BACKGROUND: Babesia spp. are protozoan parasites that infect the red blood cells of domesticated animals, wildlife and humans. A few cases of giant pandas (a flagship species in terms of wildlife conservation) infected with a putative novel Babesia sp. have been reported. However, comprehensive research on the morphological and molecular taxonomic classification of this novel Babesia sp. is still lacking. This study was designed to close this gap and formally describe this new Babesia sp. infecting giant pandas.
METHODS: Detailed morphological, molecular and phylogenetic analyses were conducted to characterise this Babesia sp. and to assess its systematic relationships with other Babesia spp. Blood samples from giant pandas infected with Babesia were subjected to microscopic examination. The 18S ribosomal RNA (18S rRNA), cytochrome b (cytb) and mitochondrial genome (mitogenome) of the new Babesia sp. were amplified, sequenced and assembled using DNA purified from blood samples taken from infected giant pandas. Based on the newly generated 18S rRNA, cytb and mitogenome sequences, phylogenetic trees were constructed.
RESULTS: Morphologically, the Babesia sp. from giant pandas exhibited various forms, including round to oval ring-shaped morphologies, resembling those found in other small canine Babesia spp. and displaying typical tetrads. Phylogenetic analyses with the 18S rRNA, cytb and mitogenome sequences revealed that the new Babesia sp. forms a monophyletic group, with a close phylogenetic relationship with the Babesia spp. that infect bears (Ursidae), raccoons (Procyonidae) and canids (Canidae). Notably, the mitogenome structure consisted of six ribosomal large subunit-coding genes (LSU1-6) and three protein-coding genes (cytb, cox3 and cox1) arranged linearly.
CONCLUSIONS: Based on coupled morphological and genetic analyses, we describe a novel species of the genus Babesia, namely, Babesia ailuropodae n. sp., which infects giant pandas.

UNASSIGNED: Wild rodents can serve as reservoirs or carriers of E. bieneusi, thereby enabling parasite transmission to domestic animals and humans. This study aimed to investigate the prevalence of E. bieneusi in wild rodents from the Inner Mongolian Autonomous Region and Liaoning Province of China. Moreover, to evaluate the potential for zoonotic transmission at the genotype level, a genetic analysis of the isolates was performed.
UNASSIGNED: A total of 486 wild rodents were captured from two provinces in China. Polymerase chain reaction (PCR) was performed to amplify the vertebrate cytochrome b (cytb) gene in the fecal DNA of the rodents to detect their species. The genotype of E. bieneusi was determined via PCR amplification of the internal transcribed spacer (ITS) region of rDNA. The examination of genetic characteristics and zoonotic potential requires the application of similarity and phylogenetic analysis.
UNASSIGNED: The infection rates of E. bieneusi in the four identified rodent species were 5.2% for Apodemus agrarius (n = 89), 4.5% for Cricetulus barabensis (n = 96), 11.3% for Mus musculus (n = 106), and 38.5% for Rattus norvegicus (n = 195). Infection was detected at an average rate of 17.4% among 486 rodents. Of the 11 identified genotypes, nine were known: SHR1 (detected in 32 samples), D (30 samples), EbpA (9 samples), PigEbITS7 (8 samples), HNR-IV (6 samples), Type IV (5 samples), HNR-VII (2 samples), HNH7 (1 sample), and HNPL-V (1 sample). Two novel genotypes were also discovered, NMR-I and NMR-II, each comprising one sample. The genotypes were classified into group 1 and group 13 via phylogenetic analysis.
UNASSIGNED: Based on the initial report, E. bieneusi is highly prevalent and genetically diverse in wild rodents residing in the respective province and region. This indicates that these animals are crucial for the dissemination of E. bieneusi. Zoonotic E. bieneusi-carrying animals present a significant hazard to local inhabitants. Therefore, it is necessary to increase awareness regarding the dangers presented by these rodents and reduce their population to prevent environmental contamination.

