Exploring auditory temporal resolution and dichotic listening skills among individuals with type 2 diabetes mellitus.

The study aimed to explore the auditory temporal resolution and dichotic listening skills in patients with type 2 diabetes mellitus (T2DM) and identify associated health-related factors. Using a cross-sectional design, 87 adults with T2DM and 48 non-diabetic controls, all with normal hearing, participated. The two central auditory processing (CAP) skills were assessed through the Gaps-In-Noise (GIN) and Dichotic-Digits Listening (DDL) tests. T2DM participants underwent blood tests to measure various health-related factors. In the GIN test, the shortest gap threshold (GapTh) obtained across both ears was significantly higher in the diabetic group (9.1 ± 2.4 ms) compared to the non-diabetic group (7.5 ± 1.5 ms), and the score of correctly identified gaps (GapSc) in the diabetic group (45±11 %) was significantly lower than GapSc in the non-diabetic group (52±9 %), p < 0.001. In the DDL test, the free-recall score (73.8 ± 18.5 %) across both ears and the right-ear advantage (-1.3 ± 20.6 %) in the diabetic group were significantly lower than the free-recall score (85.8 ± 11.9 %) and right-ear advantage (6.9 ± 11.9 %) in the non-diabetic group, p < 0.005. Furthermore, the duration of diabetes, eGFR level, retinopathy, carotid plaque, fasting blood glucose level, and HDL-C (good cholesterol) level were factors significantly associated with performances in the GIN and/or DDL tests for T2DM participants. In conclusion, individuals with T2DM are at risk of reduced auditory processing skills in temporal resolution and dichotic listening, impacting their speech understanding. Six health-related factors were identified as significantly associated with CAP skills in T2DM patients.

Plant-derived extracellular vesicles as a promising anti-tumor approach: A comprehensive assessment of effectiveness, safety, and mechanisms.

BACKGROUND: Plant-derived extracellular vesicles (PDEs) are expected to be a compelling alternative for cancer treatment due to their low cytotoxicity, low immunogenicity, high yield, and potential anti-tumor efficacy. Despite the significant advantages of PDEs, the reliable evidence for PDEs as promising anti-tumor approach remains unsystematic and insufficient. Some challenges remain for the clinical application and large-scale industrial production of PDEs. PURPOSE: Through systematic evaluation and meta-analysis, the objective was to provide scientific, systematic and reliable preclinical evidence to support the clinical use of PDEs in cancer therapy. METHODS: The search for relevant literature, conducted up to March 2024, encompassed various databases including Web of Science, the Cochrane Library, Embase, PubMed, CNKI, Wanfang Data, and the China Science and Technology Journal Database. The SYRCLE´s risk of bias tool was used to assess the methodological quality of the animal studies. For overall effect analysis and subgroup analysis, RevMan 5.4 and Stata 12.0 were utilized. RESULTS: The analysis incorporated a total of 38 articles, comprising 29 in vivo studies and 9 in vitro studies. Meta-analysis indicated that PDEs significantly reduced cancer cell activity and induced apoptosis, reduced tumor volume and tumor weight when used as therapeutic agents, as well as exhibited synergistic anti-cancer via combination therapy. Additionally, PDEs-drugs exerted stronger inhibition of tumor volume compared to the free drug or commercial liposome-drugs. Their therapeutic effects were closely related to regulating tumor cell biological behavior and remodeling the tumor microenvironment. The safety was associated with administration route of PDEs, oral administration was currently preferred until more in-depth studies on the safety of other methods are conducted. CONCLUSIONS: The meta-analysis revealed that PDEs have systematic and reliable preclinical evidence in preclinical studies of cancer therapy, and their efficacy and certain safety could support the clinical application of PDEs in cancer therapy. Of course, further researches are required for large-scale industrial production to meet the needs of clinical applications.

The Effects of Dietary n-3 Highly Unsaturated Fatty Acids on Growth, Antioxidant Capacity, Immunity, and Oxylipin Profiles in Acipenser dabryanus.

