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The skin microbiota plays an essential role in helping the host adapt to different environments and maintain health. By examining the characteristics of amphibian skin flora alongside ontogenetic traits, we can gain insights into the adaptation mechanisms of amphibian skin flora to environmental changes during development. In this study, we analyzed the skin microbiota of Quasipaa spinosa during metamorphosis using Illumina sequencing. Venn diagrams and UpSet analysis revealed that the LTS (hindlimb tadpoles’ skin, aquatic habitat) and FTS (forelimb tadpoles’ skin, shift from aquatic to amphibious habitats) groups exhibited a higher number of unique amplicon sequence variants (ASVs), while the TS (tadpoles’ skin, aquatic habitat) and LFS (land frogs’ skin, amphibious habitats) groups displayed a lower abundance of ASVs. Diversity analysis indicated similarities in the microorganisms between the LTS and the FTS groups, with higher microbial diversity compared to the TS and the LFS groups. Additionally, microbial co-occurrence network analysis indicated a more stable microecology in the LTS group and FTS group. Proteobacteria, Firmicutes, and Bacteroidota were identified as the dominant phyla, although their relative abundances varied widely among groups. LEfSe (Linear discriminant analysis effect size) showed significant enrichment of beneficial bacteria at various developmental stages, including Bacteroides, Bacillus, and Lactobacillus. Functional prediction analysis shows significant differences in skin microorganism functions across various developmental stages, with a primary focus on metabolic functions. This study provides valuable insights into the compositional dynamics of skin microbiota in Q. spinosa at various developmental stages.

Chinese soft-shelled turtle (Pelodiscus sinensis) is an important aquaculture species in China. However, with the continuous development of P. sinensis cultures, problems related to germplasm degradation and population mixing have become increasingly prominent. This has seriously affected the protection and utilization of germplasm resources by P. sinensis. To broaden the understanding of the germplasm resources of P. sinensis and improve the efficiency of germplasm identification, Super-GBS sequencing technology was used to conduct population genetic analysis of P. sinensis samples from six different populations distributed in five provinces. As a result, 1464,488 SNPs were identified. Genetic structure analysis revealed that the six P. sinensis populations could be divided into three sub-populations. The genetic differentiation coefficient of the DT and CY populations was very low (Fst=0.0088), indicating that differentiation had not yet occurred. Additionally, 15 KASP core markers for the identification of P. sinensis populations were developed using KASP typing technique for the first time. Genetic information can lay a foundation for the protection and utilization of germplasm resources by P. sinensis, and the fingerprinting database developed in this study provides a practical tool for authenticating P. sinensis.

Titanium oxides (TiO2) nanostructures coating is helpful in improving the utilization of titanium in many areas due to its multifunctional properties. This study introduces a novel approach for the in-situ fabrication of nano cones-like structures of rutile titanium oxides (NCS–TiO2) on the surface of titanium utilizing femtosecond laser technology. Rutile titanium oxides were synthesized with a height of around 80 nm and a diameter of 100 nm, forming NCS that imparts higher hardness, wear resistance, and biocompatibility. Molecular dynamic simulation provides valuable insights into the three-stage formation process of NCS-TiO2. Molecular dynamic simulation revealed that the growth of rutile titanium oxides and the formation of nano cones-like structures are attributed to the interplay between femtosecond laser ablation and the accumulation of thermal energy. The proposed method offers a versatile and straightforward approach for creating functional surfaces on metal substrates, enabling broad applicability and ease of implementation, specifically in titanium and its alloys. This advancement holds great potential for expanding the scope of titanium-based materials and their applications, paving the way for improved mechanical properties and biocompatibility in diverse fields.

