Novel organization of mitochondrial minicircles and guide RNAs in the zoonotic pathogen Trypanosoma lewisi.

Kinetoplastid flagellates are known for several unusual features, one of which is their complex mitochondrial genome, known as kinetoplast (k) DNA, composed of mutually catenated maxi- and minicircles. Trypanosoma lewisi is a member of the Stercorarian group of trypanosomes which is, based on human infections and experimental data, now considered a zoonotic pathogen. By assembling a total of 58 minicircle classes, which fall into two distinct categories, we describe a novel type of kDNA organization in T. lewisi. RNA-seq approaches allowed us to map the details of uridine insertion and deletion editing events upon the kDNA transcriptome. Moreover, sequencing of small RNA molecules enabled the identification of 169 unique guide (g) RNA genes, with two differently organized minicircle categories both encoding essential gRNAs. The unprecedented organization of minicircles and gRNAs in T. lewisi broadens our knowledge of the structure and expression of the mitochondrial genomes of these human and animal pathogens. Finally, a scenario describing the evolution of minicircles is presented.

Historical context, process, and development trends of pediatric thyroid cancer research: a bibliometric analysis.

Objective: At present, the structure of knowledge in the field of childhood thyroid cancer is not clear enough, and scholars lack a sufficient understanding of the developing trends in this field, which has led to a shortage of forward-looking outputs. The purpose of this research is to help scholars construct a complete knowledge framework and identify current challenges, opportunities, and development trends. Methods: We searched the literature in the Web of Science Core Collection database on August 7, 2023 and extracted key information from the top 100 most cited articles, such as the countries, institutions, authors, themes, and keywords. We used bibliometric tools such as bibliometrix, VOSviewer, and CiteSpace for a visualization analysis and Excel for statistical descriptions. Results: The top 100 most cited articles fluctuated over time, and the research was concentrated in European countries, the United States, and Japan, among which scientific research institutions and scholars from the United States made outstanding contributions. Keyword analysis revealed that research has shifted from simple treatment methods for pediatric thyroid cancer (total thyroidectomy) and inducing factors (the Chernobyl power station accident) to the clinical applications of genetic mutations (such as the BRAF and RET genes) and larger-scale genetic changes (mutation studies of the DICER1 gene). The thematic strategy analysis showed an increasing trend towards the popularity of fusion oncogenes, while the popularity of research on traditional treatments and diagnostics has gradually declined. Conclusion: Extensive research has been conducted on the basic problems of pediatric thyroid cancer, and there has been significant outputs in the follow-up and cohort analysis of conventional diagnostic and treatment methods. However, these methods still have certain limitations. Therefore, scholars should focus on exploring fusion genes, the clinical applications of molecular targets, and novel treatment methods. This study provides a strong reference for scholars in this field.

Human-like adrenal features in Chinese tree shrews revealed by multi-omics analysis of adrenal cell populations and steroid synthesis.

The Chinese tree shrew ( Tupaia belangeri chinensis) has emerged as a promising model for investigating adrenal steroid synthesis, but it is unclear whether the same cells produce steroid hormones and whether their production is regulated in the same way as in humans. Here, we comprehensively mapped the cell types and pathways of steroid metabolism in the adrenal gland of Chinese tree shrews using single-cell RNA sequencing, spatial transcriptome analysis, mass spectrometry, and immunohistochemistry. We compared the transcriptomes of various adrenal cell types across tree shrews, humans, macaques, and mice. Results showed that tree shrew adrenal glands expressed many of the same key enzymes for steroid synthesis as humans, including CYP11B2, CYP11B1, CYB5A, and CHGA. Biochemical analysis confirmed the production of aldosterone, cortisol, and dehydroepiandrosterone but not dehydroepiandrosterone sulfate in the tree shrew adrenal glands. Furthermore, genes in adrenal cell types in tree shrews were correlated with genetic risk factors for polycystic ovary syndrome, primary aldosteronism, hypertension, and related disorders in humans based on genome-wide association studies. Overall, this study suggests that the adrenal glands of Chinese tree shrews may consist of closely related cell populations with functional similarity to those of the human adrenal gland. Our comprehensive results (publicly available at http://gxmujyzmolab.cn:16245/scAGMap/) should facilitate the advancement of this animal model for the investigation of adrenal gland disorders.