slc15a1, anpep, and slc34a2 were significantly upregulated in the intestine. This study identified the hub genes that may play an important role in the adaptation of the digestive system to artificial diet, which provided novel evidence and ideas for further research on the domestication of mandarin fish from molecular level.

Chromosome-scale assembly and quantitative trait locus mapping for major economic traits of the Culter alburnus genome using Illumina and PacBio sequencing with Hi-C mapping information.

Topmouth culter (Culter alburnus) is an economically important freshwater fish with high nutritional value. However, its potential genetic advantages have not been fully exploited. Therefore, we aimed to determine the genome sequence of C. alburnus and examine quantitative trait loci (QTLs) related to major economic traits. The results showed that 24 pseudochromosomes were anchored by 914.74 Mb of the C. alburnus genome sequence. De novo sequencing identified 31,279 protein-coding genes with an average length of 8507 bp and average coding sequ ence of 1115 bp. In addition, a high-density genetic linkage map consisting of 24 linkage groups was constructed based on 353,532 high-quality single nucleotide polymorphisms and 4,710 bin markers. A total of 28 QTLs corresponding to 11 genes, 26 QTLs corresponding to 11 genes, and 12 QTLs corresponding to 5 genes were identified for sex, intermuscular spine number and body weight traits, respectively. In this study, we assembled an accurate and nearly complete genome of C. alburnus by combining Illumina, PacBio, and high-throughput Chromosome conformation capture (Hi-C) technologies. In addition, we identified QTLs that explained variances in intermuscular spine number, body weight, and sex differences in C. alburnus. These genetic markers or candidate genes associated with growth traits provide a basis for marker-assisted selection in C. alburnus.

Comparative genomics revealed drastic gene difference in two small Chinese perches, Siniperca undulata and S. obscura.

Siniperca undulata and S. obscura (Centrarchiformes: Sinipercidae) are small Chinese perches, living in creeks and streams in southern China. While they have sympatric distribution and occupy similar macrohabitat, their body sizes and ecological niches have many differences. Determining the genome sequences of S. undulata and S. obscura would provide us an essential data set for better understanding their genetic makeup and differences that may play important roles in their adaptation to different niches. We determined the genome sequences of both S. undulata and S. obscura using 10× genomics technology and the next-generation sequencing. The assembled genomes of S. undulata and S. obscura were 744 and 733 Mb, respectively. Gene family analysis revealed that there were no overlap between S. undulata and S. obscura in terms of rapid expanding and rapid contracting genes families, which were related to growth, immunity, and mobility. Positive selection analyses also cooperated that the function of selected genes involve growth, athletic ability, and immunity, which may explain the preference of different niches by S. undulata and S. obscura. Pairwise sequentially Markovian coalescent analyses for the two species suggested that populations of both S. undulata and S. obscura showed a rising trend between 90 and 70 Ka probably due to the mild environment during the last interglacial period. A stage of population shrinking occurred from 70 to 20 Ka, which was in with the Tali glacial period in eastern China (57-16 Ka).

Physiological monitoring of intensity training in female wrestlers / Monitoramento fisiológico no treino físico de intensidade em lutadoras femininas / Monitoreo fisiológico en el entrenamiento físico de intensidad en las luchadoras femeninas

ABSTRACT Introduction Currently, female wrestling has become one of the potential advantages in the Olympic Games, which has also allowed the sport to receive more attention. Physiological monitoring in intense physical training in female wrestlers is still little explored despite its importance in training conduction. Objective Explore special intensity physical training effects on female wrestlers through physiological monitoring. Methods Literature search, expert interview, and an experimental method conducted a situation analysis on 2-month training for 8 female wrestling team athletes, specific contents also included: analysis of female wrestlers' body composition, changes in serum testosterone levels, and variations in cortisol levels. Results During the two-month training period, the various athletes' physiological indicators underwent noticeable changes, remaining at the top of the normal range. Most of the athletes could adapt to the training load and intensity in this phase. Serum testosterone, cortisol, and hemoglobin levels in early athletes increased significantly. However, as training progresses, all indicators decrease, showing that the adaptability of the athlete's body is consolidated. The hemoglobin content increased in most of the athletes, showing that the athlete's own intensity of physical training was high. Conclusion The above physiological indicators can reflect the physical function of the athletes, providing a theoretical basis for coaches to develop evidence-based training plans. Evidence Level II; Therapeutic Studies - Investigating the result.