Cnidarians are among the most important diploblastic organisms, elucidating many of the early stages of Metazoan evolution. However, Cnidarian fossils from Cambrian deposits have been rarely documented, mainly due to difficulties in identifying early Cnidarian representatives. Halysites, a tabulate coral from Silurian reef systems, serves as a crucial taxon for interpreting Cambrian cnidarians. Traditionally, the biological characteristics of Halysites have been analyzed using methods limited by pretreatment requirements (destructive testing) and the chamber size capacity of relevant analytical instruments. These constraints often lead to irreversible information loss and inadequate data extraction. This means that, to date, there has been no high-resolution three-dimensional mineralization analysis of Halysites. This study aims to introduce novel, non-destructive techniques to analyze the internal structure and chemical composition of Halysites. Furthermore, it seeks to elucidate the relationship between coral organisms and biomineralization in reef settings and to compare Silurian Tabulata with putative Cambrian cnidarians. Techniques such as micro-X-ray fluorescence spectrometry (micro-XRF), micro-X-ray computed tomography (micro-CT), and scanning electron microscopy (SEM) were employed in this research. With the help of high-resolution micro-CT scanning, we identify the growth pattern of Halysites, showing both lateral and vertical development. The lateral multiple-branching growth pattern of Halysites corals is first established herein. The flaggy corallite at the initial stage of branching is also observed. The micro-XRF mapping results reveal the occurrence of septa spines for Halysites, a trait previously thought rare or absent. Additionally, the ratio of coral volume to the surrounding rock was assessed, revealing that Halysites reefs were relatively sparse (volume ratio = ~30%). The cavities between Halysites likely provided more space for other organisms (e.g., rugose corals and bryozoans) when compared to other coral reef types. Additionally, we provide a comparative analysis of post-Cambrian colonial calcareous skeletons, offering insights into the structural features and growth patterns of early skeletal metazoans across the Ediacaran–Cambrian boundary.

The Chinese soft-shelled turtle (Pelodiscus sinensis) has become increasingly susceptible to frequent diseases with the intensification of farming, which severely impacts the development of the aquaculture industry. Sodium butyrate (SB) is widely used as a feed additive due to its promotion of growth, enhancement of immune function, and antioxidative properties. This study aimed to investigate the effects of dietary SB on the growth performance, immune function, and intestinal microflora of Chinese soft-shelled turtles. A total of 300 Chinese soft-shelled turtles (mean weight: 11.36 ± 0.21g) were randomly divided into four groups with three parallel sets in each group. Each group was fed a diet supplemented with 0%, 0.005%, 0.01%, or 0.02% SB for 60 days. The results demonstrated an upward trend in weight gain rate (WGR) and specific growth rate (SGR) with increasing SB supplementation, and the experimental group fed with 0.02% SB showed a significant increase in WGR and SGR compared to other groups (P< 0.05). These levels of SB also decreased the levels of feed conversion ratio (FCR) and the total cholesterol (TC) content of Chinese soft-shelled turtles, and the 0.02% SB was significantly lower than that of other groups (P< 0.05). The activity of complement protein in vivo increased with increases in SB content, and the activities of complement C3 and C4 reached the highest level with 0.02% SB. The species abundance of the experimental group D fed with 0.02% SB was significantly higher than that of other groups (P< 0.05). Furthermore, the relative abundance of Clostridium sensu stricto 1 was significantly increased with 0.02% SB (P< 0.05). In conclusion, adding 0.02% SB to the diet improves the growth performance, feed digestion ability, and intestinal microbiota of Chinese soft-shelled turtles.

