摘要: This year marks a significant milestone as we celebrate the75th anniversary of our nation, alongside the 65th anniversary of the Kunming Institute of Zoology（KIZ） and the 75^th anniversary of the Chinese Academy of Sciences（CAS）. This juncture provides an opportunity to reflect on our progress over the past five years and strategically enhance our culture of innovation, while pursuing new aspirations（Yao & Shen,2019）. It is a critical moment to advance innovation and take decisive steps toward leadership in this new era.

摘要: The CRISPR-Cas13 system, an RNA-guided editing tool,has emerged as a highly efficient and stable RNA editing technique. Although the CRISPR-Cas13 system has been developed in several insect species, its application in lepidopterans has not yet been reported. In the present study, we evaluated the RNA cleavage activity of the CRISPR-Cas13 system in the silkworm(Bombyx mori), a model lepidopteran insect, both ex vivo and in vivo. We established two stable silkworm BmE cell lines expressing PspCas13b and CasRx, respectively. Further analysis demonstrated that both PspCas13b and CasRx effectively down-regulated the transcription of exogenouslyintroduced target and endogenous genes in these cell lines. In addition, we generated two transgenic silkworm strains, one expressing CasRx and the other expressing RNA-guided CRISPR RNA targeting Sex combs reduced(Scr). Further crossing experiments showed that CasRx induced a down-regulation of Scr transcription in silkworms, which impaired systemic growth of larvae.Overall, this study demonstrated that the CRISPR-Cas13RNA editing system works efficiently in the silkworm,providing a potential alternative approach for RNA manipulation in lepidopteran insects.

摘要: Hematopoiesis originates in the yolk sac, which forms prior to the establishment of blood circulation and exhibits distinct developmental processes between primates and mice. Despite increasing appreciation of yolk sac hematopoiesis for its lifelong contribution to the adult hematopoietic system and its regulatory roles in organogenesis, cross-species differences, particularly before the onset of blood circulation, remain incompletely understood. In this study, we constructed an integrative cross-species transcriptome atlas of pre-circulation hematopoiesis in humans, monkeys(Macaca fascicularis),and mice. This analysis identified conserved populations between primates and mice, while also revealing more differentiated myeloid, erythroid, and megakaryocytic lineages in pre-circulation primates compared to mice.Specifically,SPP1-expressingmacrophageswere detected in primates before the onset of blood circulation but were absent in mice. Cell-cell communication analysis identified CSF1+ extraembryonic mesoderm cells as a potential supportive niche for macrophage generation, with ligand-receptor interactions between macrophages and other cell populations in the human yolk sac. Interestingly,pre-circulation SPP1+ macrophages exhibited hallmark signatures reminiscent of a macrophage subset that positively regulates hematopoietic stem cell generation.Our findings provide a valuable cross-species resource,advancing our understanding of human pre-circulation yolk sac hematopoiesis and offering a theoretical basis for the regeneration of functional blood cells.

摘要: In group-living animals, chronic juvenile social isolation stress(SIS) can profoundly affect behavior and neuroendocrine regulation. However, its impact on social behavior in avian species, particularly regarding sexspecific neural circuit differences, remains underexplored.This study focused on zebra finches, a species known for its social clustering and cognitive abilities, to elucidate these influences. Results indicated that SIS significantly increased plasma corticosterone levels in females but not in males, suggesting a heightened stress response and susceptibility in females. Additionally, SIS disrupted sociality and flocking behavior in both sexes, with more severe impairments in social recognition observed in females. Mesotocin(MT) levels in the lateral septum of both sexes and in the ventromedial hypothalamus of females were found to mediate the SIS effect, while vasotocin(VT) levels within the social behavior network remained unchanged. Pharmacological interventions confirmed the critical role of MT in reversing SIS-induced impairments in sociality, flocking behavior, and social recognition, particularly in females. These findings highlight unique nucleus-and sex-dependent variations in MT and VT regulation, providing novel insights into the mechanisms governing avian social behavior. This study advances our understanding of the independent evolutionarypathwaysofneuralcircuitsand neuroendocrine systems that modulate social behaviors across different taxonomic groups.

