The chromosome-scale genome of Kobresia myosuroides sheds light on karyotype evolution and recent diversification of a dominant herb group on the Qinghai-Tibet Plateau.

Kobresia species are common in meadows on the Qinghai-Tibet Plateau. They are important food resources for local livestock, and serve a critical foundation for ecosystem integration. Genetic resources of Kobresia species are scarce. Here, we generated a chromosome-level genome assembly for K. myosuroides (Cyperaceae), using PacBio long-reads, Illumina short-reads, and Hi-C technology. The final assembly had a total size of 399.9 Mb with a contig N50 value of 11.9 Mb. The Hi-C result supported a 29 pseudomolecules model which was in consistent with cytological results. A total of 185.5 Mb (44.89% of the genome) transposable elements were detected, and 26,748 protein-coding genes were predicted. Comparative analysis revealed that Kobresia plants have experienced recent diversification events during the late Miocene to Pliocene. Karyotypes analysis indicated that the fission and fusion of chromosomes have been a major driver of speciation, which complied with the lack of whole-genome duplication (WGD) in K. myosuroides genome. Generally, this high-quality reference genome provides insights into the evolution of alpine sedges, and may be helpful to endemic forage improvement and alpine ecosystem preservation.

Highland adaptation of birds on the Qinghai-Tibet Plateau via gut microbiota.

Highland birds evolve multiple adaptive abilities to cope with the harsh environments; however, how they adapt to the high-altitude habitats via the gut microbiota remains understudied. Here we integrated evidences from comparative analysis of gut microbiota to explore the adaptive mechanism of black-necked crane, a typical highland bird in the Qinghai-Tibet Plateau. Firstly, the gut microbiota diversity and function was compared among seven crane species (one high-altitude species and six low-altitude species), and then among three populations of contrasting altitudes for the black-necked crane. Microbiota community diversity in black-necked crane was significantly lower than its low-altitude relatives, but higher microbiota functional diversity was observed in black-necked crane, suggesting that unique bacteria are developed and acquired due to the selection pressure of high-altitude environments. The functional microbial genes differed significantly between the low- and high-altitude black-necked cranes, indicating that altitude significantly impacted microbial communities' composition and structure. Adaptive changes in microbiota diversity and function are observed in response to high-altitude environments. These findings provide us a new insight into the adaptation mechanism to the high-altitude environment for birds via the gut microbiota. KEY POINTS: • The diversity and function of gut microbiota differed significantly between the low- and high-altitude crane species. • Black-necked crane adapts to the high-altitude environment via specific gut microbiota. • Altitude significantly impacted microbial communities' composition and structure.

Long Non-coding RNA SNHG12, a New Therapeutic Target, Regulates miR-199a-5p/Klotho to Promote the Growth and Metastasis of Intrahepatic Cholangiocarcinoma Cells.

Background: Small nucleolar RNA host gene 12 (SNHG12) is a newly identified long non-coding RNA (lncRNA) whose involvements have been explored in several cancers. Our study aimed to explore the functions of SNHG12 on intrahepatic cholangiocarcinoma (ICC) progression and its interaction with miR-199a-5p and Klotho. Methods: RT-PCR was performed to examine the expressions of SNHG12, miR-199a-5p and Klotho in ICC cells. Cell counting kit-8 (CCK-8), colony formation assays and transwell assays were applied to analyze the proliferation, migration and invasion of ICC cells. Luciferase assays, RIP assays and RNA pull-down assays were carried out to demonstrate the direct binding relationships among SNHG12, miR-199a-5p and Klotho. The xenograft nude models were applied to test the effects of SNHG12 on ICC tumor growth. Results: The expression of SNHG12 and Klotho was distinctly increased in ICC cells, while miR-199a-5p expressions were decreased. Functionally, the silence of SNHG12 inhibited the proliferation and metastasis of ICC cells, while miR-199a-5p overexpression exhibited an opposite result. Mechanistically, Knockdown of SNHG12 significantly suppressed the expressions of miR-199a-5p by sponging it, and then increased Klotho expression. The final in vivo experiments suggested that the silence of SNHG12 distinctly inhibited tumor growth. Conclusion: Our findings indicated that SNHG12 inhibited cell proliferation and metastasis process of ICC cells through modulating the miR-199a-5p/Klotho axis and it is expected to become a potential therapeutic target for ICC.

