Search Results (14)

Microplastic (MP) pollution is a major environmental problem, but a comparative study of the toxicological effects of different MPs remains lacking. To explore the toxicological effects of three different microplastics, namely, polypropylene (PP), polystyrene (PS) and polyethylene (PE), Zhenhai brown frog (Rana zhenhaiensis) tadpoles were used as the model animal. The results showed that exposure to PE and PS significantly reduced the metamorphosis rate of the tadpoles. Compared with the control group, the body weight of tadpoles in all MP treatments was significantly reduced compared with that of the control group. In addition, exposure to PE reduced the body length and hind limb length of tadpoles. The number of pigment cells increased and intercellular spaces expanded in the liver tissues of tadpoles receiving PS and PE treatments. The composition and function of the intestinal microbiota in the PP treatment and control groups were similar, whereas between the PS treatment and control, they differed. Liver transcriptome sequencing revealed significant alterations in key genes associated with oxidative stress, energy metabolism, immune response, and apoptosis signaling pathways with PS treatment and PP treatment. In summary, MPs may have harmed tadpoles to varying degrees by interfering with related signaling pathways. The negative effects of PE and PS were greater than those of PP. Full article

Background/Objective: Amphibian skin is a valuable source of host defense peptides (HDPs). This study aimed to identify HDPs with novel amino acid sequences from the skin of Rana tagoi yakushimensis and analyze their functions. Methods: cDNAs encoding HDP precursors were cloned and sequenced using RT-PCR and 3′-RACE. The novel HDPs were synthesized to evaluate their antimicrobial activity, antioxidant activity, and cytotoxicity. Antimicrobial activity was evaluated by way of broth microdilution and endotoxin- and β-glucan-binding capacity using an enzyme-linked endotoxin binding assay (ELEBA) and a modified ELEBA, respectively. Results: Nine cDNAs encoding precursors for various HDP families, including temporin, ranatuerin-2, brevinin-1, amurin-9, and a novel yakushimin peptide, were identified. Brevinin-1TYa exhibited antibacterial activity against Staphylococcus aureus, and brevinin-1TYa and amurin-9TYa induced morphological changes in Escherichia coli and S. aureus. Yakushimin-TYa, amurin-9TYa, and brevinin-1TYa showed concentration-dependent antibacterial effects against the plant pathogens Xanthomonas oryzae pv. oryzae and Clavibacter michiganensis subsp. michiganensis. Amurin-9TYa demonstrated strong binding affinity to lipopolysaccharide, lipoteichoic acid, and β-glucan, exhibited antioxidant activity, and lacked cytotoxicity, making it a promising therapeutic candidate. Moreover, brevinin-1TYa showed strong cytotoxicity, whereas yakushimin-TYa exhibited weak cytotoxicity. Conclusions: These findings highlight the potential of these peptides, particularly amurin-9TYa, for future applications as antimicrobial and therapeutic agents. Full article

To mitigate problems concerning small-sized spots on apple leaves and the difficulties associated with the accurate detection of spot targets exacerbated by the complex backgrounds of orchards, this research used alternaria leaf spots, rust, brown spots, gray spots, and frog eye leaf spots on apple leaves as the research object and proposed the use of a high-accuracy detection model YOLOv5-Res (YOLOv5-Resblock) and lightweight detection model YOLOv5-Res4 (YOLOv5-Resblock-C4). Firstly, a multiscale feature extraction module, ResBlock (residual block), was designed by combining the Inception multi-branch structure and ResNet residual idea. Secondly, a lightweight feature fusion module C4 (CSP Bottleneck with four convolutions) was designed to reduce the number of model parameters while improving the detection ability of small targets. Finally, a parameter-streamlining strategy based on an optimized model architecture was proposed. The experimental results show that the performance of the YOLOv5-Res model and YOLOv5-Res4 model is significantly improved, with the mAP0.5 values increasing by 2.8% and 2.2% compared to the YOLOv5s model and YOLOv5n model, respectively. The sizes of the YOLOv5-Res model and YOLOv5-Res4 model are only 10.8 MB and 2.4 MB, and the model parameter counts are reduced by 22% and 38.3% compared to the YOLOv5s model and YOLOv5n model. Full article

