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Objectives: To investigate the utility of deep learning (DL) automated segmentation-based MRI radiomic features and clinical-radiological characteristics in predicting early recurrence after curative resection of single hepatocellular carcinoma (HCC). Methods: This single-center, retrospective study included consecutive patients with surgically proven HCC who underwent contrast-enhanced MRI before curative hepatectomy from December 2009 to December 2021. Using 3D U-net-based DL algorithms, automated segmentation of the liver and HCC was performed on six MRI sequences. Radiomic features were extracted from the tumor, tumor border extensions (5 mm, 10 mm, and 20 mm), and the liver. A hybrid model incorporating the optimal radiomic signature and preoperative clinical-radiological characteristics was constructed via Cox regression analyses for early recurrence. Model discrimination was characterized with C-index and time-dependent area under the receiver operating curve (tdAUC) and compared with the widely-adopted BCLC and CNLC staging systems. Results: Four hundred and thirty-four patients (median age, 52.0 years; 376 men) were included. Among all radiomic signatures, HCC with5 mmtumorborderextensionandliver showed the optimal predictive performance (training set C-index, 0.696). By incorporating this radiomic signature, rim arterial phase hyperenhancement (APHE), and incomplete tumor "capsule," a hybrid model demonstrated a validation set C-index of 0.706 and superior 2-year tdAUC (0.743) than both the BCLC (0.550; p < 0.001) and CNLC (0.635; p = 0.032) systems. This model stratified patients into two prognostically distinct risk strata (both datasets p < 0.001). Conclusion: A preoperative imaging model incorporating the DL automated segmentation-based radiomic signature with rim APHE and incomplete tumor "capsule" accurately predicted early postsurgical recurrence of a single HCC. Critical relevance statement: The DL automated segmentation-based MRI radiomic model with rim APHE and incomplete tumor "capsule" hold the potential to facilitate individualized risk estimation of postsurgical early recurrence in a single HCC. Key Points: A hybrid model integrating MRI radiomic signature was constructed for early recurrence prediction of HCC. The hybrid model demonstrated superior 2-year AUC than the BCLC and CNLC systems. The model categorized the low-risk HCC group carried longer RFS. [ABSTRACT FROM AUTHOR]

Objectives: Contrast-enhanced MRI can provide individualized prognostic information for hepatocellular carcinoma (HCC). We aimed to investigate the value of MRI features to predict early (≤ 2 years)/late (> 2 years) recurrence-free survival (E-RFS and L-RFS, respectively) and overall survival (OS). Materials and methods: Consecutive adult patients at a tertiary academic center who received curative-intent liver resection for very early to intermediate stage HCC and underwent preoperative contrast-enhanced MRI were retrospectively enrolled from March 2011 to April 2021. Three masked radiologists independently assessed 54 MRI features. Uni- and multivariable Cox regression analyses were conducted to investigate the associations of imaging features with E-RFS, L-RFS, and OS. Results: This study included 600 patients (median age, 53 years; 526 men). During a median follow-up of 55.3 months, 51% of patients experienced recurrence (early recurrence: 66%; late recurrence: 34%), and 17% died. Tumor size, multiple tumors, rim arterial phase hyperenhancement, iron sparing in solid mass, tumor growth pattern, and gastroesophageal varices were associated with E-RFS and OS (largest p =.02). Nonperipheral washout (p =.006), markedly low apparent diffusion coefficient value (p =.02), intratumoral arteries (p =.01), and width of the main portal vein (p =.03) were associated with E-RFS but not with L-RFS or OS, while the VICT2 trait was specifically associated with OS (p =.02). Multiple tumors (p =.048) and radiologically-evident cirrhosis (p <.001) were the only predictors for L-RFS. Conclusion: Twelve visually-assessed MRI features predicted postoperative E-RFS (≤ 2 years), L-RFS (> 2 years), and OS for very early to intermediate-stage HCCs. Clinical relevance statement: The prognostic MRI features may help inform personalized surgical planning, neoadjuvant/adjuvant therapies, and postoperative surveillance, thus may be included in future prognostic models. Key Points: • Tumor size, multiple tumors, rim arterial phase hyperenhancement, iron sparing, tumor growth pattern, and gastroesophageal varices predicted both recurrence-free survival within 2 years and overall survival. • Nonperipheral washout, markedly low apparent diffusion coefficient value, intratumoral arteries, and width of the main portal vein specifically predicted recurrence-free survival within 2 years, while the VICT2 trait specifically predicted overall survival. • Multiple tumors and radiologically-evident cirrhosis were the only predictors for recurrence-free survival beyond 2 years. [ABSTRACT FROM AUTHOR]