[Identification and phylogenetic analysis of endophytic fungi isolated from Scrophularia ningpoensis].

The endophytic fungi from root, main stem, branch and leaf of Scrophularia ningpoensis were isolated and identified from Wulong and Chongqing, and the population diversity analysis and phylogenetic analysis were followed. The result indicated that, as to population diversity index, S. ningpoensis from Wulong： leaf>main stem=branch>root, branch from Chongqing>branch from Wulong. Fifty-eight endophytic fungi were obtained, most of which were the pathogens of the plant. Colletotrichum was the prevailing genus, of which C. gloeosporioides and C. boninense were the prevailing strains. Leaf and seedlings might be the main path of infection. Endophytic fungi and pathogen might convert to each other, influenced by such factors as environment, genotype et al.

Functional Genetic Variations at the microRNA Binding-Site in the CD44 Gene Are Associated with Risk of Colorectal Cancer in Chinese Populations.

CD44 as one of the most putative stem cell markers plays a key role in many cellular processes, including cancer cell growth and migration. Functional single nucleotide polymorphisms (SNPs) of CD44 may modulate its gene functions and thus cancer risk. In the current study, we investigated if polymorphisms in the 3'-untranslated region (UTR) of CD44 are associated with increased susceptibility to colorectal cancer (CRC) by conducting a case-control study of 946 CRC patients and 989 cancer-free controls. Three polymorphisms (rs13347C/T, rs10836347C/T, rs11821102G/A) in the 3'-UTR of CD44 were genotyped. We found that the variant genotypes (CT and TT) of rs13347 (adjusted odds ratio (OR)=1.79, 95% confidence interval (CI)=1.50-2.17) increased an individual's susceptibility to CRC, compared with rs13347CC homozygous genotypes. We also found that CRC patients with the CT/TT genotype had a 1.6-fold increased risk for developing advanced (stage III + IV) CRC. Furthermore, functional assays showed that the C to T base change at rs13347C/T disrupts the binding site for the microRNA hsa-mir-509-3p, thereby increasing CD44 transcriptional activity and expression level. These findings suggest that the rs13347C/T in microRNA binding site may be potential biomarkers for genetic susceptibility to CRC.

Laparoscope resection of retroperitoneal ectopic insulinoma: a rare case.

Ectopic insulinoma is a very rare and dormant tumor. Here we report the case of a 79-year-old female who presented with repeated episodes of hypoglycemia and was diagnosed with insulinoma based on laboratory and imaging examinations. Computed tomography and positron emission tomography revealed a tumor in the retroperitoneum under and left of the hepatoduodenal ligament, which was resected successfully using a laparoscopic approach. Pathologic results revealed an ectopic insulinoma, which was confirmed immunohistochemically. Ectopic insulinomas are accompanied by hypoglycemia that can be misdiagnosed as drug- or disease-induced. These tumors are difficult to diagnose and locate, particularly in atypical cases or for very small tumors. Synthetic or targeted examinations, including low blood glucose, elevated insulin, proinsulin, and C-peptide levels, 48-h fasting tests, and relevant imaging methods should be considered for suspected cases of insulinoma. Surgery is the treatment of choice for patients with insulinoma, and laparoscopic resection is a feasible and effective method for select ectopic insulinoma cases.

Rare cause of upper gastrointestinal bleeding owing to hepatic cancer invasion: a case report.

Upper gastrointestinal bleeding refers to bleeding that arises from the gastrointestinal tract proximal to the ligament of Treitz. The primary reason for gastrointestinal bleeding associated with hepatocellular carcinoma is rupture of a varicose vein owing to pericardial hypotension. We report a rare case of gastrointestinal bleeding with hepatocellular carcinoma in a patient who presented with recurrent gastrointestinal bleeding. The initial diagnosis was gastric cancer with metastasis to the multiple lymph nodes of the lesser curvature. The patient underwent exploratory laparotomy, which identified two lesions in the gastric wall. Total gastrectomy and hepatic local excision was then performed. Pathological results indicated that the hepatocellular carcinoma had invaded the stomach directly, which was confirmed immunohistochemically. The patient is alive with a disease-free survival of 1 year since the surgery. Hepatocellular carcinoma with gastric invasion should be considered as a rare cause of upper gastrointestinal bleeding in hepatocellular carcinoma patients, especially with lesions located in the left lateral hepatic lobe. Surgery is the best solution.