Rana temporaria is one of the most widespread Palearctic brown frogs. We aimed to clarify distribution pattern of two main genetic clades in the understudied Balkan peninsula by using 16SrRNA and MT-CYTB sequences, already widely applied in analyses of populations from other parts of Europe, while focusing on the broad area along the Morava river (central Balkans) as a known gap in the species distribution. Additionally, we were interested in revealing the extent of haplotype diversity within the main genetic clades in the Balkans, particularly around the supposed suture zone. The results revealed a suture zone between the Western and Eastern Clades in the central part of the Balkan Peninsula. This indicated the existence of a historical barrier between the Balkan Mountain Belt and geographically close mountains surrounding the Vlasina Plateau (Rhodope/Serbian–Macedonian Massif). The overall observed haplotype diversity in populations of R. temporaria from the Balkan Peninsula seems high. Harboring both main genetic clades of R. temporaria qualifies the Balkan Peninsula as another important center of species’ genetic diversity, as well as rich in unique haplotypes. This points out the necessity of applying conservation measures focused on the common European frog populations and habitats in this part of the species’ distribution area. Full article

Sex chromosome turnover is the transition between sex chromosomes and autosomes. Although many cases have been reported in poikilothermic vertebrates, their evolutionary causes and genetic mechanisms remain unclear. In this study, we report multiple transitions between the Y chromosome and autosome in the Japanese Tago’s brown frog complex. Using chromosome banding and molecular analyses (sex-linked and autosomal single nucleotide polymorphisms, SNPs, from the nuclear genome), we investigated the frogs of geographic populations ranging from northern to southern Japan of two species, Rana tagoi and Rana sakuraii (2n = 26). Particularly, the Chiba populations of East Japan and Akita populations of North Japan in R. tagoi have been, for the first time, investigated here. As a result, we identified three different sex chromosomes, namely chromosomes 3, 7, and 13, in the populations of the two species. Furthermore, we found that the transition between the Y chromosome (chromosome 7) and autosome was repeated through hybridization between two or three different populations belonging to the two species, followed by restricted chromosome introgression. These dynamic sex chromosome turnovers represent the first such findings in vertebrates and imply that speciation associated with inter- or intraspecific hybridization plays an important role in sex chromosome turnover in frogs. Full article

Jiuzhaigou National Nature Reserve (JNNR) is a renowned World Biosphere Reserve and UNESCO-designated World Nature Heritage Site. The age structure and body size of a population are crucial for assessing the quality of habitats in which a population lives and are essential for the vertebrate conservation and management, especially for amphibians. Unfortunately, information about the life history traits of amphibians is currently unavailable in JNNR. Herein, we first estimated the age structure and body size of Rana kukunoris, which is endemic to the Eastern Qinghai-Xizang Plateau. Then, we compared our data with 28 reported populations along an elevation gradient (1797–3450 m) and investigated how life history traits respond to climatic variations. Our results indicated the following: (1) For individuals from JNNR, the maximum longevity is 8 years, age at sexual maturity (ASM) is 2 years, suggesting a favorable ecological environment in JNNR. Notably, females are significantly larger than males due to the age factor. (2) The average age and ASM show a positive correlation with elevation. However, when the elevation exceeds 3000 m, the average SVL initially increases and then decreases due to the harsh environmental conditions at higher elevation. (3) Temperature and/or UV-B have a significant impact on the average age, ASM, and average SVL variations of R. kukunoris, suggesting adaptive potential of this species via life history variations in light of environmental changes. These accounts provide antecedent information about the life history traits of amphibians in JNNR, and provide insights into the driving factors of the life history variations of the plateau brown frog. Full article

The brown frog (Rana dybowskii) exhibits a wide distribution and is extensively cultured in northeast China. This species undergoes a prolonged period of hibernation lasting from several months to half a year. The frog’s fallopian tubes are considered a valuable tonic medicine known as “Oviducts Ranae” in traditional Chinese medicine. To enhance comprehension of the molecular mechanism underlying the process of emergence from hibernation, a transcriptome-based comparative analysis was performed on differentially expressed genes (DEGs) across various organs of female frogs during hibernation and upon emergence. The organs examined encompassed the brain, liver, spleen, fallopian tube, and ovary. Subsequently, GO and KEGG enrichment analyses were performed to gain further insights into these DEGs. A total of 51,634 transcripts were identified in all five tissues. The spleen exhibited the highest number of DEGs, with 3651 members, while the liver, brain, and fallopian tube had 3182, 3115, and 3186 DEGs, respectively. The ovary had the lowest number of DEGs, with only 1661. Interestingly, only 45 genes were found to be differentially expressed in all five tissues, and GO enrichment analysis revealed distinct functional differences among the DEGs in the various tissues. Only two meaningful DEG-enriched KEGG pathways, “00310 Lysine degradation” and “05202 Transcriptional misregulation in cancer”, were present in all five tissues, and the pathway “B 09182 Protein families: genetic information processing” was significantly enriched in four tissues except the ovary, and it had the most enriched DEGs. Our findings offer insights to grasp the factors that need to be controlled in the design of overwintering sites and offer a novel perspective for the conservation and management of the overwintering population of female R. dybowskii. Full article

