Heterogeneity of neuromasts in a fish without lateral line canals: the pufferfish (Takifugu obscurus) model.

Fish detect water motion with their mechanosensory lateral line. The basic functional unit of the lateral line is the neuromast. In most fish species, neuromasts are located in lateral line canals (canal neuromasts) or on the skin (superficial neuromasts). In this paper, we describe the lateral line system of the pufferfish, Takifugu obscurus If threatened, this fish inflates its body by sucking water into the esophagus. Pufferfish lack a canal system but have neuromasts located directly on the skin or in open grooves. Each groove houses tall, medium and short neuromasts, based on the height of their pedestal. One or more medium neuromasts were always located between two tall neuromasts, and the short neuromasts were scattered between them. Tall neuromasts showed phasic responses to water jets, similar to the canal neuromasts of other fish species. In contrast, the medium and short neuromasts showed tonic responses to water jets. The response properties of nerve fibers that innervated the medium and short neuromasts were similar to those of the superficial neuromasts found in other fish species. Our results suggest that each groove of a pufferfish has two functional groups of neuromasts. This may allow pufferfish to extract spatial and temporal hydrodynamic information, despite the changes in body shape that occur during and after inflation. The short neuromasts at the bottom of a groove most likely supplement the medium neuromasts when the body is maximally inflated.

Potent antioxidative and UVB protective effect of water extract of Eclipta prostrata L.

Oxidative stress, including Ultraviolet (UV) irradiation-induced skin damage, is involved in numerous diseases. This study demonstrates that water extract of Eclipta prostrata L. (WEP) has a potent effect in scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide radicals, and chelating ferrous ion, exhibiting IC50 values of 0.23 mg/mL, 0.48 mg/mL, and 1.25 mg/mL, respectively. The WEP total phenol content was 176.45 mg gallic acid equivalents (GAE)/g sample. Chlorogenic acid, a component of the plant's active ingredients, was determined by HPLC and antioxidative assay. However, no caffeic acid, stigmasterol, or wedelolactone was present in WEP. WEP absorbs both UVA and UVB irradiation, and furthermore, the extract shows a dose-dependent response in the protection of HaCaT human keratinocytes and mouse fibroblasts 3T3 cells against UVB-induced cytotoxicity, which may result from a synergistic effect between chlorogenic acid and other active components present in WEP.

Recruitment Patterns and Environmental Sensitivity of Glass Eels of Anguilla japonica in the Yangtze Estuary, China.

The decline of Japanese eel (Anguilla japonica) populations in the Yangtze River estuary represents a critical conservation concern. Eleven-years of daily catch data during recruitment periods (i.e., January-April, 2012-2022) indicate that annual catch averaged from 153 to 1108 eels, and show a bimodal pattern in glass eel arrivals. Utilizing seasonal-trend decomposition and generalized additive models, we demonstrated a strong correlation between catch abundance, optimal water temperatures, and lunar cycles. An auto-regressive integrated moving average (ARIMA) model predicts an increase in glass eel numbers for 2023-2024 but also points to a concerning trend of delayed recruitment timing since 2016, attributable to the 0.48 °C per decade rise in sea surface temperatures. This delay correlates with a significant decrease in the average body weight of glass eels, suggesting potential energy deficits that may hinder successful upstream migration. This study not only furthers our understanding of glass eel recruitment dynamics but also underscores the urgent need for targeted conservation measures. Additionally, it highlights the importance of sustained, detailed monitoring to mitigate the detrimental effects of climate change on these eels, vital for preserving the Yangtze River's ecological integrity.

Comprehensive diagnosis and treatment of ductal carcinoma of the submandibular gland: case report and literature review.