Wild rodents are key carriers of various human pathogens, including Blastocystis spp. Our study aimed to assess the prevalence and genetic characteristics of Blastocystis among wild rodents in the Inner Mongolian Autonomous Region and Liaoning Province of China. From November 2023 to February 2024, 486 rodents were captured in these regions. Fresh feces were collected from the intestines of each rodent for the isolation of DNA and PCR amplification of the vertebrate cytochrome b (cytb) gene to identify rodent species. Subsequently, PCR analysis and sequencing of the partial small subunit of the ribosomal RNA (rRNA) gene were utilized to detect Blastocystis in all fecal samples. Of the total samples, 27.4% (133/486) were found to be Blastocystis positive. The results revealed the presence of four species of rodents infected with Blastocystis, 32.3% (63/195) in Rattus norvegicus, 15.1% (16/106) in Mus musculus, 20.2% (18/89) in Apodemus agrarius, and 37.5% (36/96) in Cricetulus barabensis. Sequence analysis confirmed the existence of five Blastocystis subtypes: ST1 (n = 4), ST2 (n = 2), the ST4 (n = 125, the dominant subtype), ST10 (n = 1), and a novel ST (n = 1). The identified zoonotic subtypes (ST1, ST2, ST4, and ST10) highlight the possible role played by wild rodents in the transmission of Blastocystis to humans, thereby elevating the chances of human infection. Meanwhile, the discovery of novel sequences also provides new insights into the genetic diversity of this parasite.
UNASSIGNED: Enquête moléculaire sur les infections à Blastocystis chez des rongeurs sauvages de la région autonome de Mongolie intérieure et de la province du Liaoning, Chine : forte prévalence et dominance du sous-type ST4.
UNASSIGNED: Les rongeurs sauvages sont des vecteurs clés de divers agents pathogènes humains, dont Blastocystis spp. Notre étude visait à évaluer la prévalence et les caractéristiques génétiques de Blastocystis chez les rongeurs sauvages de la région autonome de Mongolie intérieure et de la province chinoise du Liaoning. De novembre 2023 à février 2024, 486 rongeurs ont été capturés dans ces régions. Des matières fécales fraîches ont été collectées dans les intestins de chaque rongeur pour l’isolement de l’ADN et l’amplification par PCR du gène du cytochrome b des vertébrés (cytb) afin d’identifier les espèces de rongeurs. Par la suite, l’analyse PCR et le séquençage de la petite sous-unité partielle du gène de l’ARN ribosomal (ARNr) ont été utilisés pour détecter les Blastocystis dans tous les échantillons fécaux. Sur le total des échantillons, 27.4% (133/486) présentaient un résultat positif à Blastocystis. Les résultats ont révélé la présence de quatre espèces de rongeurs infectées par Blastocystis, 32.3% (63/195) chez Rattus norvegicus, 15.1% (16/106) chez Mus musculus, 20.2% (18/89) chez Apodemus agrarius et 37.5% (36/96) chez Cricetulus barabensis. L’analyse de séquence a confirmé l’existence de cinq sous-types de Blastocystis : ST1 (n = 4), ST2 (n = 2), ST4 (n = 125, le sous-type dominant), ST10 (n = 1) et un nouveau ST (n = 1). Les sous-types zoonotiques identifiés (ST1, ST2, ST4 et ST10) mettent en évidence le rôle possible joué par les rongeurs sauvages dans la transmission de Blastocystis à l’Homme, augmentant ainsi les risques d’infection humaine. Parallèlement, la découverte de nouvelles séquences fournit également de nouvelles informations sur la diversité génétique de ce parasite.

Three nominal species of the killifish genus Aplocheilus are reported from the lowlands of Sri Lanka. Two of these, Aplocheilus dayi and Aplocheilus werneri, are considered endemic to the island, whereas Aplocheilus parvus is reported from both Sri Lanka and Peninsular India. Here, based on a collection from 28 locations in Sri Lanka, also including a dataset of Asian Aplocheilus downloaded from GenBank, we present a phylogeny constructed from the mitochondrial cytochrome b (cytb), mitochondrial cytochrome c oxidase subunit 1 (cox1), and nuclear recombination activating protein 1 (rag1), and investigate the interrelationships of the species of Aplocheilus in Sri Lanka. The endemic Sri Lankan aplocheilid clade comprising A. dayi and A. werneri is recovered as the sister group to the clade comprising A. parvus from Sri Lanka and Aplocheilus blockii from Peninsular India. The reciprocal monophyly of A. dayi and A. werneri is not supported in our molecular phylogeny. A. dayi and A. werneri display strong sexual dimorphism, but species-level differences are subtle, explained mostly by pigmentation patterns. Their phenotypes exhibit a parapatric distribution and may represent locally adapted forms of a single species. Alternatively, the present study does not rule out the possibility that A. dayi and A. werneri may represent an incipient species pair or that they have undergone introgression or hybridization in their contact zones. We provide evidence that the Nilwala-Gin region of southwestern Sri Lanka may have acted as a drought refugium for these fishes.