Peptides released on frogs’ skin in a stress situation represent their only weapon against micro-organisms and predators. Every species and even population of frog possesses its own peptidome being appropriate for their habitat. Skin peptides are considered potential pharmaceuticals, while the whole peptidome may be treated as a taxonomic characteristic of each particular population. Continuing the studies on frog peptides, here we report the peptidome composition of the Central Slovenian agile frog Rana dalmatina population. The detection and top-down de novo sequencing of the corresponding peptides was conducted exclusively by tandem mass spectrometry without using any chemical derivatization procedures. Collision-induced dissociation (CID), higher energy collision-induced dissociation (HCD), electron transfer dissociation (ETD) and combined MS³ method EThcD with stepwise increase of HCD energy were used for that purpose. MS/MS revealed the whole sequence of the detected peptides including differentiation between isomeric Leu/Ile, and the sequence portion hidden in the disulfide cycle. The array of the discovered peptide families (brevinins 1 and 2, melittin-related peptides (MRPs), temporins and bradykinin-related peptides (BRPs)) is quite similar to that of R. temporaria. Since the genome of this frog remains unknown, the obtained results were compared with the recently published transcriptome of R. dalmatina. Full article

The core objective of forensic DNA typing is developing DNA profiles from biological evidence for personal identification. The present study was designed to check the validation of the IrisPlex system and the Prevalence of eye colour in the Pakhtoon population residing within the Malakand Division. Methods: Eye colour digital photographs and buccal swab samples of 893 individuals of different age groups were collected. Multiplexed SNaPshot single base extension chemistry was used, and the genotypic results were analysed. Snapshot data were used for eye colour prediction through the IrisPlex and FROG-kb tool. Results: The results of the present study found brown eye colour to be the most prevalent eye colour in comparison to intermediate and blue coloured. Overall, individuals with brown-coloured eyes possess CT (46.84%) and TT (53.16%) genotypes. Blue eye-coloured individuals are solely of the CC genotype, while individuals of intermediate eye colour carry CT (45.15%) and CC (53.85%) genotypes in rs12913832 SNP in the HERC2 gene. It was also revealed that brown-coloured eyes individuals were dominant among all age groups followed by intermediate and blue. Statistical analysis between particular variables and eye colour showed a significant p-value (<0.05) for rs16891982 SNP in SLC45A2 gene, rs12913832 SNP in HERC2 gene, rs1393350 SNP in SLC45A2, districts and gender. The rest of the SNPs were non-significant with eye colour, respectively. The rs12896399 SNP and SNP rs1800407 were found significant with rs16891982 SNP. The result also demonstrated that the study group differs from the world population based on eye colour. The two eye colour prediction results were compared, and it was discovered that IrisPlex and FROG-Kb had similar higher prediction ratios for Brown and Blue eye colour. Conclusions: The results of the current study revealed brown eye colour to be the most prevalent amongst members of the local population of Pakhtoon ethnicity in the Malakand Division of northern Pakistan. A set of contemporary human DNA samples with known phenotypes are used in this research to evaluate the custom panel’s prediction accuracy. With the aid of this forensic test, DNA typing can be supplemented with details about the appearance of the person from whom the sample was taken in cases involving missing persons, ancient human remains, and trace samples. This study may be helpful for future population genetics and forensics studies. Full article

Most animal species are detected imperfectly and overlooking individuals can result in a biased inference of the abundance patterns and underlying processes. Several techniques can incorporate the imperfect detection process for a more accurate estimation of abundance, but most of them require repeated surveys, i.e., more sampling effort compared to single counts. In this study, we used the dependent double-observer approach to estimate the detection probability of the egg clutches of two brown frog species, Rana dalmatina and R. latastei. We then simulated the data of a declining population at different levels of detection probability in order to assess under which conditions the double counts provided better estimates of population trends compared to naïve egg counts, given the detectability of frog clutches. Both species showed a very high detection probability, with average values of 93% for Rana dalmatina and 97% for R. latastei. Simulations showed that not considering imperfect detection reduces the power of detecting population trends if detection probability is low. However, at high detection probability (>80%), ignoring the imperfect detection does not bias the estimates of population trends. This suggests that, for species laying large and easily identifiable egg clutches, a single count can provide useful estimates if surveys are correctly timed. Full article