Salivary duct carcinoma (SDC) is a rare malignant tumor of the salivary gland and is most commonly found in the parotid gland, followed by the submandibular gland. Due to its rarity, there is no consensus on its treatment. Surgical resection is currently the only curative treatment. Considering its high degree of malignancy, extensive tumor resection and postoperative adjuvant radiotherapy are recommended. We report a rare case of SDC of the submandibular gland. A 62-year-old man presented to our hospital with complaints of swelling in the right submaxillary area for 4 months, rapidly growing, with pain for 10 days. After admission, fine needle aspiration (FNA) revealed right submandibular gland ductal carcinoma. Considering its aggressiveness, large size, and invasion of parapharyngeal and oral floor soft tissues, the patient received two cycles of neoadjuvant chemotherapy followed by extended surgical resection. Postoperatively, the patient received four cycles of concurrent chemoradiotherapy, followed by afatinib targeted therapy. No recurrence or metastasis was observed in a 45-month follow-up. Thus we present a comprehensive treatment for salivary duct carcinoma combining neoadjuvant chemotherapy with surgery, postoperative concurrent radiotherapy, and chemotherapy followed by afatinib targeted therapy.

Comparative evolution of S7 Intron 1 and ribosomal internal transcribed spacer in Coilia nasus (Clupeiformes: Engraulidae).

Coilia nasus is widely distributed in the Yangtze River, the coastal waters of China, Korea and the Ariake Sound of Japan. Several ecotypes exist and this provides a useful model for the study of comparative diversity between molecular markers. Here we analyze and compare the nucleotide sequences between single-copy ribosomal protein S7 gene intron 1 (rpS7) and multiple-copy ribosomal internal transcribed spacer 1 (ITS1) in this species to compare the phylogenetic signal of the two nuclear genes. Nucleotide substitutions among the two gene sequences and partial sequence of mitochondrial cytochrome c oxidase subunit I (COI) gene were also analyzed. A total of 115 clones for rpS7 and 122 clones for ITS1 were obtained from 37 specimens. The nucleotide sequence length is 741 to 743 bp for rpS7 and 334 to 348 bp for ITS1. Intra- and inter-specimen variation in rpS7 results from nucleotide substitution, while such variation in ITS1 is mainly due to different numbers of short base repeats. The content of G + C is lower in rpS7 (43.5%) than in ITS1 (68.2%). Our results indicate that the proportion of the sequence variable sites is higher in rpS7 (61) than in ITS1 (23); the informative parsimony of rpS7 is evidently higher than that of ITS1 (26 vs. 2); the overall ratio between transitions and transversions in ITS1 is slightly lower than in rpS7, but remarkably lower than in COI. These results suggest that rpS7 is more suitable than ITS1 as a marker for genetic divergence of this group. Furthermore, gene flow is observed between the different geographic populations of C. nasus from the phylogeny of this species based on rpS7, showing that rpS7 has more evolutionary characteristics for understanding the processes of genomic evolution at the intraspecific level.

PCR and magnetic bead-mediated target capture for the isolation of short interspersed nucleotide elements in fishes.

Short interspersed nucleotide elements (SINEs), a type of retrotransposon, are widely distributed in various genomes with multiple copies arranged in different orientations, and cause changes to genes and genomes during evolutionary history. This can provide the basis for determining genome diversity, genetic variation and molecular phylogeny, etc. SINE DNA is transcribed into RNA by polymerase III from an internal promoter, which is composed of two conserved boxes, box A and box B. Here we present an approach to isolate novel SINEs based on these promoter elements. Box A of a SINE is obtained via PCR with only one primer identical to box B (B-PCR). Box B and its downstream sequence are acquired by PCR with one primer corresponding to box A (A-PCR). The SINE clone produced by A-PCR is selected as a template to label a probe with biotin. The full-length SINEs are isolated from the genomic pool through complex capture using the biotinylated probe bound to magnetic particles. Using this approach, a novel SINE family, Cn-SINE, from the genomes of Coilia nasus, was isolated. The members are 180-360 bp long. Sequence homology suggests that Cn-SINEs evolved from a leucine tRNA gene. This is the first report of a tRNA(Leu)-related SINE obtained without the use of a genomic library or inverse PCR. These results provide new insights into the origin of SINEs.