Deltamethrin (Del), a widely administered pyrethroid insecticide, has been established as a common contaminant of the freshwater environment and detected in many freshwater ecosystems. In this study, we investigated the changes in brain transcriptome and metabolome of crucian carp after exposure to 0.6 μg/L Del for 28 days. Elevated MDA levels and inhibition of SOD activity indicate damage to the antioxidant system. Moreover, a total of 70 differential metabolites (DMs) were identified using the liquid chromatography‐mass spectrometry, including 32 upregulated and 38 downregulated DMs in the Del‐exposed group. The DMs associated with chronic Del exposure were enriched in steroid hormone biosynthesis, fatty acid metabolism, and glycerophospholipid metabolism for prostaglandin G2, 5‐oxoeicosatetraenoic acid, progesterone, androsterone, etiocholanolone, and hydrocortisone. Transcriptomics analysis revealed that chronic Del exposure caused lipid metabolism disorder, endocrine disruption, and proinflammatory immune response by upregulating the pla2g4, cox2, log5, ptgis, lcn, and cbr expression. Importantly, the integrative analysis of transcriptomics and metabolomics indicated that the arachidonic acid metabolism pathway and steroid hormone biosynthesis were decisive processes in the brain tissue of crucian carp after Del exposure. Furthermore, Del exposure perturbed the tight junction, HIF‐1 signaling pathway, and thyroid hormone signaling pathway. Overall, transcriptome and metabolome data of our study offer a new insight to assess the risk of chronic Del exposure in fish brains. [ABSTRACT FROM AUTHOR]

Background: Hepatocellular carcinoma (HCC) expressing cytokeratin (CK) 7 or CK19 has a cholangiocyte phenotype that stimulates HCC proliferation, metastasis, and sorafenib therapy resistance This study aims to noninvasively predict cholangiocyte phenotype-positive HCC and assess its prognosis after hepatectomy. Methods: Between January 2010 and May 2022, preoperative contrast-enhanced MRI was performed on consecutive patients who underwent hepatectomy and had pathologically confirmed solitary HCC. Two abdominal radiologists separately assessed the MRI features. A predictive model for cholangiocyte phenotype HCC was created using logistic regression analysis and five-fold cross-validation. A receiver operating characteristic curve was used to calculate the model performance. Kaplan–Meier and log-rank methods were used to evaluate survival outcomes. Results: In total, 334 patients were included in this retrospective study. Four contrast-enhanced MRI features, including "rim arterial phase hyperenhancement" (OR = 5.9, 95% confidence interval [CI]: 2.9–12.0, 10 points), "nodule in nodule architecture" (OR = 3.5, 95% CI: 2.1–5.9, 7 points), "non-smooth tumor margin" (OR = 1.6, 95% CI: 0.8–2.9, 3 points), and "non-peripheral washout" (OR = 0.6, 95% CI: 0.3–1.0, − 3 points), were assigned to the cholangiocyte phenotype HCC prediction model. The area under the curves for the training and independent validation set were 0.76 and 0.73, respectively. Patients with model-predicted cholangiocyte phenotype HCC demonstrated lower rates of recurrence-free survival (RFS) and overall survival (OS) after hepatectomy, with an estimated median RFS and OS of 926 vs. 1565 days (p < 0.001) and 1504 vs. 2960 days (p < 0.001), respectively. Conclusions: Contrast-enhanced MRI features can be used to predict cholangiocyte phenotype-positive HCC. Patients with pathologically confirmed or MRI model-predicted cholangiocyte phenotype HCC have a worse prognosis after hepatectomy. Critical relevance statement: Four contrast-enhanced MRI features were significantly associated with cholangiocyte phenotype HCC and a worse prognosis following hepatectomy; these features may assist in predicting prognosis after surgery and improve personalized treatment decision-making. Key points: • Four contrast-enhanced MRI features were significantly associated with cholangiocyte phenotype HCC. • A noninvasive cholangiocyte phenotype HCC predictive model was established based on MRI features. • Patients with cholangiocyte phenotype HCC demonstrated a worse prognosis following hepatic resection. [ABSTRACT FROM AUTHOR]