Currently, the effects of dietary levels of n-3 highly unsaturated fatty acids (HUFAs) on the growth performance, antioxidant capacity, immunity, and serum oxylipin profiles of female F2-generation Yangtze sturgeon remain unknown. A total of 75 Yangtze sturgeons, an endangered freshwater fish species, with an average body weight of 3.60 ± 0.83 kg, were randomly allocated to 15 concrete pools, with each dietary group represented by 5 fish per pool. The fish were fed five different experimental diets containing various levels of n-3 HUFAs (0.5%, 1.0%, 1.5%, 2.0%, and 2.4%). After a feeding period of 5 months, no significant differences in the growth performances of the fish were observed among the five dietary groups (p > 0.05). However, we did note that the serum levels of low-density lipoprotein cholesterol (LDL-C), triglycerides (TGs), and total cholesterol (TCHO) exhibited a marked increase in the fish that consumed higher dietary n-3 HUFA levels (p < 0.05). Conversely, alkaline phosphatase (ALP) activities showed a notable decrease as dietary n-3 HUFA levels increased (p < 0.05). Serum antioxidant indices, such as the activity levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), were significantly higher in the 2.4% HUFA group compared to the 0.5% HUFA group. Additionally, muscle antioxidant indices, including total antioxidant capacity (T-AOC), catalase (CAT), and SOD activity, exhibited notable increases as dietary n-3 HUFA levels increased (p < 0.05). Furthermore, there was a decrease in malondialdehyde (MDA) levels as dietary n-3 HUFA levels increased (p < 0.05). In relation to immune indices, only serum immunoglobulin M (IgM) and muscle complement 3 (C3) were found to be influenced by dietary n-3 HUFA levels (p < 0.05). A total of 80 oxylipins were quantified, and our subsequent K-means cluster analysis resulted in the classification of 62 oxylipins into 10 subclasses. Among the different n-3 HUFA diets, a total of 14 differential oxylipins were identified in the sera. These findings demonstrate that dietary supplementation with n-3 HUFAs exceeding a 1.0% level can enhance antioxidant capacity and regulate serum lipid metabolism, potentially through modulation of oxylipins derived from ARA, DHA, and EPA. These insights provide novel perspectives on the mechanisms underlying these observations.

RGBT Tracking via Challenge-Based Appearance Disentanglement and Interaction.

RGB and thermal source data suffer from both shared and specific challenges, and how to explore and exploit them plays a critical role in representing the target appearance in RGBT tracking. In this paper, we propose a novel approach, which performs target appearance representation disentanglement and interaction via both modality-shared and modality-specific challenge attributes, for robust RGBT tracking. In particular, we disentangle the target appearance representations via five challenge-based branches with different structures according to their properties, including three parameter-shared branches to model modality-shared challenges and two parameter-independent branches to model modality-specific challenges. Considering the complementary advantages between modality-specific cues, we propose a guidance interaction module to transfer discriminative features from one modality to another one to enhance the discriminative ability of weak modality. Moreover, we design an aggregation interaction module to combine all challenge-based target representations, which could form more discriminative target representations and fit the challenge-agnostic tracking process. These challenge-based branches are able to model the target appearance under certain challenges so that the target representations can be learned by a few parameters even in the situation of insufficient training data. In addition, to relieve labor costs and avoid label ambiguity, we design a generation strategy to generate training data with different challenge attributes. Comprehensive experiments demonstrate the superiority of the proposed tracker against the state-of-the-art methods on four benchmark datasets.

Comparative Transcriptome Analysis Reveals Sexually Dimorphic Gene Expression in the Gonads of Brachymystax tsinlingensis Li.

Brachymystax tsinlingensis Li is an endangered cold-water salmonid fish native to China. This study aimed to identify sex-related genes and biological pathways via gonadal transcriptome sequencing of B. tsinlingensis Li. A total of 167,904 unigenes were identified with an average length of 836 bp and an N50 of 1452 bp, of which 84,977 (50.61%) unigenes were successfully annotated in six major databases. Comparative transcriptome analysis identified 22,864 differentially expressed genes (DEGs), of which 17,231 were up-regulated (male-biased genes, mDEGs) and 5633 were down-regulated (female-biased genes, fDEGs). Several DEGs associated with gonadal development were found through Gene Ontology enrichment analysis, such as ccnb1, zp3, bmp15, dmrt1, and psmc3ip. Signaling pathways related to gonadal development were found to be enriched through analysis using the Kyoto Encyclopedia of Genes and Genomes Pathway database, such as genes involves in base excision repair, the notch signaling pathway, neuroactive ligand-receptor interaction, the VEGF signaling pathway, and the estrogen signaling pathway. In addition, mRNA expression levels of 19 DEGs were determined to validate the reliability of the transcriptomic data by quantitative real-time polymerase chain reaction. These results revealed genes and signaling pathways potentially involved in gonadal development in B. tsinlingensis Li and provided basic molecular data for future research on reproductive regulation and breeding of B. tsinlingensis Li.