Abstract Background Aquatic animals show diverse body coloration, and the formation of animal body colour is a complicated process. Increasing evidence has shown that microRNAs (miRNAs) play important regulatory roles in many life processes. The role of miRNAs in pigmentation has been investigated in some species. However, the regulatory patterns of miRNAs in reptile pigmentation remain to be elucidated. In this study, we performed an integrated analysis of miRNA and mRNA expression profiles to explore corresponding regulatory patterns in embryonic body colour formation in the soft-shelled turtle Pelodiscus sinensis. Results We identified 8 866 novel genes and 9 061 mature miRNAs in the skin of Chinese soft-shelled turtles in three embryonic stages (initial period: IP, middle period: MP, final period: FP). A total of 16 563 target genes of the miRNAs were identified. Furthermore, we identified 2 867, 1 840 and 4 290 different expression genes (DEGs) and 227, 158 and 678 different expression miRNAs (DEMs) in IP vs. MP, MP vs. FP, and IP vs. FP, respectively. Among which 72 genes and 25 miRNAs may be related to turtle pigmentation in embryonic development. Further analysis of the novel miRNA families revealed that some novel miRNAs related to pigmentation belong to the miR-7386, miR-138, miR-19 and miR-129 families. Novel_miR_2622 and novel_miR_2173 belong to the miR-19 family and target Kit and Gpnmb, respectively. The quantification of novel_miR_2622 and Kit revealed negative regulation, indicating that novel_miR_2622 may participate in embryonic pigmentation in P. sinensis by negatively regulating the expression of Kit. Conclusions miRNA act as master regulators of biological processes by controlling the expression of mRNAs. Considering their importance, the identified miRNAs and their target genes in Chinese soft-shelled turtle might be useful for investigating the molecular processes involved in pigmentation. All the results of this study may aid in the improvement of P. sinensis breeding traits for aquaculture.

A small skeletal fossil assemblage is described for the first time from the bioclastic limestone interbeds of the siltstone-dominated Guojiaba Formation, southern Shaanxi, China. The carbonate-hosted fossils include brachiopods (Eohadrotreta zhujiahensis, Eohadrotreta zhenbaensis, Spinobolus sp., Kuangshanotreta malungensis, Kyrshabaktella sp., Lingulellotreta yuanshanensis, Eoobolus incipiens, and Eoobolus sp.), sphenothallids (Sphenothallus sp.), archaeocyaths (Robustocyathus sp. and Yukonocyathus sp.), bradoriids (Kunmingella douvillei), chancelloriids sclerites (Onychia sp., Allonnia sp., Diminia sp., Archiasterella pentactina, and Chancelloria cf. eros), echinoderm plates, fragments of trilobites (Eoredlichia sp.), and hyolithelminths. The discovery of archaeocyaths in the Guojiaba Formation significantly extends their stratigraphic range in South China from the early Tsanglangpuian at least to the late Chiungchussuan. Thus, the Guojiaba Formation now represents the lowest known stratigraphic horizon where archaeocyath fossils have been found in the southern Shaanxi area. The overall assemblage is most comparable, in terms of composition, to Small skeletal fossil (SSF) assemblages from the early Cambrian Chengjiang fauna recovered from the Yu’anshan Formation in eastern Yunnan Province. The existing position that the Guojiaba Formation is correlated with Stage 3 in Cambrian Series 2 is strongly upheld based on the fossil assemblage recovered in this study.

Biological activity was the major triggering factor driving Earthâs organic and inorganic cycles across the biosphere, lithosphere, and atmosphere. A key question in the evolution of Earthâs ecosystem is when and how different animals emerged and flourished and how their appearance impacted the hydrosphere-atmosphere-lithosphere cycles. The Cambrian Explosion of metazoans in the EdiacaranâCambrian boundary interval resulted in sudden appearance of most of the readily fossilizable modern animal groups as macro-consumers in the Earthâs oceans. This explosive radiation event led for the first time to the emergence and diversification of animals on Earth, to the establishment of complex trophic webs with animals as consumers, and marks the onset of the Phanerozoic oceanic ecosystem. Our presentation aims to discuss the at least half-billion-year-old world of tubular and conical shelled organisms (sponges, conulariids, chancelloriids, hyoliths, mollusks, tommotiids, and other lophotrochozoans) that are unseen in the present-day oceans but were recovered by us from the siliciclastic and carbonate rocks in and outside of China. Additionally, to study the body fossils of exceptionally preserved biotas (Konversat-Lagerstätten) across China, efforts are underway to understand how the early animals, notably early bilaterians, created the over 500-million-year-old oceanic ecosystems without the influence of land plants, which appeared later.