Objective: To develop and validate a risk score based on preoperative clinical-radiological parameters for predicting overall survival (OS) in patients undergoing surgical resection for hepatocellular carcinoma (HCC). Methods: From July 2010 to December 2021, consecutive patients with surgically-proven HCC who underwent preoperative contrast-enhanced MRI were retrospectively enrolled. A preoperative OS risk score was constructed in the training cohort using a Cox regression model and validated in a propensity score-matched internal validation cohort and an external validation cohort. Results: A total of 520 patients were enrolled, among whom 210, 210, and 100 patients were from the training, internal validation, and external validation cohorts, respectively. Independent predictors for OS included incomplete tumor "capsule," mosaic architecture, tumor multiplicity, and serum alpha-fetoprotein, which were incorporated into the "OSASH score." The C-index the OSASH score was 0.85, 0.81, and 0.62 in the training, internal, and external validation cohorts, respectively. Using 32 as the cutoff point, the OSASH score stratified patients into prognostically distinct low- and high-risk groups among all study cohorts and six subgroups (all p < 0.05). Furthermore, patients with BCLC stage B-C HCC and OSASH-low risk achieved comparable OS to that of patients with BCLC stage 0-A HCC and OSASH-high risk in the internal validation cohort (5-year OS rates, 74.7 vs. 77.8%; p = 0.964). Conclusion: The OSASH score may help predict OS in HCC patients undergoing hepatectomy and identify potential surgical candidates among those with BCLC stage B-C HCC. Clinical relevance statement: By incorporating three preoperative MRI features and serum AFP, the OSASH score may help predict postsurgical overall survival in patients with hepatocellular carcinoma and identify potential surgical candidates among those with BCLC stage B and C HCC. Key Points: • The OSASH score incorporating three MRI features and serum AFP can be used to predict OS in HCC patients who received curative-intent hepatectomy. • The score stratified patients into prognostically distinct low- and high-risk strata in all study cohorts and six subgroups. • Among patients with BCLC stage B and C HCC, the score identified a subgroup of low-risk patients who achieved favorable outcomes after surgery. [ABSTRACT FROM AUTHOR]

Background: To establish a preoperative score based on gadoxetate disodium-enhanced magnetic resonance imaging (EOB-MRI) and clinical indicators for predicting histologic differentiation of solitary HCC up to 5 cm. Methods: From July 2015 to January 2022, consecutive patients with surgically proven solitary HCC measuring ≤ 5 cm at preoperative EOB-MRI were retrospectively enrolled. All MR images were independently evaluated by two radiologists who were blinded to all clinical and pathologic information. Univariate and multivariate logistic regression analyses were performed to identify significant clinicoradiological features associated with poorly differentiated (PD) HCC, which were then incorporated into the predictive score. The predictive score was validated in an independent validation set by area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and accuracy. Results: A total of 182 patients were included, 42 (23%) with PD HCC. According to the multivariate analysis, marked hepatobiliary phase hypointensity (odds ratio [OR], 9.98), LR-M category (OR, 5.60), and serum alpha-fetoprotein (AFP) level > 400 ng/mL (OR, 3.58) were incorporated into the predictive model; the predictive score achieved an AUC of 0.802 and 0.830 on the training and validation sets, respectively. The sensitivity, specificity, and accuracy of the predictive score were 66.7%, 85.7%, and 81.3%, respectively, on the training set and 66.7%, 81.0%, and 77.8%, respectively, on the validation set. Conclusion: The proposed score integrating two EOB-MRI features and AFP level can accurately predict PD HCC in the preoperative setting. Key points: EOB-MRI features help capture the characteristics of tumor biology and heterogeneity. EOB-MRI-based HCC differentiation score allowed accurate assessment of poor tumor differentiation preoperatively. This scoring system might be useful for prompting tailored treatment selection. [ABSTRACT FROM AUTHOR]