Comparative transcriptomic analysis reveals potential mechanisms for high tolerance to submergence in arbor willows.

BACKGROUND: Submergence threatens plant growth and survival by decreasing or eliminating oxygen supply. Uncovering the complex regulatory network underlying the tolerance of Salix to submergence and identifying the key regulators are important for molecular-assisted breeding of Salix. METHODS: In this study, we screened germplasm resources of arbor willows and discovered both submergence-tolerant and submergence-sensitive varieties. Then, by performing RNA-seq, we compared the differences between the transcriptomes of two varieties, i.e., the submergence-tolerant variety "Suliu 795" and the submergence-sensitive variety "Yanliu No. 1," and the different submergence treatment time points to identify the potential mechanisms of submergence in Salix and the unique approaches by which the variety "Suliu 795" possessed a higher tolerance compared to "Yanliu No. 1". RESULTS: A total of 22,790 differentially expressed genes were identified from 25 comparisons. Using gene ontology annotation and pathway enrichment analysis, the expression pattern of transcriptional factors, important players in hormone signaling, carbohydrate metabolism, and the anaerobic respiration pathway were found to differ significantly between the two varieties. The principal component analysis and qRT-PCR results verified the reliability of the RNA sequencing data. The results of further analysis indicated that "Suliu 795" had higher submergence tolerant activity than "Yanliu No. 1" because of three characteristics: (1) high sensitivity to the probable low oxygen stress and initiation of appropriate responding mechanisms in advance; (2) maintenance of energy homeostasis to prevent energy depletion under hypoxic stress; and (3) keep "quiescence" through fine-tuning the equilibrium between phytohormones GA, SA and ethylene.

Chromosome-level genome assembly of the endangered humphead wrasse Cheilinus undulatus: Insight into the expansion of opsin genes in fishes.

Wrasses are dominant components of major coral reef systems. Among wrasses, Cheilinus undulatus is an endangered species with high economic and ecological value that exhibits sex reversal of females to males, while sexual selection occurs in breeding aggregations. However, the molecular-associated mechanism underlying this remains unclear. Opsin gene diversification is regarded as a potent force in sexual selection. Here we present a genome assembly of C. undulatus, using Illumina, Nanopore and Hi-C sequencing. The 1.17 Gb genome was generated from 328 contigs with an N50 length of 16.5 Mb and anchored to 24 chromosomes. In total, 22,218 genes were functionally annotated, and 96.36% of BUSCO genes were fully represented. Transcriptomic analyses showed that 96.79% of the predicted genes were expressed. Transposons were most abundant, accounting for 39.88% of the genome, with low divergence, owing to their evolution with close species ~60.53 million years ago. In total, 567/1,826 gene families were expanded and contracted in the reconstructed phylogeny, respectively. Forty-six genes were under positive selection. Comparative genomic analyses with other fish revealed expansion of opsin SWS2B, LWS1 and Rh2. The elevated duplicates of SWS2B were generated by gene conversions via transposition of transposons followed by nonallelic homologous recombination. Amino acid substitutions of opsin paralogues occurred at key tuning sites, causing a spectral shift in maximal absorbance of visual pigment to capture functional changes. Among these opsin genes, SWS2B-3 and 4 and Rh1 are expressed in the retina. The genome sequence of C. undulatus provides valuable resources for future investigation of the conservation, evolution and behaviour of fishes.

Integrated analysis of blood mRNAs and microRNAs reveals immune changes with age in the Yangtze finless porpoise (Neophocaena asiaeorientalis).