N-(1,3-dimethylbutyl)-N\'-phenyl-p-phenylenediamine quinone (6-PPDQ) is an emerging pollutant transformed from 6-PPD. However, the effect of 6-PPDQ exposure on mitochondrion and underlying mechanism remains largely unclear. Using Caenorhabditis elegans as animal model, exposed to 6-PPDQ at 0.1-10 μg/L was performed form L1 larvae to adult day-1. Exposure to 6-PPDQ (1 and 10 μg/L) could increase oxygen consumption rate and decease adenosine 5\'-triphosphate (ATP) content, suggesting induction of mitochondrial dysfunction. Activities of NADH dehydrogenase (complex I) and succinate dehydrogenase (complex II) were inhibited, accompanied by a decrease in expressions of gas-1, nuo-1, and mev-1. RNAi of gas-1 and mev-1 enhanced mitochondrial dysfunction and reduced lifespan of 6-PPDQ exposed nematodes. GAS-1 and MEV-1 functioned in parallel to regulate 6-PPDQ toxicity to reduce the lifespan. Insulin peptides and the insulin signaling pathway acted downstream of GAS-1 and MEV-1 to control the 6-PPDQ toxicity on longevity. Moreover, RNAi of sod-2 and sod-3, targeted genes of daf-16, caused susceptibility to 6-PPDQ toxicity in reducing lifespan and in causing reactive oxygen species (ROS) production. Therefore, 6-PPDQ at environmentally relevant concentrations (ERCs) potentially caused mitochondrial dysfunction by affecting mitochondrial complexes I and II, which was associated with lifespan reduction by affecting insulin signaling in organisms.

The mitochondrial genome transcribes 13 mRNAs coding for well-known proteins essential for oxidative phosphorylation. We demonstrate here that cytochrome b (CYTB), the only mitochondrial-DNA-encoded transcript among complex III, also encodes an unrecognized 187-amino-acid-long protein, CYTB-187AA, using the standard genetic code of cytosolic ribosomes rather than the mitochondrial genetic code. After validating the existence of this mtDNA-encoded protein arising from cytosolic translation (mPACT) using mass spectrometry and antibodies, we show that CYTB-187AA is mainly localized in the mitochondrial matrix and promotes the pluripotent state in primed-to-naive transition by interacting with solute carrier family 25 member 3 (SLC25A3) to modulate ATP production. We further generated a transgenic knockin mouse model of CYTB-187AA silencing and found that reduction of CYTB-187AA impairs females\' fertility by decreasing the number of ovarian follicles. For the first time, we uncovered the novel mPACT pattern of a mitochondrial mRNA and demonstrated the physiological function of this 14th protein encoded by mtDNA.

Alveolar echinococcosis (AE), caused by Echinococcus multilocularis, is an important zoonotic disease. Yili Prefecture in Xinjiang is endemic for AE, however the molecular variability of E. multilocularis in this region is poorly understood. In this study, 127 samples were used for haplotypes analysis, including 79 tissues from humans, 43 liver tissues from small rodents, and 5 fecal samples from dogs. Genetic variability in E. multilocularis was studied using complete sequences of the mitochondrial (mt) genes of cytochrome b (cob), NADH dehydrogenase subunit 2 (nad2), and cytochrome c oxidase subunit 1 (cox1), using a total of 3558 bp per sample. The Asia haplotype 2 (A2) was the dominant haplotype, with 72.15% (57/79) prevalence in humans, 2.33% (1/43) in small rodents, and 80.00% (4/5) in dogs, followed by A5, the second most common haplotype, which infected 27.91% (12/43) small rodents. Haplotype network analysis showed that all haplotypes clustered together with the Asian group. Pairwise fixation index (FST) values showed lower level of genetic differentiation between different regions within the country. Compared with the sequences of E. multilocularis from North America and Europe, all concatenated sequences isolated from Yili Prefecture were highly differentiated and formed a single population. The A2 haplotype, analyzed using the cob, nad2, and cox1 genes of E. multilocularis, is the predominant variant in humans and dogs in Yili Prefecture.