Chromosome-level genome assembly of the largefin longbarbel catfish (Hemibagrus macropterus).

The largefin longbarbel catfish, Hemibagrus macropterus, is an economically important fish species in southwestern China, with males growing faster than females. This study presents a high-quality chromosome-level genome assembly of the largefin longbarbel catfish, generated by integrating Illumina short reads, PacBio HiFi long reads, and Hi-C data. The assembled genome size was 858.5 Mb, with a contig and scaffold N50 of 5.8 Mb and 28.4 Mb, respectively. A total of 656 contigs were successfully anchored to 30 pseudochromosomes with a BUSCO score of 97.7%, consistent with the number of chromosomes analyzed by karyotype. The genome contained 29.5% repeat sequences, and a predicted total of 26,613 protein-coding genes, of which 25,769 (96.8%) were functionally annotated in different databases. Evolutionary analysis showed that H. macropterus was most closely related to H. wyckioides, with a divergence time of approximately 16.3 million years. Chromosomal syntenic relationships among H. macropterus, H. wyckioides, and Pelteobagrus fulvidraco revealed a one-to-one relationship for most chromosomes, except for break, fission, and inversion of some chromosomes. The first high-quality reference genome will not only provide a valuable genetic resource for the study of sex determination mechanisms and genetic breeding of largefin longbarbel catfish, but also contribute to comparative analyses of genome and chromosome evolution within Siluriformes.

Transcriptome Analyses Reveal Expression Profiles of Morphologically Undifferentiated and Differentiated Gonads of Yangtze Sturgeon Acipenser dabryanus.

Sturgeon is known as a primitive fish with the ZZ/ZW sex determination system and is highly prized for its valuable caviar. Exploring the molecular mechanisms underlying gonadal differentiation would contribute to broadening our knowledge on the genetic regulation of sex differentiation of fish, enabling improved artificial breeding and management of sturgeons. However, the mechanisms are still poorly understood in sturgeons. This study aimed to profile expression patterns between female and male gonads at morphologically undifferentiated and early differentiated stages and identify vital genes involved in gonadal sex differentiation of sturgeons. The sexes of Yangtze sturgeon (Acipenser dabryanus) juveniles were identified via the sex-specific DNA marker and histological observation. Transcriptome analyses were carried out on female and male gonads at 30, 80 and 180 days post-hatching. The results showed that there was a total of 17 overlapped DEGs in the comparison groups of between female and male gonads at the three developmental stages, in which there were three DEGs related to ovarian steroidogenesis, including hsd17b1, foxl2 and cyp19a1. The three DEGs were highly expressed in the female gonads, of which the expression levels were gradually increased with the number of days after hatching. No well-known testis-related genes were found in the overlapped DEGs. Additionally, the expression levels of hsd17b1 and cyp19a1 mRNA were decreased with the knockdown of foxl2 mRNA via siRNA. The results further suggested that foxl2 should play a crucial role in the ovarian differentiation of sturgeons. In conclusion, this study showed that more genes involved in ovarian development than testis development emerged with sexually dimorphic expression during early gonadal sex differentiation, and it provided a preliminary understanding of the molecular regulation on gonadal differentiation of sturgeons.

Dietary Epigallocatechin-3-Gallate (EGCG) Improves Nonspecific Immune Response of Chinese Rice Field Eel (Monopterus albus).