Morphology usually serves as an effective proxy for functional ecology, and the evaluation of morphological, anatomical, and ecological changes allows for a deeper understanding of the nature of diversification and macroevolution. Lingulid (Order Lingulida) brachiopods were diverse and abundant during the early Palaeozoic, but decreased in diversity over time, with only a few genera of linguloids and discinoids present in modern marine ecosystems, frequently referred to as âliving fossilsâ. The dynamics that drove this decline remain unclear and it has not been determined if there is an associated decline in morphological and ecological diversity. We applied geometric morphometrics to reconstruct global morphospace occupied by lingulid brachiopods through the Phanerozoic, with results showing that maximum morphospace occupation was reached in the Early Ordovician. At this time of peak diversity, linguloids with sub-rectangular shells already possessed several evolutionary features common to all modern infaunal forms such as the rearrangement of mantle canals and reduction of the pseudointerarea. The end-Ordovician mass extinction had a differential effect on linguloids, disproportionally wiping out those with rounded shells whilst forms with sub-rectangular shells survived both the end-Ordovician and the PermianâTriassic mass extinctions, with post-extinction faunas predominantly composed of infaunal forms. For discinoids, both morphospace occupation and epi-benthic life strategies remain consistent through the Phanerozoic. Analysis of the morphospace occupation of lingulids over time, taking into account their body size, anatomical features and ecological changes, suggests that the reduced morphological and ecological diversity observed in modern lingulid brachiopods reflects evolutionary contingency rather than deterministic processes.

Hardgrounds are surfaces of synsedimentarily cemented carbonate beds that form at or near the seafloor. They are concentrated in particular periods of the geological record and their presence is closely linked to main climatic and biological events. For example, it has been proposed that early lithification of carbonate sediments facilitated the substantial increase of biodiversity during the Great Ordovician Biodiversification Event. Thus, identification of hardgrounds forms an integral component in documenting both geological and evolutionary events in the early Palaeozoic. Recognition of hardgrounds, including early Palaeozoic examples, is often not straightforward, usually because they lack encrustations and/or bioeroded grains and clasts. Due to the homogeneous texture of micrite, often bioeroded grains and clasts are hard to find and thus cannot be used for hardground identification. Hiatal surfaces, due to omission, are frequently associated with the development of hard substrate. Hiatal surfaces and hardgrounds are often characterised by occurrences of attached organisms, encrustations, truncation and signs of bioerosion. Borings are key evidence in investigations of hardground development. The unequivocal identification of borings is done through identification of the crosscutting relationship between the proposed boring and a hard substrate such as lithoclasts and/or shells. However, morphological criteria are difficult to use when trying to identify borings or burrows in a homogeneous substrate. Bioeroded hardgrounds and burrows with a micrite halo/lining are subjects to fracturing and reworking, resulting in accumulations of intraclasts in flat-pebble conglomerates (FPC). The recognition of borings and broken burrows with a halo can be challenging in FPC. Using trace fossils preserved in situ and in FPC in the late Cambrian carbonates of North China, we established a set of criteria for distinguishing borings from burrows with a halo in FPC. Features such as the relative volume of burrows and borings versus the host pebble and the number of traces per pebble, the cross-cutting relationship with laminae of different colour, and the presence of pyrite or glauconite encrustations can all be used for the recognition of borings. However, examination of the crosscutting relationship and encrustation are not sufficient on their own. Our results suggest caution by defining borings in FPC, particularly as synsedimentary deformation of burrows with a halo in the late Cambrian FPC can create structures similar to borings.