RESUMO Introdução Atualmente, a luta livre feminina tornou-se uma das vantagens potenciais dos Jogos Olímpicos, o que também permitiu que o esporte recebesse maior atenção. O monitoramento fisiológico no treino físico de intensidade em lutadoras femininas ainda é pouco explorado apesar da sua importância na condução do treinamento. Objetivo Explora os efeitos do treinamento físico especial para a intensidade em lutadoras femininas através de monitoramento fisiológico. Métodos Pesquisa literária, entrevista com especialistas e o método experimental levaram a uma análise da situação sobre o treinamento de 2 meses para 8 atletas da equipe de luta livre feminina, os conteúdos específicos incluíram: análise da composição corporal das lutadoras, alterações nos níveis séricos de testosterona e variações nos níveis de cortisol. Resultados Durante o período de dois meses de treinamento, os vários indicadores fisiológicos das atletas sofreram alterações perceptíveis, permanecendo no limite alto da faixa normal. A maioria das atletas pode se adaptar à carga e intensidade do treinamento nesta fase. Os níveis de testosterona sérica, cortisol e hemoglobina nas atletas precoces aumentaram significativamente. Porém, à medida que o treinamento progride, todos os indicadores diminuem, mostrando que a adaptabilidade do corpo da atleta é consolidada. O conteúdo de hemoglobina aumentou na maioria das atletas, mostrando que o treino físico de intensidade da própria atleta foi elevado. Conclusão Os indicadores fisiológicos acima podem refletir a função física das atletas, fornecendo uma base teórica para que os treinadores possam desenvolver planos de treinamento baseados em evidências. Nível de evidência II; Estudos Terapêuticos - Investigação de Resultados.

RESUMEN Introducción En la actualidad, la lucha femenina se ha convertido en una de las ventajas potenciales de los Juegos Olímpicos, lo que también ha permitido que este deporte reciba más atención. El seguimiento fisiológico en el entrenamiento físico de intensidad en las luchadoras es todavía poco explorado a pesar de su importancia en la conducción del entrenamiento. Objetivo Explorar los efectos del entrenamiento físico especial para la intensidad en las luchadoras a través de la monitorización fisiológica. Métodos La investigación bibliográfica, la entrevista a expertos y el método experimental condujeron a un análisis de situación sobre 2 meses de entrenamiento de 8 atletas del equipo femenino de lucha, los contenidos específicos incluían: análisis de la composición corporal de las luchadoras, cambios en los niveles séricos de testosterona y variaciones en los niveles de cortisol. Resultados Durante los dos meses de entrenamiento, los diversos indicadores fisiológicos de los atletas sufrieron cambios notables, manteniéndose en el extremo superior del rango normal. La mayoría de los atletas pudieron adaptarse a la carga e intensidad del entrenamiento en esta fase. Los niveles de testosterona, cortisol y hemoglobina en suero de los primeros atletas aumentaron significativamente. Sin embargo, a medida que el entrenamiento avanza, todos los indicadores disminuyen, lo que demuestra que la adaptabilidad del cuerpo del atleta se consolida. El contenido de hemoglobina aumentó en la mayoría de los atletas, lo que demuestra que el entrenamiento físico de intensidad propia fue alto. Conclusión Los indicadores fisiológicos anteriores pueden reflejar la función física de los atletas, proporcionando una base teórica para que los entrenadores desarrollen planes de entrenamiento basados en pruebas. Nivel de evidencia II; Estudios terapéuticos - Investigación de resultados.

Runners sports injuries and rehabilitation / Lesões esportivas e reabilitação em praticantes de corrida / Lesiones deportivas y rehabilitación en corredores

ABSTRACT Introduction Independent athletes and sports enthusiasts are subject to injuries due to several factors, such as neglect of physical preparation, lack of knowledge of the evolutionary progression of load intensity, and deficient stretching. Running is a popular sport in China, and the knowledge of the injuries caused by this group of fans may guide awareness behaviors to prevent accidents in sports practice. Objective Evaluate the injuries and rehabilitation of runners. Methods A total of 265 ordinary chinese runners (166 men) were selected as research subjects. Information on running sports injury characteristics, subjective perception of the causes of runners' injuries, prevention and rehabilitation methods in runners' injuries were evaluated. Results The knee joint has the highest proportion of injuries (26.73%), followed by foot injuries (13.11%) and ankle injuries (10.65%). Pain after exercise was reported by 38.12% of the runners, while 21.89% felt pain during the race. Conclusion Warm-up exercises are recommended before sports practice. Protective equipment can reduce the probability of injuries. Such equipment is considered a method of treatment and prevention with greater satisfaction and better adherence among runners. Evidence Level II; Therapeutic Studies - Investigating the result.