We describe two new species of terrestrial-breeding frogs in the genus Pristimantis from the Andes of northeastern Peru, Amazonas Department. Both species share several characters with other congeners from northern Peru, such as the presence of prominent conical tubercles on their eyelids and heel, prominent conical tubercles along the outer edge of the tarsus, and discs on fingers and toes widely expanded. However, both species can be diagnosed from morphologically similar Pristimantis in the region. Pristimantis kiruhampatu has axillae, groins, and hidden surfaces of hindlimbs that are cherry with white minute flecks, tympanic membrane and tympanic annulus evident, conical tubercles along the edge of snout and outer edge of tibia, and \/ shaped folds in the scapular region. Pristimantis paulpittmani has yellow or dirty cream groins and hidden surfaces of hindlimbs, whitish cream irises with scattered dark brown reticulations, and a thin vertical dark brown streak at the middle of the eye, snout subacuminate with a conical tubercle at the tip, and lacks a tympanic annulus and membrane. Additionally, we provide a short description of the advertisement call of P. kiruhampatu. Full article

Several anurans have broad elevational and latitudinal distribution ranges; distinct species and populations may face various environmental and selection stresses. Due to their environmental sensitivity, adaptation is critical for the long-term persistence of anurans. Previous studies have tried to identify the ecogeographical pattern and its mechanism in anurans, suggesting different patterns, but the related explanatory mechanisms are yet to be generally supported and are suggested to be complicated. To explore the elusive mechanisms, we studied the morphological variation of the plateau brown frog (Rana kukunoris) along an elevational gradient on the eastern margin of the Qinghai–Tibetan Plateau. Using body size, extremity length, and the ratio between them (extremities/body size) as testing indicators, we examined potential ecogeographical adaptations and investigated how environmental and biological factors could shape the morphological development in R. kukunoris. We found that males and females showed different variations in body size and extremities along the elevational gradient, whereas both of them showed a decreasing extremities/body size ratio along elevation. Together with the strong correlations between environmental and biological factors and the morphometrics, we identified ecogeographical adaptation and a sexual difference in the selective pressures on the extremities and body size of the plateau brown frog. Our results imply that geographic variations in anuran morphological traits should be understood as an outcome of environmental and biological factors. Furthermore, ecogeographical adaptation in anurans can manifest as an interactive change between body size and extremities. Full article

Translocation between sex-chromosomes and autosomes generates multiple sex-chromosome systems. It happens unexpectedly, and therefore, the evolutionary meaning is not clear. The current study shows a multiple sex chromosome system comprising three different chromosome pairs in a Taiwanese brown frog (Odorrana swinhoana). The male-specific three translocations created a system of six sex-chromosomes, ♂X₁Y₁X₂Y₂X₃Y₃-♀X₁X₁X₂X₂X₃X₃. It is unique in that the translocations occurred among three out of the six members of potential sex-determining chromosomes, which are known to be involved in sex-chromosome turnover in frogs, and the two out of three include orthologs of the sex-determining genes in mammals, birds and fishes. This rare case suggests sex-specific, nonrandom translocations and thus provides a new viewpoint for the evolutionary meaning of the multiple sex chromosome system. Full article

As one of most important traditional Chinese medicine resources, the oviduct of female Rana chensinensis (Chinese brown frog) was widely used in the treatment of asthenia after sickness or delivery, deficiency in vigor, palpitation, and insomnia. Unlike other vertebrates, the oviduct of Rana chensinensis oviduct significantly expands during prehibernation, in contrast to the breeding period. To explain this phenomenon at the molecular level, the protein expression profiles of Rana chensinensis oviduct during the breeding period and prehibernation were observed using isobaric tags for relative and absolute quantitation (iTRAQ) technique. Then, all identified proteins were used to obtain gene ontology (GO) annotation. Ultimately, KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analysis was performed to predict the pathway on differentially expressed proteins (DEPs). A total of 4479 proteins were identified, and 312 of them presented different expression profiling between prehibernation and breeding period. Compared with prehibernation group, 86 proteins were upregulated, and 226 proteins were downregulated in breeding period. After KEGG enrichment analysis, 163 DEPs were involved in 6 pathways, which were lysosome, RNA transport, glycosaminoglycan degradation, extracellular matrix (ECM)–receptor interaction, metabolic pathways and focal adhesion. This is the first report on the protein profiling of Rana chensinensis oviduct during the breeding period and prehibernation. Results show that this distinctive physiological phenomenon of Rana chensinensis oviduct was mainly involved in ECM–receptor interaction, metabolic pathways, and focal adhesion. Full article