The Ordos Basin is located in the western part of the North China Platform and is the second largest sedimentary basin in China; the basin has a huge thickness of the Early Palaeozoic marine deposits, especially the Ordovician ones. The Zhaolaoyu Formation is distributed in the Fuping area of the southern Ordos Basin, where brachiopods, gastropods, graptolites, sponge spicules and ichnofossils are abundant. Ordovician gastropods are abundant, widespread and well known from different palaeocontinents across the world and are important for the study of biogeography and palaeoenvironments of the Ordovician. However, gastropods from the Ordovician in the Ordos Basin of North China have been rarely documented. The Early to Middle Ordovician of gastropod fauna from the Zhouzishan area, Inner Mongolia, western Ordos Basin, is dominated by the discoidal gastropods with a three to four whorls. Twelve genera of gastropods from the Ordovician of the western and southern Ordos Basin were documented, all with larger spire angle and up to four whorls. Since then, no other Ordovician gastropod fossils have been reported from the Ordos Basin. Herein, we reported and illustrated a gastropod fauna from the Late Ordovician in the Ordos Basin of North China. All gastropod specimens were preserved as internal moulds, which were manually picked from the residues after the samples were chemically dissolved in buffered acetic acid (5â10%). The fauna was recovered from the Zhaolaoyu Formation at the Zhaolaoyu section, Fuping County and consists of several species: Hormotoma sp., Lophonema sp., Lophospira sp. and Lophospira cf. sinensis. This fauna is dominated by high-spired gastropods with more than five whorls and provides an important supplement to the palaeontological information of the studied area.

The Chinese soft-shelled turtle (Pelodiscus sinensis) is one of the most important freshwater aquaculture reptiles in East and Southeast Asia. In contrast to the other strains of this species, the Qingxi black turtle has black skin. In this study, three Qingxi black turtles (WBF) and three Dongting Lake turtles (DTF) were investigated to compare and analyze their differences in skin color by mRNA sequencing and miRNA sequencing. Total of 1,772 differentially expressed mRNAs were identified including 1,079 upregulated and 693 downregulated in WBF. Through miRNA sequencing, 1,071 miRNAs were identified. Three- hundred nineteen miRNAs were differentially expressed, including 187 upregulated and 132 downregulated, which corresponded to 38,563 target mRNAs. Nine differentially expressed mRNAs and twelve differentially expressed miRNAs were validated by qRT-PCR. Integrated analysis of the profiles of differentially expressed miRNAs and mRNAs predicted 2,262 miRNA-mRNA interaction sites. Several mRNAs (such as tyr, mitf, gpnmb and kit) and miRNAs (such as miR-138, miR-383-3p, miR-1388b-5p and miR-18a-3p-3) involved in turtle skin pigmentation were identified. The results obtained in this study concerning mRNA-miRNA regulatory networks may help to establish a foundation for future research on the mechanisms underlying pigmentation in P. sinensis.

Although hemorrhagic sepsis caused by Aeromonas hydrophila infection is the dominant disease in the aquaculture of Chinese soft-shelled turtle, information on its molecular pathology is seriously limited. In this study, ninety turtles intraperitoneally injected with A. hydrophila exhibited two different phenotypes based on the pathological symptoms, referred to as active and inactive turtles. Comparative transcriptomes of liver and spleen from these two groups at 6, 24, and 72 h post-injection (hpi) were further analyzed. The results showed that cytokine–cytokine receptor interaction, PRRs mediated signaling pathway, apoptosis, and phagocytosis enriched in active and inactive turtles were significantly different. Pro-inflammatory cytokines, the TLR signaling pathway, NLR signaling pathway, and RLR signaling pathway mediating cytokine expression, and apoptosis-related genes, were significantly up-regulated in inactive turtles at the early stage (6 hpi). The significant up-regulation of phagocytosis-related genes occurred at 24 hpi in inactive turtles and relatively lagged behind those in active turtles. The anti-inflammatory cytokine, IL10, was significantly up-regulated during the tested periods (6, 24, and 72 hpi) in active turtles. These findings offer valuable information for the understanding of molecular immunopathogenesis after A. hydrophila infection, and facilitate further investigations on strategies against hemorrhagic sepsis in Chinese soft-shelled turtle T. sinensis.

Selective laser melting (SLM) is emerging as a promising 3D printing method for orthopedic and dental applications. However, SLM-based Ti6Al4V components frequently exhibit high roughness values and partial surface defects. Laser polishing (LP) is a newly developed technology to improve the surface quality of metals. In this research, LP is applied to improve the surface finish of components. The results show that the laser beam can neatly ablate the aggregates of metallic globules and repair cracks and pores on the surface, resulting in a smooth surface with nanocomposites. Overall, the results indicate that using LP optimizes surface morphology to favor fatigue behavior and osteoblastic differentiation. These findings provide foundational data to improve the surface roughness of a laser-polished implant and pave the way for optimized mechanical behavior and biocompatibility via the laser process.