Objectives: To establish a risk score integrating preoperative gadoxetic acid–enhanced magnetic resonance imaging (EOB-MRI) and clinical parameters to predict recurrence after hepatectomy for patients with hepatocellular carcinoma (HCC) and to compare its performance with that of a postoperative score and four clinical staging systems. Methods: Consecutive patients with surgically confirmed HCC who underwent preoperative EOB-MRI between July 2015 and November 2020 were retrospectively included. Two recurrence risk scores, one incorporating only preoperative variables and the other incorporating all preoperative and postoperative variables, were constructed via Cox regression models. Results: A total of 214 patients (derivation set, n = 150; test set, n = 64) were included. Six preoperative variables, namely tumor number, infiltrative appearance, corona enhancement, alpha-fetoprotein (AFP) level, aspartate aminotransferase (AST) level, and sex, were independently associated with recurrence. After adding postoperative features, microvascular invasion and tumor differentiation were additional significant variables in lieu of corona enhancement and AFP level. Using the above variables, the preoperative score achieved a C-index of 0.741 on the test set, which was comparable with that of the postoperative score (0.729; p = 0.235). The preoperative score yielded a larger time-dependent area under the receiver operating characteristic curve at 1 year (0.844) than three existing systems (0.734–0.742; p < 0.05 for all). Furthermore, the preoperative score stratified patients into two prognostically distinct risk strata with low and high risks of recurrence (p < 0.001). Conclusion: The preoperative score integrating EOB-MRI features, AFP and AST levels, and sex improves recurrence risk estimation in HCC. Key Points: • The preoperative risk score incorporating three EOB-MRI findings, AFP and AST levels, and sex achieved comparable performance with that of the postoperative score for predicting recurrence after hepatectomy in patients with HCC. • Two risk strata with low and high risks of recurrence were obtained based on the preoperative score. • The preoperative score may help tailor pretreatment decision-making and facilitate candidate selection for adjuvant clinical trials. [ABSTRACT FROM AUTHOR]

Background: The Liver Imaging Reporting and Data System (LI‐RADS) is widely used for diagnosing hepatocellular carcinoma (HCC), however, with unsatisfactory sensitivity, complex ancillary features, and inadequate integration with gadoxetate disodium (EOB)‐enhanced MRI. Purpose: To modify LI‐RADS (mLI‐RADS) on EOB‐MRI. Study Type: Secondary analysis of a prospective observational study. Population: Between July 2015 and September 2018, 224 consecutive high‐risk patients (median age, 51 years; range, 26–83; 180 men; training/testing sets: 169/55 patients) with 742 (median size, 13 mm; interquartile range, 7–27; 498 HCCs) LR‐3/4/5 observations. Field Strength/Sequence: 3.0 T T2‐weighted fast spin‐echo, diffusion‐weighted spin‐echo based echo‐planar, and 3D T1‐weighted gradient echo sequences. Assessment: Three radiologists (with 5, 5, and 10 years of experience in liver MR imaging, respectively) blinded to the reference standard (histopathology or imaging follow‐up) reviewed all MR images independently. In the training set, the optimal LI‐RADS version 2018 (v2018) features selected by Random Forest analysis were used to develop mLI‐RADS via decision tree analysis. Statistical Tests: In an independent testing set, diagnostic performances of mLI‐RADS, LI‐RADS v2018, and the Korean Liver Cancer Association (KLCA) guidelines were computed using a generalized estimating equation model and compared with McNemar's test. A two‐tailed P < 0.05 was statistically significant. Results: Five features (nonperipheral "washout," restricted diffusion, nonrim arterial phase hyperenhancement [APHE], mild–moderate T2 hyperintensity, and transitional phase hypointensity) constituted mLI‐RADS, and mLR‐5 was nonperipheral washout coupled with either nonrim APHE or restricted diffusion. In the testing set, mLI‐RADS was significantly more sensitive (72%) and accurate (80%) than LI‐RADS v2018 (sensitivity, 61%; accuracy 74%; both P < 0.001) and the KLCA guidelines (sensitivity, 64%; accuracy 74%; both P < 0.001), without sacrificing positive predictive value (mLI‐RADS, 94%; LI‐RADS v2018, 94%; KLCA guidelines, 92%). Data Conclusion: In high‐risk patients, the EOB‐MRI‐based mLI‐RADS was simpler and more sensitive for HCC than LI‐RADS v2018 while maintaining high positive predictive value. Level of Evidence: 2 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]

