GhVLN4 exhibited activity of cross-linking actin filaments into bundles. Overexpression of GhVLN4 increased the abundance of thick actin bundles and resulted in longer cell phenotypes. Actin bundle is a dynamic, higher-order cytoskeleton structure that is essential for cell expansion. Villin is one of the major proteins responsible for crosslinking actin filaments into bundles. However, this kind of actin binding protein has rarely been investigated in cotton. In the present work, a cotton villin gene was molecularly cloned from Upland cotton and denominated as GhVLN4. This gene was more highly expressed in fiber-bearing wild-type cotton TM-1 (Texas Marker-1) than in Ligon lintless-1 mutant (Li-1). Biochemical analysis combined with subcellular localization revealed that GhVLN4 is an actin-binding protein performing actin filament bundling activity in vitro. In line with these findings, a greater abundance of thick actin filament bundles were observed in GhVLN4-overexpressing transgenic plants compared with those in wild-type control. Moreover, ectopic expression of GhVLN4 significantly enhanced the cell length-width ratio of Schizosaccharomyces pombe yeast and increased the length of various Arabidopsis cells, including root cells, root hairs and pollen tubes. Taken together, our results demonstrate that GhVLN4 is involved in the generation of actin filament bundles, suggesting that GhVLN4 may play important roles in regulating plant cell morphogenesis and expansion by remodeling actin cytoskeleton.

BackgroundMethylmalonic acidemia (MMA) is an autosomal recessive inherited disorder caused by complete or partial deficiency of the enzyme methylmalonyl-CoA mutase (mut0 enzymatic subtype or mut– enzymatic subtype, respectively); a defect in the transport or synthesis of its cofactor, adenosyl-cobalamin (cblA, cblB, or cblD-MMA); or deficiency of the enzyme methylmalonyl-CoA epimerase. The cblA type of MMA is very rare in China. This study aimed to describe the biochemical, clinical, and genetic characteristics of two siblings in a Chinese family, suspected of having the cblA-type of MMA.MethodsThe Chinese family of Han ethnicity of two siblings with the cblA-type of MMA, was enrolled. Target-exome sequencing was performed for a panel of MMA-related genes to detect causative mutations. The influence of an identified missense variant on the protein’s structure and function was analysed using SIFT, PolyPhen-2, PROVEAN, and MutationTaster software. Moreover, homology modelling of the human wild-type and mutant proteins was performed using SWISSMODEL to evaluate the variant.ResultsThe proband was identified via newborn screening (NBS); whereas, her elder brother, who had not undergone expanded NBS, was diagnosed later through genetic family screening. The younger sibling exhibited abnormal biochemical manifestations, and the clinical performance was relatively good after treatment, while the older brother had a mild biochemical and clinical phenotype, mainly featuring poor academic performance. A novel, homozygous missense c.365T>C variant in exon 2 of their MMAA genes was identified using next-generation sequencing and validated by Sanger sequencing. Several different types of bioinformatics software predicted that the novel variant c.365T>C (p.L122P) was deleterious. Furthermore, three-dimensional crystal structure analysis revealed that replacement of Leu122 with Pro122 led to the loss of two intramolecular hydrogen bonds between the residue at position 122 and Leu188 and Ala119, resulting in instability of the MMAA protein structure.ConclusionsThe two siblings suspected of having the cblA-type of MMA showed mild phenotypes during follow-up, and a novel, homozygous missense variant in their MMAA genes was identified. We believe that the clinical features of the two siblings were associated with the MMAA c.365T>C variant; however, further functional studies are warranted to confirm the variant’s pathogenicity.Electronic supplementary materialThe online version of this article (10.1186/s12881-018-0635-4) contains supplementary material, which is available to authorized users.

The association between the gut microbiome and the five stages of colorectal cancer (CRC) (healthy, polyposis, nonadvanced adenoma, advanced adenoma, and cancer) remains unclear. We performed 16S rRNA sequencing of the V3-V4 amplicon from 999 samples from subjects at various stages of CRC development and constructed an accurate predictive random forest model for CRC development. In the testing set, our five-category CRC prediction classifier had accuracies of 0.84 and 0.74 using the relative operational taxonomic unit (OTU) abundances and relative genus abundances, respectively. Specifically, the OTU-based classifier had a sensitivity of 0.97 and specificity of 0.97 for CRC samples, and the genus-based classifier had a sensitivity of 0.97 and specificity of 0.95 for CRC samples. Meanwhile, the gut microbiota was found to differ at all stages of CRC development. The differential abundances of closely related bacteria were used to accurately classify the five stages of CRC development. Additionally, both unannotated and annotated OTUs played important roles in classifier modelling. Our work not only provides valuable 16S rRNA sequencing data from patients and healthy individuals on a large scale but also identifies reproducible gut microbiome biomarkers for CRC staging and highlights their potential applications as noninvasive microbiome biomarkers for diagnosis and as predictive CRC screening tests.