Epigallocatechin-3-gallate (EGCG) has been recognized as a potential additive for aquafeeds due to its beneficial biological functions. In order to evaluate the potential application of EGCG in Chinese rice field eel (Monopterus albus), six isonitrogenous and isolipidic diets containing 0, 25, 50, 100, 200, and 400 mg/kg EGCG were formulated and were fed to Monopterus albus (M. albus) for 9 weeks. The results showed that M. albus fed diets containing 0 and 100 mg/kg EGCG presented higher weight again and specific growth rate than the other groups. Fish fed with 25, 50, and 400 mg/kg EGCG displayed lower whole-body lipid content. Serum aspartate aminotransferase (AST) concentration significantly decreased in EGCG treated groups with the exception of 100 mg/kg group. Hepatic catalase (CAT) activity and glutathione (GSH) concentration decreased as EGCG level increased while malondialdehyde (MDA) concentration showed an opposite trend. EGCG supplementation resulted in a promoted lysozyme (LZM) activity and immunoglobulin M (IgM) level in the liver of M. albus. Furthermore, transcription of three immune related genes including major histocompatibility complex (mhc-2α), hepcidin, and interleukin-8 (il-8) mRNAs was upregulated by EGCG treatment; while transcription of interleukin-6 (il-6) and nuclear factor kappa-B (nf-kb) genes was downregulated. Results also showed a linear relation between EGCG inclusion level and parameters of AST, CAT, GSH, MDA, LZM, IgM, and immune-related genes transcriptions. In summary, it could be suggested that EGCG supplementation enhanced the nonspecific immune response of the Chinese rice field eel. Based on the broken-line regression analysis of IgM, the optimal dietary EGCG supplementation for M. albus was estimated to be 109.81 mg/kg.

Co-delivery of minoxidil and tocopherol acetate ethosomes to reshape the hair Follicular Microenvironment and promote hair regeneration in androgenetic alopecia.

The most prevalent kind of hair loss is androgenic alopecia (AGA), which is characterized by hair follicle miniaturization and microenvironment dysfunction. Although topical Minoxidil (MXD) was considered to be a safe and effective treatment for AGA, excess reactive oxygen species (ROS) and lower sulfotransferase activity in the hair follicular microenvironment led to an unsatisfactory treatment of AGA. Here, we developed the ethosome (MTE) load of minoxidil and tocopherol acetate to improve the therapeutic effect of MXD on androgenic alopecia. It could regulate the microenvironment around hair follicles, promote the telogen-to-anagen transition of hair follicles, and boost hair regeneration, thus achieving a synergistic effect of 1 + 1 > 2. The results proved that MTE showed excellent stability, biosafety, and good dermal and follicular permeability in vitro. The hair regeneration ability of AGA model mice showed that the co-delivery ethosome might regulate the microenvironment around the hair follicles and improve hair regeneration in comparison to the commercial minoxidil tincture alone. As a result, the strategy provided a promising new strategy for the treatment of AGA.

Silane-modified hydroxyapatite nanoparticles incorporated into polydioxanone/poly(lactide-co-caprolactone) creates a novel toughened nanocomposite with improved material properties and in vivo inflammatory responses.

The interface tissue between bone and soft tissues, such as tendon and ligament (TL), is highly prone to injury. Although different biomaterials have been developed for TL regeneration, few address the challenges of the TL-bone interface. Here, we aim to develop novel hybrid nanocomposites based on poly(p-dioxanone) (PDO), poly(lactide-co-caprolactone) (LCL), and hydroxyapatite (HA) nanoparticles suitable for TL-bone interface repair. Nanocomposites, containing 3-10% of both unmodified and chemically modified hydroxyapatite (mHA) with a silane coupling agent. We then explored biocompatibility through in vitro and in vivo studies using a subcutaneous mouse model. Through different characterisation tests, we found that mHA increases tensile properties, creates rougher surfaces, and reduces crystallinity and hydrophilicity. Morphological observations indicate that mHA nanoparticles are attracted by PDO rather than LCL phase, resulting in a higher degradation rate for mHA group. We found that adding the 5% of nanoparticles gives a balance between the properties. In vitro experiments show that osteoblasts' activities are more affected by increasing the nanoparticle content compared with fibroblasts. Animal studies indicate that both HA and mHA nanoparticles (10%) can reduce the expression of pro-inflammatory cytokines after six weeks of implantation. In summary, this work highlights the potential of PDO/LCL/HA nanocomposites as an excellent biomaterial for TL-bone interface tissue engineering applications.

Investigation of Broadband Optical Nonlinear Absorption and Transient Dynamics in Orange IV Containing Azobenzene.