Background: The Liver Imaging Reporting and Data System (LI‐RADS) is widely accepted as a reliable diagnostic scheme for hepatocellular carcinoma (HCC) in at‐risk patients. However, its application is hampered by substantial complexity and suboptimal diagnostic sensitivity. Purpose: To propose data‐driven modifications to the LI‐RADS version 2018 (v2018) major feature system (rLI‐RADS) on gadoxetate disodium (EOB)‐enhanced magnetic resonance imaging (MRI) to improve sensitivity and simplicity while maintaining high positive predictive value (PPV) for detecting HCC. Study Type: Retrospective. Population: Two hundred and twenty‐four consecutive at‐risk patients (training dataset: 169, independent testing dataset: 55) with 742 LR‐3 to LR‐5 liver observations (HCC: N = 498 [67%]) were analyzed from a prospective observational registry collected between July 2015 and September 2018. Field Strength/Sequence: 3.0 T/T2‐weighted fast spin‐echo, diffusion‐weighted spin‐echo based echo‐planar and three‐dimensional (3D) T1‐weighted gradient echo sequences. Assessment: All images were evaluated by three independent abdominal radiologists who were blinded to all clinical, pathological, and follow‐up information. Composite reference standards of either histopathology or imaging follow‐up were used. Statistical Tests: In the training dataset, LI‐RADS v2018 major features were used to develop rLI‐RADS based on their associated PPV for HCC. In an independent testing set, diagnostic performances of LI‐RADS v2018 and rLI‐RADS were computed using a generalized estimating equation model and compared with McNemar's test. A P value <0.05 was considered statistically significant. Results: The median (interquartile range) size of liver observations was 13 mm (7–27 mm). The diagnostic table for rLI‐RADS encompassed 9 cells, as opposed to 16 cells for LI‐RADS v2018. In the testing set, compared to LI‐RADS v2018, rLI‐RADS category 5 demonstrated a significantly superior sensitivity (76% vs. 61%) while maintaining comparably high PPV (92.5% vs. 94.1%, P = 0.126). Data Conclusion: Compared with LI‐RADS v2018, rLI‐RADS demonstrated improved simplicity and significantly superior diagnostic sensitivity for HCC in at‐risk patients. Level of Evidence: 3 Technical Efficacy Stage: 2 [ABSTRACT FROM AUTHOR]