摘要: Repressor elements significantly influence economically relevant phenotypes in pigs;however, their precise roles and characteristics are inadequately understood. In the present study, we employed H3K27me3 profiling, assay for transposase-accessible chromatin with highthroughput sequencing(ATAC-seq), and RNA sequencing(RNA-seq)data across six tissues derived from three embryonic layers to identify and map 2034 super repressor elements(SREs) and 22223 typical repressor elements(TREs) in the pig genome. Notably, many repressor elements were conserved across mesodermal and ectodermal tissues.SREs exhibited tight regulation of their target genes,affecting a limited number of genes within a specific genomic region with pronounced effects, while TREs exerted broader but weaker regulation over a wider range of target genes. Furthermore, in neuronal tissues, genes regulated by repressor elements started to be repressed during the differentiation of stem cells into progenitor cells.Notably, analysis showed that many repressor elements exhibited cooperative and additive effects on the modulation of KLF4 expression. This research provides the first comprehensive map of pig repressor elements,serving as an essential reference for future studies on repressor elements.

摘要: Pleurostomatid ciliates, as a highly diverse and widely distributed unicellular eukaryote group, play a crucial role in the cycling of nutrients and energy in microbial food webs. However, research on pleurostomatids remains insufficient, resulting in a paucity of molecular information and substantial gaps in knowledge of their phylogenetic relationships. In recent years, we investigated pleurostomatid diversity in various Chinese habitats,including their systematic relationships and taxonomic circumscriptions, which were comprehensively analyzed using an integrative morphomolecular approach. Results revealed that:(1) pleurostomatids can be categorized into two suborders, Protolitonotina subord. nov. and Amphileptina Jankowski, 1967;(2) Protolitonotina subord.nov. represents the ancestral pleurostomatid group and includes two genera, Protolitonotus and Heterolitonotus gen. nov., characterized by right kineties progressively shortened along rightmost full kineties and absence of a left dorsolateral kinety;(3) Heterolitonotus gen. nov.represents an orphan lineage and is defined by an oral slit extending to its dorsal margin;(4) “Protolitonotus clampi”does not group with congeners but instead represents an orphan lineage, thus Novilitonotus gen. nov. is established to which P. clampi is transferred as Novilitonotus clampi comb. nov.;(5) three new species, Apoamphileptus paraclaparedii sp. nov., Heterolitonotus rex gen. nov., sp.nov., and Loxophyllum apohelus sp. nov., are described;and(6) helices 21es6a to 21es6d within the V4 region of small subunit ribosomal RNA(SSU rRNA) may serve as a useful tool for discriminating pleurostomatids. The evolutionary relationships among all main lineages of pleurostomatids are discussed and a key to the identification of pleurostomatid genera is provided.

摘要: The identification of sex chromosomes is fundamental for exploring the mechanism and evolution of sex determination. Platichthys stellatus, a species exhibiting clear sexual dimorphism and homomorphic chromosome pairs, has received limited research concerning its sex determinationmechanisms.Clarifyingthesex chromosome of P. stellatus will enhance our understanding of sex chromosome evolution in Pleuronectiformes. This study employed whole-genome resequencing to investigate the sex chromosome and sex determination system in P. stellatus. Notably, Chr23 was identified as the sex chromosome in P. stellatus, with the sex-determining region(SDR) occupying 48.1% of the chromosome and featuring an XX/XY system. Sex chromosometurnoverwasobservedwithin Pleuronectiformes, with P. stellatus, Verasper variegatus,and Hippoglossus hippoglossus sharing a common ancestral karyotype. No inversions were detected within the SDR of P. stellatus, although chromosomal rearrangements between sex chromosomes and autosomes were identified. Additionally, a sex-specific marker for P. stellatus was ascertained, enabling genetic sex identification, with significant implications for improving breeding programs and aquaculture practices.