Background: As intensive aquaculture practices have progressed, the prevalence of bacterial diseases in the Chinese soft-shell turtle (Pelodiscus sinensis) has escalated, particularly infections caused by Aeromonas hydrophila, such as ulcerative dermatitis and abscess disease. Despite this, little is known about their immune defenses against this pathogen. Methods: Our study pioneers an integrated analysis of transcriptomics and proteomics to investigate the immune responses of Chinese soft-shelled turtles to A. hydrophila infection. Results: The investigation revealed significant differences in immune-related pathways between groups susceptible and resistant to A. hydrophila infection after 4 days. A total of 4667 and 3417 differentially expressed genes (DEGs), 763 and 568 differentially expressed proteins (DEPs), and 13 and 5 correlated differentially expressed genes and proteins (cor-DEGs-DEPs) were identified in susceptible and resistant Chinese soft-shelled turtles, respectively. In the resistant group, upregulation of immune-related genes, such as CD3ε and CD45, enhanced T-cell activation and the immune response. The proteomic analysis indicated that immune proteins, such as NF-κB1, were significantly upregulated in the resistant group. The correlation analysis between transcriptomics and proteomics demonstrated that the CD40 gene and protein, differentially expressed in the resistant group compared to the control group, were commonly upregulated within the Toll-like receptor signaling pathway. Conclusions: The transcriptomic and proteomic data obtained from this study provide a scientific foundation for understanding the immune mechanisms that enable the Chinese soft-shelled turtle to resist A. hydrophila infection. [ABSTRACT FROM AUTHOR]

Hyolitha represent one of the major constituents of the Cambrian Evolutionary Fauna, first appearing in the Terreneuvian and rapidly diversifying soon after. Recent work has both enriched the hyolith fossil record and expanded our understanding of their biology, but studies documenting the evolutionary trajectory of Cambrian hyoliths remain scarce. Here we present the first study of changes in morphological disparity in Cambrian hyoliths over time with the aim of characterizing the evolutionary trajectory of hyoliths throughout their primary period of diversification. Our results show that hyoliths occupied distinct regions of morphospace at different times during the Cambrian, with an expansion in morphospace occupation associated with the increase in hyolith diversity in the early Cambrian. Both the Sinsk Event and multiple abiotic factors led to a decline in hyolith diversity in the Miaolingian, and morphological disparity also contracts in association with this reduction in diversity. [ABSTRACT FROM AUTHOR]

Abstract Background The incidence of spontaneous abortion (SA), which affects approximately 15–20% of pregnancies, is the most common complication of early pregnancy. Pathogenic copy number variations (CNVs) are recognized as potential genetic causes of SA. However, CNVs of variants of uncertain significance (VOUS) have been identified in products of conceptions (POCs), and their correlation with SA remains uncertain. Results Of 189 spontaneous abortion cases, trisomy 16 was the most common numerical chromosome abnormality, followed by monosomy X. CNVs most often occurred on chromosomes 4 and 8. Gene Ontology and signaling pathway analysis revealed significant enrichment of genes related to nervous system development, transmembrane transport, cell adhesion, and structural components of chromatin. Furthermore, genes within the VOUS CNVs were screened by integrating human placental expression profiles, PhyloP scores, and Residual Variance Intolerance Score (RVIS) percentiles to identify potential candidate genes associated with spontaneous abortion. Fourteen potential candidate genes (LZTR1, TSHZ1, AMIGO2, H1-4, H2BC4, H2AC7, H3C8, H4C3, H3C6, PHKG2, PRR14, RNF40, SRCAP, ZNF629) were identified. Variations in LZTR1, TSHZ1, and H4C3 may contribute to embryonic lethality. Conclusions CNV sequencing (CNV-seq) analysis is an effective technique for detecting chromosomal abnormalities in POCs and identifying potential candidate genes for SA.