Being the largest extant amphibian in the world, the IUCN Critically Endangered Chinese giant salamander Andrias davidianus is a charismatic species with great international public interest. While threats such as commercial overexploitation and habitat degradation have been extensively documented to affect natural populations of A. davidianus, still no information is available about the species sensitivity to climate change.Here, we develop an ensemble of species distribution models (SDMs) for A. davidianus and projected its habitat suitability under present‐day and future climate change scenarios. We based our SDMs on bioclimatic and topographic predictors, and recent (2012–2018) field‐collected occurrence data across the whole distribution range of the species.The ensemble SDMs exhibited good predictive capacity and suggested that slope, maximum temperature of warmest month, precipitation of driest month, and isothermality are the most influential predictors in determining distribution patterns in this species. The projections of our models point to a pronounced impact of climate changes over A. davidianus, with more than two‐thirds of its suitable range expected to be lost in all scenarios of future climates tested.In concert with the numerous other threats that are affecting this species, climate change poses a serious hindrance to the long‐term survival of A. davidianus. We emphasise the urgent need of undertaking strict measures to manage this species and safeguard the few remaining available suitable habitats. We suggest that adaptive management strategies including designation of new reserves should be considered to mitigate the impacts of climate change on A. davidianus. [ABSTRACT FROM AUTHOR]

The characterization of the expression and regulation of growth-related genes in the muscles of Chinese perch is of great interest to aquaculturists because of the commercial value of the species. The transcriptome annotation of the skeletal muscles is a crucial step in muscle growth-related gene analysis. In this study, we generated 52 504 230 reads of mRNA sequence data from the fast muscles of the Chinese perch by using Solexa/Illumina RNA-seq. Twenty-one amino acid transporter genes were annotated by searching protein and gene ontology databases, and postprandial changes in their transcript abundance were assayed after administering a single satiating meal to Chinese perch juveniles (body mass, approximately 100 g), following fasting for 1 week. The gut content of the Chinese perch increased significantly after 1 h and remained high for 6 h following the meal and emptied within 48–96 h. Expression of eight amino acid transporter genes was assayed in the fast muscles through quantitative real-time polymerase chain reaction at 0, 1, 3, 6, 12, 24, 48, and 96 h. Among the genes, five transporter transcripts were markedly up-regulated within 1 h of refeeding, indicating that they may be potential candidate genes involved in the rapid-response signaling system regulating fish myotomal muscle growth. These genes display coordinated regulation favoring the resumption of myogenesis responding to feeding. [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome of the hybrid ofCyprinus capio Furong(♀) × Carassius auratus red var.(♂) was characterized first in this study. The total length of the mitochondrial genome ofFurong-crucianwas identical to the female parent as 16,581 bp, and the overall base composition was 31.87% A, 24.81% T, 27.56% C and 15.76% G, with a slight A + T bias. It contained 13 protein-coding genes (PCGs), 22 transfer RNA genes, 2 ribosomal RNA genes and 2 main non-coding regions (the control region and the origin of the light-strand replication). This study discovered the 99.3% sequence identity between the hybrid and its female parent, which confirmed the maternal inheritance pattern followed by the mitochondrial genome of the hybrid. However, the sequence alignment of mitochondrial genomes between the hybrid and its female parent revealed a total of 109 variable sites in 18 genes or regions, especially 32 sense mutations in 9 PCGs. The complete mitochondrial genome sequence of this hybridFurong-crucianmay provide an important dataset for further study in mitochondrial inheritance mechanism. [ABSTRACT FROM PUBLISHER]

The complete mitochondrial genome of the hybrid ofCyprinus carpio L. mirror(♀)× Cyprinus Carpio var. singuonensis(♂) was characterized first in this study. The total length of the genome was identical to the female parent as 16,581 bp, and the overall base composition was 31.80% A, 24.85% T, 27.55% C and 15.80% G, with a slight A + T bias. It contained 13 protein-coding genes (PCGs), 22 transfer RNA genes, 2 ribosomal RNA genes and 2 main non-coding regions (the control region and the origin of the light-strand replication). This study discovered the 99.70% sequence identity between the hybrid and its female parent, which confirmed the maternal inheritance pattern followed by the mitochondrial genome of the hybrid. However, the sequence alignment of mitochondrial genomes between the hybrid and its female parent revealed a total of 47 variable sites in 15 genes or regions, especially 25 sense mutations in 6 PCGs. The complete mitochondrial genome sequence of the hybridCyprinus capio Furongmay provide an important dataset for further study in mitochondrial inheritance mechanism. [ABSTRACT FROM PUBLISHER]

