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Catalytically inactive CRISPR‐Cas13 (dCas13)‐based base editors can achieve the conversion of adenine‐to‐inosine (A‐to‐I) or cytidine‐to‐uridine (C‐to‐U) at the RNA level, however, the large size of dCas13 protein limits its in vivo applications. Here, a compact and efficient RNA base editor (ceRBE) is reported with high in vivo editing efficiency. The larger dCas13 protein is replaced with a 199‐amino acid EcCas6e protein, derived from the Class 1 CRISPR family involved in pre‐crRNA processing, and conducted optimization for toxicity and editing efficiency. The ceRBE efficiently achieves both A‐to‐I and C‐to‐U base editing with low transcriptome off‐target in HEK293T cells. The efficient repair of the DMD Q1392X mutation (68.3±10.1%) is also demonstrated in a humanized mouse model of Duchenne muscular dystrophy (DMD) after AAV delivery, achieving restoration of expression for gene products. The study supports that the compact and efficient ceRBE has great potential for treating genetic diseases. [ABSTRACT FROM AUTHOR]

SUMMARY: As a plant‐specific transcription factor, lateral organ boundaries domain (LBD) protein was reported to regulate plant growth and stress response, but the functional research of subfamily II genes is limited. SlMYC2, a master regulator of Jasmonic acid response, has been found to exhibit high expression levels in fruit and has been implicated in the regulation of fruit ripening and resistance to Botrytis. However, its role in fruit expansion remains unknown. In this study, we present evidence that a subfamily II member of LBD, namely SlLBD40, collaborates with SlMYC2 in the regulation of fruit expansion. Overexpression of SlLBD40 significantly promoted fruit growth by promoting mesocarp cell expansion, while knockout of SlLBD40 showed the opposite result. Similarly, SlMYC2 knockout resulted in a significant decrease in cell expansion within the fruit. Genetic analysis indicated that SlLBD40‐mediated cell expansion depends on the expression of SlMYC2. SlLBD40 bound to the promoter of SlEXPA5, an expansin gene, but did not activate its expression directly. While, the co‐expression of SlMYC2 and SlLBD40 significantly stimulated the activation of SlEXPA5, leading to an increase in fruit size. SlLBD40 interacted with SlMYC2 and enhanced the stability and abundance of SlMYC2. Furthermore, SlMYC2 directly targeted and activated the expression of SlLBD40, which is essential for SlLBD40‐mediated fruit expansion. In summary, our research elucidates the role of the interaction between SlLBD40 and SlMYC2 in promoting cell expansion in tomato fruits, thus providing novel insights into the molecular genetics underlying fruit growth. [ABSTRACT FROM AUTHOR]

Tardigrades, commonly known as water bears, are enigmatic organisms characterized by their remarkable resilience to extreme environments despite their simple and compact body structure. To date, there is still much to understand about their evolutionary and developmental features contributing to their special body plan and abilities. This research provides preliminary insights on the conserved and specific gene expression patterns during embryonic development of water bears, focusing on the species Hypsibius exemplaris. The developmental dynamic expression analysis of the genes with various evolutionary age grades indicated that the mid‐conserved stage of H. exemplaris corresponds to the period of ganglia and midgut development, with the late embryonic stage showing a transition from non‐conserved to conserved state. Additionally, a comparison with Drosophila melanogaster highlighted the absence of certain pathway nodes in development‐related pathways, such as Maml and Hairless, which are respectively the transcriptional co‐activator and co‐repressor of NOTCH regulated genes. We also employed Weighted Gene Co‐expression Network Analysis (WGCNA) to investigate the expression patterns of tardigrade‐specific genes during embryo development. Our findings indicated that the module containing the highest proportion of tardigrade‐specific genes (TSGs) exhibits high expression levels before the mid‐conserved stage, potentially playing a role in glutathione and lipid metabolism. These functions may be associated to the ecdysone synthesis and storage cell formation, which is unique to tardigrades. [ABSTRACT FROM AUTHOR]

Mitochondrial dysfunction is considered to be an important mediator of the pro‐aging process in chronic kidney disease, which is continuously increasing worldwide. Although PTEN‐induced kinase 1 (PINK1) regulates mitochondrial function, its role in renal aging remains unclear. We investigated the association between PINK1 and renal aging, especially through the cGAS‐STING pathway, which is known to result in an inflammatory phenotype. Pink1 knockout (Pink1−/−) C57BL/6 mice and senescence‐induced renal tubular epithelial cells (HKC‐8) treated with H2O2 were used as the renal aging models. Extensive analyses at transcriptomic‐metabolic levels have explored changes in mitochondrial function in PINK1 deficiency. To investigate whether PINK1 deficiency affects renal aging through the cGAS‐STING pathway, we explored their expression levels in PINK1 knockout mice and senescence‐induced HKC‐8 cells. PINK1 deficiency enhances kidney fibrosis and tubular injury, and increases senescence and the senescence‐associated secretory phenotype (SASP). These phenomena were most apparent in the 24‐month‐old Pink1−/− mice and HKC‐8 cells treated with PINK1 siRNA and H2O2. Gene expression analysis using RNA sequencing showed that PINK1 deficiency is associated with increased inflammatory responses, and transcriptomic and metabolomic analyses suggested that PINK1 deficiency is related to mitochondrial metabolic dysregulation. Activation of cGAS‐STING was prominent in the 24‐month‐old Pink1−/− mice. The expression of SASPs was most noticeable in senescence‐induced HKC‐8 cells and was attenuated by the STING inhibitor, H151. PINK1 is associated with renal aging, and mitochondrial dysregulation by PINK1 deficiency might stimulate the cGAS‐STING pathway, eventually leading to senescence‐related inflammatory responses. [ABSTRACT FROM AUTHOR]