Broadband reverse saturable absorption is systematically investigated via Z-scan, transient absorption spectrum (TAS). The excited state absorption and negative refraction of Orange IV are observed in the Z-scan experiment at 532 nm. Meanwhile, two-photon-induced excited state absorption and pure two-photon absorption are observed at 600 nm and 700 nm with the pulse width of 190 fs, respectively. An ultrafast broadband absorption in the visible wavelength region is observed via TAS. The different nonlinear absorption mechanisms at multiple wavelengths are discussed and interpreted from the results of TAS. In addition, the ultrafast dynamics of negative refraction in the excited state of Orange IV are investigated via a degenerate phase object pump-probe, from which the weak long-lived excited state is extracted. All studies indicate that Orange IV has the potential to be further optimized into a superior broadband reverse saturable absorption material and also has certain reference significance for the study of optical nonlinearity in organic molecules containing azobenzene groups.

Selective Delivery of Tofacitinib Citrate to Hair Follicles Using Lipid-Coated Calcium Carbonate Nanocarrier Controls Chemotherapy-Induced Alopecia Areata.

Chemotherapy-induced alopecia (CIA) is one of the common side effects in cancer treatment. The psychological distress caused by hair loss may cause patients to discontinue chemotherapy, affecting the efficacy of the treatment. The JAK inhibitor, Tofacitinib citrate (TFC), showed huge potential in therapeutic applications for treating baldness, but the systemic adverse effects of oral administration and low absorption rate at the target site limited its widespread application in alopecia. To overcome these problems, we designed phospholipid-calcium carbonate hybrid nanoparticles (PL/ACC NPs) for a topical application to target deliver TFC. The results proved that PL/ACC-TFC NPs showed excellent pH sensitivity and transdermal penetration in vitro. PL/ACC NPs offered an efficient follicular targeting approach to deliver TFC in a Cyclophosphamide (CYP)-induced alopecia areata mouse model. Compared to the topical application of TFC solution, PL/ACC-TFC NPs significantly inhibited apoptosis of mouse hair follicles and accelerated hair growth. These findings support that PL/ACC-TFC NPs has the potential for topical application in preventing and mitigating CYP-induced Alopecia areata.

Systematic evaluation of three porcine-derived collagen membranes for guided bone regeneration.

Guided bone regeneration is one of the most common surgical treatment modalities performed when an additional alveolar bone is required to stabilize dental implants in partially and fully edentulous patients. The addition of a barrier membrane prevents non-osteogenic tissue invasion into the bone cavity, which is key to the success of guided bone regeneration. Barrier membranes can be broadly classified as non-resorbable or resorbable. In contrast to non-resorbable membranes, resorbable barrier membranes do not require a second surgical procedure for membrane removal. Commercially available resorbable barrier membranes are either synthetically manufactured or derived from xenogeneic collagen. Although collagen barrier membranes have become increasingly popular amongst clinicians, largely due to their superior handling qualities compared to other commercially available barrier membranes, there have been no studies to date that have compared commercially available porcine-derived collagen membranes with respect to surface topography, collagen fibril structure, physical barrier property, and immunogenic composition. This study evaluated three commercially available non-crosslinked porcine-derived collagen membranes (Striate+TM, Bio-Gide® and CreosTM Xenoprotect). Scanning electron microscopy revealed similar collagen fibril distribution on both the rough and smooth sides of the membranes as well as the similar diameters of collagen fibrils. However, D-periodicity of the fibrillar collagen is significantly different among the membranes, with Striate+TM membrane having the closest D-periodicity to native collagen I. This suggests that there is less deformation of collagen during manufacturing process. All collagen membranes showed superior barrier property evidenced by blocking 0.2-16.4 µm beads passing through the membranes. To examine the immunogenic agents in these membranes, we examined the membranes for the presence of DNA and alpha-gal by immunohistochemistry. No alpha-gal or DNA was detected in any membranes. However, using a more sensitive detection method (real-time polymerase chain reaction), a relatively strong DNA signal was detected in Bio-Gide® membrane, but not Striate+TM and CreosTM Xenoprotect membranes. Our study concluded that these membranes are similar but not identical, probably due to the different ages and sources of porcine tissues, as well as different manufacturing processes. We recommend further studies to understand the clinical implications of these findings.