RESUMO Introdução Atletas independentes e entusiastas esportivos estão sujeitos a lesões por vários fatores como negligência do preparo físico, desconhecimento na progressão evolutiva de intensidade de carga e alongamentos deficitários. A corrida é um esporte popular na China e o conhecimento das lesões ocasionadas nesse grupo de adeptos poderá guiar condutas de conscientização para a prevenção de acidentes na prática esportiva. Objetivo Avaliar as lesões e a reabilitação nos praticantes de corrida. Métodos Um total de 265 corredores comuns chineses (166 homens) foram selecionados como objetos de pesquisa. Foram avaliadas as informações sobre as características das lesões esportivas de corrida, a percepção subjetiva das causas das lesões dos corredores, métodos de prevenção e reabilitação nas lesões dos corredores. Resultados A articulação do joelho apresenta a maior proporção nas lesões (26,73%), seguida por lesões nos pés (13,11%) e tornozelos (10,65%). Dores após o exercício foram relatadas por 38,12% dos corredores enquanto 21,89% dos corredores sentem dor durante a corrida. Conclusão Recomenda-se a realização de exercícios de aquecimento antes da prática esportiva. Os equipamentos de proteção podem reduzir a probabilidade das lesões. A utilização desses equipamentos é considerada um método de tratamento e prevenção com maior satisfação e melhor adesão entre os corredores. Nível de evidência II; Estudos Terapêuticos - Investigação de Resultados.

RESUMEN Introducción Los atletas independientes y los entusiastas del deporte están sujetos a lesiones por varios factores como la negligencia en la preparación física, la falta de conocimiento en la progresión de la intensidad de la carga y los estiramientos deficientes. La corrida es un deporte muy popular en China y el conocimiento de las lesiones causadas en este grupo de aficionados puede orientar las conductas de concienciación para la prevención de accidentes en la práctica deportiva. Objetivo Evaluar las lesiones y la rehabilitación en los practicantes de corrida. Métodos Un total de 265 corredores chinos ordinarios (166 hombres) fueron seleccionados como sujetos de la investigación. Se evaluó la información sobre las características de las lesiones deportivas de los corredores, la percepción subjetiva de las causas de las lesiones de los corredores y los métodos de prevención y rehabilitación en las lesiones de los corredores. Resultados La articulación de la rodilla es la que presenta la mayor proporción de lesiones (26,73%), seguida por las del pie (13,11%) y las del tobillo (10,65%). El 38,12% de los corredores declararon dolor después del ejercicio, mientras que el 21,89% de los corredores sintieron dolor durante la carrera. Conclusión Se recomienda realizar ejercicios de calentamiento antes de la práctica deportiva. El equipo de protección puede reducir la probabilidad de lesiones. El uso de estos equipos se considera un método de tratamiento y prevención con mayor satisfacción y mejor adherencia entre los corredores. Nivel de evidencia II; Estudios terapéuticos - Investigación de resultados.

Characterization of kiss2/kissr2 system in largemouth bass (Micropterus salmoides) and Kiss2-10 peptide regulation of the hypothalamic-pituitary-gonadal axis.

The kisspeptin system, which lies upstream of the hypothalamic-pituitary-gonadal (HPG) axis, is believed to function as a regulator of reproduction in teleosts. In this study, we isolated and characterized kiss2 and its receptor kissr2 in largemouth bass (Micropterus salmoides). The complete coding sequences of kiss2 and kissr2 were 375 and 1134 bp long and encoded precursor proteins 124 and 377 amino acid long, respectively. Real-time PCR showed that kiss2 and kissr2 were primarily expressed in the HPG axis. The expression profile of kiss2 and kissr2 varied with gonadal development, with the highest and lowest expression levels being detected during the immature and final maturation stages, respectively. Intraperitoneal injection of exogenous Kiss2-10 peptide increased the transcript levels of gnrh3, kissr2, fshß, lhß, ar, and er2 within 24 h (p < 0.05), as well as plasma levels of 17ß-estradiol and testosterone. Histological analysis indicated that chronic administration of exogenous Kiss2-10 peptide accelerated vitellogenesis in females and spermatogenesis in males. Further, in situ hybridization revealed that kiss2 is expressed in the ooplasm and vitelline envelope of oocytes and the spermatocytes of testes. In addition, experiments using gonad tissue primary cell cultures indicated that exogenous Kiss2-10 peptide stimulates the expression of reproduction-related genes. Collectively, our findings indicate that the kiss2/kissr2 system in largemouth bass is involved in regulating gonadal development through the HPG axis.