In this study, 16 sets of primers were used to amplify contiguous, overlapping segments of the complete mitochondrial DNA (mtDNA) ofDanio chrysotaenitusin order to characterize and compare their mitochondrial genomes. The total length of the mitochondrial genome is 16,608 bp and deposited in the GenBank with accession numbers KP407138. The organization of the mitochondrial genomes was similar to those reported from other Mountain carp fishes mitochondrial genomes containing 37 genes (13 protein-coding genes, 2 ribosomal RNA, and 22 transfer RNAs) and a major non-coding control region (D-loop region). Most genes were encoded on the H-strand, except for the ND6 and 8 tRNA genes, encoding on the L-strand. The nucleotide skewness for the coding strands ofDanio chrysotaenitus(AT-skew = 0.10, GC-skew = −0.25) is biased toward T and G. The complete mitogenome may provide important date set for the study of genetic mechanism ofDanio chrysotaenitus. [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome ofVanmanenia pingchowensiswas determined in this study. The gene composition, arrangement and transcriptional orientation inV. pingchowensismitogenome were identical to most vertebrates. The complete mitogenome ofV. pingchowensiswas 15,560 bp in size with 13 protein coding genes, 22 tRNA genes, and a control region. Two start codon patterns and three stop codon patterns were found in protein-coding genes. Only the tRNA-Ser2 could not fold into a typical clover-leaf secondary structure for lacking the dihydrouridine arm. Sequences alignment results suggest that the complete mitogenome ofV. pingchowensisis an efficient tool to study molecular phylogenetics, biogeography and adaptive evolution of this lineage. [ABSTRACT FROM PUBLISHER]

The complete mitochondrial genome ofParasinilabeo assimilishas been determined in this study. The gene composition, arrangement and transcriptional orientation inP. assimilismitogenome were identical to most vertebrates. The complete mitogenome ofP. assimiliswas 16,602 bp in size with 13 protein coding genes, 22 tRNA genes and a control region. Two start codon patterns and three stop codon patterns were found in protein-coding genes. Only the tRNA-Ser2 could not fold into a typical clover-leaf secondary structure due to the lack of the dihydrouridine arm. Sequence alignment results suggest that the complete mitogenome ofP. assimilisis an efficient tool to study molecular phylogenetics, biogeography and adaptive evolution of this lineage. [ABSTRACT FROM PUBLISHER]

The peripheral tissue pacemaker is responsive to light and other zeitgebers, especially food availability. Generally, the pacemaker can be reset and entrained independently of the central circadian structures. Studies involving clock-gene expressional patterns in fish peripheral tissues have attracted considerable attention. However, the rhythmic expression of clock genes in skeletal muscle has only scarcely been investigated. The present study was designed to investigate the core clock and functional gene expression rhythms in crucian carp. Meanwhile, the synchronized effect of food restrictions (short-term fasting) on these rhythms in skeletal muscle was carefully examined. In fed crucian carp, three core clock genes (Clock, Bmal1a, and Per1) and five functional genes (Epo, Fas, IGF1R2, Jnk1, and MyoG) showed circadian rhythms. By comparison, four core clock genes (Clock, Bmal1a, Cry3, and Per2) and six functional genes (Epo, GH, IGF2, Mstn, Pnp5a, and Ucp1) showed circadian rhythms in crucian carp muscle after 7-day fasting. In addition, three core clock genes (Clock, Per1, and Per3) and six functional genes (Ampk1a, Lpl, MyoG, Pnp5a, PPARα, and Ucp1) showed circadian rhythms in crucian carp muscle after 15-day fasting. However, all gene rhythmic expression patterns differed from each other. Furthermore, it was found that the circadian genes could be altered by feed deprivation in crucian carp muscle through the rhythms correlation analysis of the circadian genes and functional genes. Hence, food-anticipatory activity of fish could be adjusted through the food delivery restriction under a light–dark cycle. These results provide a potential application in promoting fish growth by adjusting feeding conditions and nutritional state. [ABSTRACT FROM AUTHOR]