Populations of Yangtze finless porpoises (YFPs) have rapidly declined in recent decades, raising the specter of extinction. In order to protect YFPs, a greater understanding of their biology is needed, including studying how their immune functioning changes with age. Here, we systematically studied the hematologic and biochemical parameters, as well as mRNAs and miRNAs profiles of old, adult, and young YFPs. The lymphocyte (LYMPH), neutrophils (NEUT) and eosinophils (EOS) counts in old YFPs were lower than those in young or adult YFPs. When comparing old to adult YFPs, the latter showed higher expression of genes associated with the innate and adaptive immune systems, including complement components, major histocompatibility complex, interleukins, TNF receptors, and chemokines/cytokines. When comparing old to young YFPs, the most striking difference was in higher toll-like receptor signaling in the latter. When comparing adult to young YFPs, the former exhibited higher expression of genes related to adaptive immunity and the FoxO signaling pathway, but lower expression of genes associated with the PI3K-Akt signaling pathway. Negative miRNA-mRNA interactions were predicted in comparisons of the old and adult (326), old and young (316), adult and young (211) groups. Overall, these results delineate a progression from early innate immune function dominance to adaptive immune function enhancement (young to adult) and deterioration (adult to old), and the changes in miRNAs profile correlate with the effects of age on immune functions. This study is the first to observe the changes of immune function of Yangtze finless porpoise with age using transcriptome method, and the study's findings are of great significance for protecting this endangered species.

Sound production in marbled rockfish (Sebastiscus marmoratus) and implications for fisheries.

Recently, several rockfish species (genus Sebastes) have been reported to be soniferous. To determine whether an additional rockfish species produces sounds, passive acoustic recordings were analyzed from captive marbled rockfish (Sebastiscus marmoratus) during the non-spawning season. Three distinct sounds were identified based on frequency features. The common characteristics among all sounds were low frequency (below 300 Hz) and rapidly dampened pulses consisting of 3-5 acoustic energy cycles. During free-swimming conditions in the canvas tank, the fish produced voluntary sounds with lower frequencies than the disturbance sounds produced by individuals during prodding. Two types of sounds were identified in the disturbance context: one type consists of single or double pulses with two peak frequencies, and another type consists of a series of pulses with a single peak frequency. These results suggest that specific-species and behavior-associated sounds are potentially useful in passive acoustical surveys to monitor rockfish populations and distributions remotely.

Use of electrosense in the feeding behavior of sturgeons.

The electro-receptive lateral line system appeared early in the evolutionary history of fish. Sturgeons, members of the primitive Chondrostei group, are known for their electroreceptors (ampullae of Lorenzini) on the head, which are thought to be sensitive to weak electric fields in aquatic environments and involved in feeding, mating and migration. Here, we report the results of a set of behavioral and electrophysiological experiments designed to determine the function and characteristics of the electrosense in cultured sturgeons. The results showed Siberian sturgeon (Acipenser baerii Brandt, 1869) feeding striking at bio-electric fields produced by living feed-fish enclosed in a gel chamber and at the corrosion field produced by metal rods. With an electric stimulus that mimics the bio-electric fields produced by living prey, the relative discharge rate of electrosensory neurons in the dorsal octavolateralis nucleus (DON) was modulated by and phase-locked to sinusoidal stimulus and some units showed selectivity for dipolar direction in white sturgeon (Acipenser transmontanus Richardson, 1836). This is the first study to provide the empirical evidence correlating with electrosensory behaviors and electrophysiological responses in cultured sturgeons, and suggesting that electrosense does play an innate role in feeding behavior of sturgeon. We believe this will have important implications for protecting sturgeons in the wild.

Response properties of the electrosensory neurons in hindbrain of the white sturgeon, Acipenser transmontanus.