Gene expression profiling of DNA methyltransferase genes in Siniperca chuatsi based on transcriptome sequencing.

The mandarin fish (Siniperca chuatsi) DNA methyltransferase gene 1 (dnmt1) was highly expressed in the mesonephros, head kidney and gonad, whereas dnmt2 was expressed in most tissues. dnmt3a was highly expressed in the brain and spleen, but dnmt3b was mainly expressed in the brain and head kidney. The genes dnmt1 and dnmt2 were highly expressed in the early stages of embryonic development, and dnmt3a and dnmt3b were expressed later. These genes also showed certain changes after artificial diet acclimation, salinity adaptation and immune stress.

Promoter methylation and expression of the rassf4 gene in Nile tilapia (Oreochromis niloticus).

Oreochromis niloticus RAS-association domain family 4 (rassf4) was specifically expressed in the ovaries. Immunohistochemistry results showed that Rassf4 was located in follicular cells. The methylation percentages of the promoter region (-734/-1012) of rassf4 in the ovaries and testes were 13.28% and 92.85%, respectively. Deleting the fragment of -734 to -1012 sites significantly reduced the basal activity of the rassf4 promoter to 62.33%, which indicated that this region was important for the transcription of the rassf4 gene. This study lays the foundation for further research on the function of fish rassf4.

Physical Investigations on Bias-Free, Photo-Induced Hall Sensors Based on Pt/GaAs and Pt/Si Schottky Junctions.

Hall-effect in semiconductors has wide applications for magnetic field sensing. Yet, a standard Hall sensor retains two problems: its linearity is affected by the non-uniformity of the current distribution; the sensitivity is bias-dependent, with linearity decreasing with increasing bias current. In order to improve the performance, we here propose a novel structure which realizes bias-free, photo-induced Hall sensors. The system consists of a semi-transparent metal Pt and a semiconductor Si or GaAs to form a Schottky contact. We systematically compared the photo-induced Schottky behaviors and Hall effects without net current flowing, depending on various magnetic fields, light intensities and wavelengths of Pt/GaAs and Pt/Si junctions. The electrical characteristics of the Schottky photo-diodes were fitted to obtain the barrier height as a function of light intensity. We show that the open-circuit Hall voltage of Pt/GaAs junction is orders of magnitude lower than that of Pt/Si, and the barrier height of GaAs is smaller. It should be attributed to the surface states in GaAs which block the carrier drifting. This work not only realizes the physical investigations of photo-induced Hall effects in Pt/GaAs and Pt/Si Schottky junctions, but also opens a new pathway for bias-free magnetic sensing with high linearity and sensitivity comparing to commercial Hall-sensors.

Genomic and expression characterization of aquaporin genes from Siniperca chuatsi.

Aquaporins (AQPs) are major intrinsic proteins that form pores in the membranes of biological cells. We first cloned the full-length sequences of aqp0, 1, 3, 4, 7, 8, 9, 10, 11, and 12 genes in Siniperca chuatsi. The 10 S. chuatsi aqp (Sc-aqp) genes included complete open reading frames and exhibited different exon-intron organizations. Sc-aqp1, 3, 8, 9, 10, and 11 were mostly expressed in the gallbladder, gills, gastric cecum, liver, ovaries, and spleen, respectively; Sc-aqp0 and 4 were mostly expressed in larvae at 1 day after hatching and in gastrula; Sc-aqp7 and 12 were mostly expressed in 2K-cell embryos. The expression levels of Sc-aqp1, 3, 7, 8, 9, and 10 after 10 part per thousand (ppt) salt treatment had significantly changed compared with those after 0 ppt salt treatment. Real-time quantitative PCR analysis further showed that in the intestines, the mRNA levels of Sc-aqp1 and 10 significantly decreased by approximately 2.07- and 2.85-fold, respectively, whereas those of Sc-aqp8 and 9 significantly increased by approximately 7.08- and 4.14-fold, respectively. Sc-aqp1, 8, 9, and 10 showed no significant differences in the gills. Sc-aqp3 significantly decreased by approximately 1.51- and 1.67-fold in the gills and intestines, respectively. Sc-aqp7 significantly increased by approximately 4.18- and 7.04-fold in the gills and intestines, respectively. This study was the first to investigate the tissue expression profiles and response to salt stress of aqp genes in S. chuatsi. Moreover, altering diet and suffering from immune stress could cause changes in the expression level of aqps. This study provided valuable reference information for AQPs' roles in osmoregulation in freshwater fish.