摘要: Previous research has highlighted the significant role of progestins and glucocorticoids in fish oocyte maturation and ovulation. To clarify the molecular mechanisms underlying these processes, comprehensive investigations were conducted using a cyp17a2 mutant Nile tilapia（Oreochromis niloticus） model. Analysis revealed pronounced Cyp17a2 expression in ovarian somatic cells of the tilapia. Female cyp17a2-deficient mutants exhibited markedly reduced levels of 17,20β-dihydroxy-4-pregnen-3-one（DHP） and cortisol/cortisone, leading to delayed meiotic initiation and impaired oocyte maturation and spawning. Notably, supplementation with human chorionic gonadotrophin（hCG）, DHP, and cortisol effectively induced germinal vesicle breakdown（GVBD） and facilitated oocyte release with follicular cell layers in cyp17a2^-/-females. Additionally, cyp17a2-/-and rescued cyp17a2-/-females showed elevated transcription of steroidogenic enzymes involved in 17β-estradiol（E2）production compared to spawning wild-type females.Moreover, the reduction in Akt phosphorylation observed in cyp17a2-deficient females and upon inhibitor treatment impaired hCG-induced oocyte maturation. Conversely,activation of the phosphoinositide 3-kinase/protein kinase B（PI3K-Akt） signaling pathway partially rescued the oocyte maturation impairment caused by cyp17a2mutation. Overall, these findings provide functional evidence supporting the critical role of Cyp17a2 in DHP and cortisol biosynthesis, which, in turn, facilitates oocyte maturation and ovulation through activation of the PI3K-Akt signaling pathway in fish.

摘要: DNA methylation at non-CG dinucleotides(mCH, H=A, C,T) widely occurs and plays an important role in specific cell types, including pluripotent, neural, and germ cells.However, the functions and regulatory mechanisms of mCH, particularly in species other than humans and mice,remain inadequately explored. In this study, we analyzed the distribution of mCH across different bovine tissues,identifying significantly elevated mCH levels in bovine embryonic stem cells(bESCs), as well as brain, spleen,and ileum tissues compared to other tissues. Marked differences in mCH patterns between somatic cells and bESCs were observed, reflecting distinct base preferences and the differential expression of DNA methyltransferases.We also identified exon methylation in both CG and nonCG contexts, resembling gene-associated methylation patterns observed in plants. To characterize tissue-specific variations in mCH, we developed a novel method for differential mCH analysis. Results indicated that mCH is not randomly distributed but tends to be enriched in tissuespecific functional regions. Furthermore, regression models demonstrated a positional correlation between CG methylation and mCH. This study enhances our understanding of mCH distribution and function in bovine somatic and stem cells, providing new insights into its potential roles across species and tissues. These findings advance knowledge of epigenetic mechanisms, shedding light on the potential involvement of mCH in development and disease processes.

摘要: Long non-coding RNAs(lncRNAs), which are RNA molecules longer than 200 nucleotides that do not encode proteins, are implicated in a variety of biological processes,including growth and development. Despite research into the role of lnc RNAs in skeletal muscle development, the regulatory mechanisms governing ovine skeletal muscle development remain unclear. In this study, we analyzed the expression profiles of lnc RNAs in skeletal muscle from 90-day-old embryos(F90), 1-month-old lambs(L30), and 3-year-old adult sheep(A3Y) using RNA sequencing. In total, 4738 lnc RNAs were identified, including 997 that were differentially expressed. Short-time series expression miner analysis identified eight significant expression profiles and a subset of lnc RNAs potentially involved in muscle development. Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that the predicted target genes of these lnc RNAs were primarily enriched in pathways associated with muscle development, such as the c AMP and Wnt signaling pathways. Notably, the expression of lnc RNA GTL2 was found to decrease during muscle development. Moreover, GTL2 was highly expressed during the differentiation of skeletal muscle satellite cells(SCs) and was shown to modulate ovine myogenesis by affecting the phosphorylation levels of PKA and CREB. Additionally, GTL2 was found to regulate both the proliferation and differentiation of SCs via the PKACREB signaling pathway. Overall, this study provides a valuable resource and offers novel insights into the functional roles and regulatory mechanisms of lnc RNAs in ovine skeletal muscle growth and development.