Additively manufactured polyethylene terephthalate scaffolds for scapholunate interosseous ligament reconstruction.

The regeneration of the ruptured scapholunate interosseous ligament (SLIL) represents a clinical challenge. Here, we propose the use of a Bone-Ligament-Bone (BLB) 3D-printed polyethylene terephthalate (PET) scaffold for achieving mechanical stabilisation of the scaphoid and lunate following SLIL rupture. The BLB scaffold featured two bone compartments bridged by aligned fibres (ligament compartment) mimicking the architecture of the native tissue. The scaffold presented tensile stiffness in the range of 260 ± 38 N/mm and ultimate load of 113 ± 13 N, which would support physiological loading. A finite element analysis (FEA), using inverse finite element analysis (iFEA) for material property identification, showed an adequate fit between simulation and experimental data. The scaffold was then biofunctionalized using two different methods: injected with a Gelatin Methacryloyl solution containing human mesenchymal stem cell spheroids (hMSC) or seeded with tendon-derived stem cells (TDSC) and placed in a bioreactor to undergo cyclic deformation. The first approach demonstrated high cell viability, as cells migrated out of the spheroid and colonised the interstitial space of the scaffold. These cells adopted an elongated morphology suggesting the internal architecture of the scaffold exerted topographical guidance. The second method demonstrated the high resilience of the scaffold to cyclic deformation and the secretion of a fibroblastic related protein was enhanced by the mechanical stimulation. This process promoted the expression of relevant proteins, such as Tenomodulin (TNMD), indicating mechanical stimulation may enhance cell differentiation and be useful prior to surgical implantation. In conclusion, the PET scaffold presented several promising characteristics for the immediate mechanical stabilisation of disassociated scaphoid and lunate and, in the longer-term, the regeneration of the ruptured SLIL.

Novel hybrid biocomposites for tendon grafts: The addition of silk to polydioxanone and poly(lactide-co-caprolactone) enhances material properties, in vitro and in vivo biocompatibility.

Biopolymers play a critical role as scaffolds used in tendon and ligament (TL) regeneration. Although advanced biopolymer materials have been proposed with optimised mechanical properties, biocompatibility, degradation, and processability, it is still challenging to find the right balance between these properties. Here, we aim to develop novel hybrid biocomposites based on poly(p-dioxanone) (PDO), poly(lactide-co-caprolactone) (LCL) and silk to produce high-performance grafts suitable for TL tissue repair. Biocomposites containing 1-15% of silk were studied through a range of characterisation techniques. We then explored biocompatibility through in vitro and in vivo studies using a mouse model. We found that adding up to 5% silk increases the tensile properties, degradation rate and miscibility between PDO and LCL phases without agglomeration of silk inside the composites. Furthermore, addition of silk increases surface roughness and hydrophilicity. In vitro experiments show that the silk improved attachment of tendon-derived stem cells and proliferation over 72 h, while in vivo studies indicate that the silk can reduce the expression of pro-inflammatory cytokines after six weeks of implantation. Finally, we selected a promising biocomposite and created a prototype TL graft based on extruded fibres. We found that the tensile properties of both individual fibres and braided grafts could be suitable for anterior cruciate ligament (ACL) repair applications.

Natural, synthetic and commercially-available biopolymers used to regenerate tendons and ligaments.

Tendon and ligament (TL) injuries affect millions of people annually. Biopolymers play a significant role in TL tissue repair, whether the treatment relies on tissue engineering strategies or using artificial tendon grafts. The biopolymer governs the mechanical properties, biocompatibility, degradation, and fabrication method of the TL scaffold. Many natural, synthetic and hybrid biopolymers have been studied in TL regeneration, often combined with therapeutic agents and minerals to engineer novel scaffold systems. However, most of the advanced biopolymers have not advanced to clinical use yet. Here, we aim to review recent biopolymers and discuss their features for TL tissue engineering. After introducing the properties of the native tissue, we discuss different types of natural, synthetic and hybrid biopolymers used in TL tissue engineering. Then, we review biopolymers used in commercial absorbable and non-absorbable TL grafts. Finally, we explain the challenges and future directions for the development of novel biopolymers in TL regenerative treatment.