Ginkgo biloba leaf extract (GBE) can effectively treat bloom-forming freshwater algae. However, there is limited information about the underlying suppression mechanism of the marine bloom-forming Prorocentrum donghaiense-the most dominant algal bloom species in the East China Sea. We investigated the effect of GBE on P. donghaiense in terms of its response to photosynthesis at the molecular/omic level. In total, 93,743 unigenes were annotated using six functional databases. Furthermore, 67,203 differentially expressed genes (DEGs) were identified in algae treated with 1.8 g∙L-1 GBE. Among these DEGs, we identified the genes involved in photosynthesis. PsbA, PsbB and PsbD in photosystem II, PsaA in photosystem I, and PetB and PetD in the cytochrome b6/f complex were downregulated. Other related genes, such as PsaC, PsaE, and PsaF in photosystem I; PetA in the cytochrome b6/f complex; and atpA, atpD, atpH, atpG, and atpE in the F-type H+-ATPase were upregulated. These results suggest that the structure and activity of the complexes were destroyed by GBE, thereby inhibiting the electron flow between the primary and secondary quinone electron acceptors, primary quinone electron acceptor, and oxygen-evolving complex in the PSII complex, and interrupting the electron flow between PSII and PSI, ultimately leading to a decline in algal cell photosynthesis. These findings provide a basis for understanding the molecular mechanisms underlying P. donghaiense exposure to GBE and a theoretical basis for the prevention and control of harmful algal blooms.

A total of 10 specimens of Alcyonacea corals were collected at depths ranging from 905 m to 1 633 m by the manned submersible Shenhai Yongshi during two cruises in the South China Sea (SCS). Based on mitochondrial genomic characteristics, morphological examination, and sclerite scanning electron microscopy, the samples were categorized into four suborders (Calcaxonia, Holaxonia, Scleraxonia, and Stolonifera), and identified as 9 possible new cold-water coral species. Assessments of GC-skew dissimilarity, phylogenetic distance, and average nucleotide identity (ANI) revealed a slow evolutionary rate for the octocoral mitochondrial sequences. The nonsynonymous ( Ka) to synonymous ( Ks) substitution ratio ( Ka/ Ks) suggested that the 14 protein-coding genes (PCGs) were under purifying selection, likely due to specific deep-sea environmental pressures. Correlation analysis of the median Ka/ Ks values of five gene families and environmental factors indicated that the genes encoding cytochrome b (cyt b) and DNA mismatch repair protein ( mutS) may be influenced by environmental factors in the context of deep-sea species formation. This study highlights the slow evolutionary pace and adaptive mechanisms of deep-sea corals.
在“深海勇士”号载人潜水器在南海进行了两次科考过程中，在905米至1 633米的深度范围内共采集了10株软珊瑚目珊瑚。利用线粒体基因组特征结合形态学特征分析表明，所收集的冷水珊瑚新种隶属于Calcaxonia、Holaxonia、Scleraxonia和Stolonifera 4个亚目，代表了9个新种。线粒体基因组GC-skew、系统发育距离和平均核苷酸相似度的差异分析显示，八放珊瑚线粒体序列的进化较为缓慢。非同义( Ka)和同义( Ks)替换( Ka/ Ks)比值表明，14个蛋白质编码基因(PCGs)受净化选择，选择压力可能来自特定的深海环境。5个基因家族的 Ka/ Ks中值与环境因子的相关性分析发现，编码细胞色素 b (cyt b)和DNA错配修复蛋白( mutS)的基因可能受到环境因子的驱动在而形成深海物种过程中发挥重要作用。该研究强调了深海珊瑚的缓慢进化和深海适应机制。.

In situ analysis of membrane protein-ligand interactions under physiological conditions is of significance for both fundamental and applied science, but it is still a big challenge due to the limits in sensitivity and selectivity. Here, we demonstrate the potential of surface-enhanced resonance Raman spectroscopy (SERRS) for the investigation of membrane protein-protein interactions. Lipid biolayers are successfully coated on silver nanoparticles through electrostatic interactions, and a highly sensitive and biomimetic membrane platform is obtained in vitro. Self-assembly and immobilization of the reduced cytochrome b5 on the coated membrane are achieved and protein native biological functions are preserved. Owing to resonance effect, the Raman fingerprint of the immobilized cytochrome b5 redox center is selectively enhanced, allowing for in situ and real-time monitoring of the electron transfer process between cytochrome b5 and their partners, cytochrome c and myoglobin. This study provides a sensitive analytical approach for membrane proteins and paves the way for in situ exploration of their structural basis and functions.