OBJECTIVE: The passive electrosense is a primitive sensory modality in the Chondrostei, which include sturgeon and paddlefish. Using electroreceptors, these fish detect the weak electric fields from other animals or geoelectric sources, and use this information for prey detection or other behaviors. The primary afferent fibers innervating the electroreceptors project to a single hindbrain target called the dorsal octavolateral nucleus (DON), where the electrosensory information is first processed. Here, we investigated the electrophysiological properties of DON neurons. METHODS: Extracellular recording was used to investigate the response properties of DON neurons to dipole electric fields with different amplitudes and frequencies in the white sturgeon, Acipenser transmontanus. RESULTS: The DON neurons showed regular spontaneous activity and could be classified into two types: neurons with a low spontaneous rate (<10 Hz) and those with a high spontaneous rate (>10 Hz). In response to sinusoidal electric field stimuli, DON neurons showed sinusoidally-modulated and phase-locked firing. In addition, neurons showed opposite phase responses corresponding to the different directions of the dipole. CONCLUSION: The response properties of DON neurons match the electrosensory biological function in sturgeon, as they match the characteristics of the electric fields of its prey.

Behavioral migration diversity of the Yangtze River Japanese Eel, Anguilla japonica, based on otolith Sr/Ca ratios.

The Yangtze River estuary is the main production area of Anguilla japonica in China, as well as the only existing fishery area for adult eels. Japanese eels are distributed in the main rivers and many tributaries from the Yangtze River estuary to the upper Jinsha River, which extend to nearly 3 000 km. However, their migration behaviors remain relatively unknown. We analyzed the biological characteristics of 153 specimens of silver eels collected from the Jingjiang section of Yangtze River (31(o)30'N, 120(o)42'E) between September and November, 2008, and tested the sagittal Sr/Ca ratios of 27 specimens. Among the 153 specimens examined, 85 were female and 68 were male, which translated to a female-male ratio of 1 : 0.8. The ages of the female specimens ranged from 3 to 7 a (average 5.52) with an average total length (TL) of (669 ± 80) mm, average body weight (BW) of (555 ± 229)g, average condition factor of 1.77 ± 0.22, and average gonad somatic index (GSI) of 1.32 ± 0.31. The ages of the males ranged from 3 to 5 a (average:4.38) with an average TL of (518 ± 51) mm, average BW of (234 ± 76) g, average condition factor of 1.62 ± 0.18, and average GSI of 0.21 ± 0.11. All biological parameters of females were significantly larger than those of the male specimens (P<0.05). According to the average Sr/Ca ratio (7.99 ± 1.05) × 10(-3) of the elver mark of sagitta, 17 individuals (62.96%) were river eels and 10 individuals (37.04%) were estuarine eels. Of 16 females, 13 individuals (81.25%) were river eels and 3 were estuarine eels, while of 11 males, 36.36% were river eels and 63.64% were estuarine eels. The analysis on Sr/Ca ratios for every growth layer group (GLG) indicated there were no significant differences between second-age males and females. However, significant differences were observed between the third-age, fourth-age, and migration-age male and female specimens. This was likely related to the fact that second-age eels of both sexes stay in the same inhabitation waters; however, as they grow older, they move to different areas.

Circulating secretory type IIA phospholipase A2, lipoprotein (a) and soluble cellular adhesion molecule levels in patients with angina pectoris.

OBJECTIVES: To examine the plasma levels of secretory type IIA phospholipase A2 (sPLA(2)-IIA), lipoprotein (a) [Lp(a)], soluble intercellular adhesion molecule-1 (sICAM-1) and soluble platelet endothelial CAM-1 (sPECAM-1), as well as ICAM-1 (K469E) and PECAM-1 (Leu125Val) gene polymorphisms, in patients with unstable angina pectoris (UAP) and stable AP (SAP). DESIGN AND METHODS: We enrolled 75 patients with SAP, 72 with UAP and 80 controls without angina. Blood samples were obtained before angiography. RESULTS: The concentrations of sPLA(2)-IIA, sICAM-1 and sPECAM-1 were higher for UAP patients than for SAP patients and controls, and the level of Lp(a) was higher for UAP patients than for controls. Lp(a) and sPLA(2)-IIA levels were significantly correlated, and high plasma Lp(a) level (> or =300 mg/L) was an independent risk factor for angina. CONCLUSION: Lp(a) may play an important role in the development of angina. Further research should investigate the role of sPLA(2)-IIA, sICAM-1 and sPECAM-1 in UAP.