The last giants of the Yangtze River: A multidisciplinary picture of what remains of the endemic Chinese sturgeon.

The Chinese sturgeon, an important endemism of the Yangtze River, belongs to 'the most critically endangered group of species' worldwide, with overfishing and habitat destruction being the main drivers towards extinction. Newly obtained microchemical comparisons between animals and water from different river locations revealed a probable shifting of the spawning ground few kilometers downstream compared to the only previously known site, located under the Gezhouba Dam. This offers a glimmer of hope for an adaptive response to habitat perturbation caused by the recently built Three Gorges dam on the Yangtze River. On the other hand, genetic data provide an estimate of about 20 breeders participating in the only significant breeding event of the past 10 years. This warns of a near species extinction forecast if no in situ and ex situ conservation efforts occur promptly. Given these results we propose a list of priority conservation actions that urgently need to be promoted, supported, and put into practice.

Spermatogonia From Cryopreserved Testes of Critically Endangered Chinese Sturgeon Efficiently Colonized and Preferentially Proliferated in the Recipient Gonads of Yangtze Sturgeon.

The critically endangered Chinese sturgeon, Acipenser sinensis, presents late sexual maturity and has a large body size. Germ cell transplantation is a powerful technique for the production of gametes from large-bodied species in closely related recipients with a smaller body size and shorter generation time. To accelerate reproduction of Chinese sturgeon, donor spermatogonia collected from the cryopreserved testes of 3-year-old Chinese sturgeon were intraperitoneally transplanted into 7-8 days post-hatch larvae of Yangtze sturgeon (Acipenser dabryanus) with shorter generation interval. At 2 months post-transplantation (mpt), donor spermatogonia had colonized in the 81.25% of recipient gonads, with average numbers about two times those of endogenous primordial germ cells. Within the next 2 months, the rate of endogenous germ cell division in females (2-3 times) was faster than that in males (once), whereas colonized donor-derived spermatogonia divided about 2-3 times and twice in recipient females and males, respectively. Furthermore, the expression of germ cell-related genes, dazl, dead end, and vasa, in transplanted fish was higher than that in non-transplanted fish, suggesting the incorporation and proliferation donor spermatogonia in recipient. At 18 mpt, donor-derived spermatogonia survived in the 75.00% of recipient gonads. These results showed that the somatic microenvironment of Yangtze sturgeon gonad can support the long-term colonization, proliferation, and survival of xenogeneic germ cells. Thus, this study suggested that small-bodied Yangtze sturgeon is promising recipient as surrogate for Chinese sturgeon gamete production.

In Vitro 3D Mechanical Stimulation to Tendon-Derived Stem Cells by Bioreactor.

Bioreactors can offer an advanced platform to provide conditions that mimic the native microenvironment, which can also provide stretching environment for mechanobiology research. Tendon-derived stem cells (TDSCs) are a type of mechanosensitive and multipotent cells, which behave differently in diverse mechanical stretching environments. We have proved the in vitro three-dimensional (3D) mechanical stimulation could closely mimic the stretching environment in vivo. Thus, here we describe applying a customized bioreactor to provide 3D force for mechanical stimulation on TDSC in vitro.

Screening and identification of female-specific DNA sequences in octaploid sturgeon using comparative genomics with high-throughput sequencing.

In this study, six candidate female-specific DNA sequences of octaploid Amur sturgeon (Acipenser schrenckii) were identified using comparative genomic approaches with high-throughput sequencing data. Their specificity was confirmed by traditional PCR. Two of these sex-specific sequences were also validated as female-specific in other eight sturgeon species and two hybrid sturgeons. The identified female-specific DNA fragments suggest that the family Acipenseridae has a ZZ/ZW sex-determining system. However, one of the two DNA sequences has been deleted in some sturgeons such as Sterlet sturgeon (Acipenser ruthenus), Beluga (Huso huso) and Kaluga (H. dauricus). The difference of sex-specific sequences among sturgeons indicates that there are different sex-specific regions among species of sturgeon. This study not only provided the sex-specific DNA sequences for management, conservation and studies of sex-determination mechanisms in sturgeons, but also confirmed the capability of the workflow to identify sex-specific DNA sequences in the polyploid species with complex genomes.