Microtubules are essential for various cellular activities and β-tubulins are the target of benzimidazole fungicides. However, the evolution and molecular mechanisms driving functional diversification in fungal tubulins are not clear. In this study, we systematically identified tubulin genes from 59 representative fungi across the fungal kingdom. Phylogenetic analysis showed that α-/β-tubulin genes underwent multiple independent duplications and losses in different fungal lineages and formed distinct paralogous/orthologous clades. The last common ancestor of basidiomycetes and ascomycetes likely possessed two paralogs of α-tubulin (α1/α2) and β-tubulin (β1/β2) genes but α2-tubulin genes were lost in basidiomycetes and β2-tubulin genes were lost in most ascomycetes. Molecular evolutionary analysis indicated that α1, α2, and β2-tubulins have been under strong divergent selection and adaptive positive selection. Many positively selected sites are at or adjacent to important functional sites and likely contribute to functional diversification. We further experimentally confirmed functional divergence of two β-tubulins in Fusarium and identified type II variations in FgTub2 responsible for function shifts. In this study, we also identified δ-/ε-/η-tubulins in Chytridiomycetes. Overall, our results illustrated that different evolutionary mechanisms drive functional diversification of α-/β-tubulin genes in different fungal lineages, and residues under positive selection could provide targets for further experimental study.

SummaryThe Kin1/Par-1/MARK kinases regulate various cellular processes in eukaryotic organisms. Kin1 orthologs are well conserved in fungal pathogens but none of them have been functionally characterized. Here, we show that KIN1 is important for pathogenesis and growth in two phytopathogenic fungi and that FgKin1 regulates ascospore germination and the localization of Tub1 b-tubulins in Fusarium graminearum.The Fgkin1 mutant and putative FgKIN1 S172A kinase dead (nonactivatable) transformants were characterized for defects in plant infection, sexual and asexual reproduction, and stress responses. The localization of FgKin1 and two b-tubulins were examined in the wild-type and mutant backgrounds. Deletion of FgKIN1 resulted in reduced virulence and defects in ascospore germination and release. FgKin1 localized to the center of septal pores. FgKIN1 deletion had no effect on Tub2 microtubules but disrupted Tub1 localization. In the mutant, Tub1 appeared to be enriched in the nucleolus. In Magnaporthe oryzae, MoKin1 has similar functions in growth and infection and it also localizes to septal pores. The S172A mutation had no effect on the localization and function of FgKIN1 during sexual reproduction.These results indicate that FgKIN1 has kinase-dependent and independent functions and it specifically regulates Tub1 b-tubulins. FgKin1 plays a critical role in ascospore discharge, germination, and plant infection.

Although the multipotency of mesenchymal stem cells (MSCs) makes them an attractive choice for clinical applications, immune modulation is an important factor affecting MSC transplantation. At present, the effect of treatment with MSCs on non‑alcoholic fatty liver disease (NAFLD) has received little attention. In the present study, a compact bone‑derived method was used to isolate mouse MSCs (mMSCs) and a high‑fat diet was used to establish a mouse model of NAFLD. Immunophenotypic features of mMSCs were analyzed using flow cytometry. Paraffin sections were stained with hematoxylin and eosin to assess inflammation and steatosis, and with picrosirius red to assess fibrosis. Spleen leukocytes were analyzed by flow cytometry. The results demonstrated that compact bone‑derived MSC transplantation decreased high‑fat diet‑induced weight gain, expansion of subcutaneous adipose tissue, steatosis, lobular inflammation and liver fibrogenesis. Flow cytometry analysis of spleen leukocytes demonstrated that compact bone‑derived MSC transplantation suppressed the proliferation of cluster of differentiation (CD) 4+ T lymphocytes in the spleen, which had been induced by the high‑fat diet. In conclusion, compact bone‑derived MSCs may exhibit clinical value in the treatment of NAFLD through their capacity to suppress the activation of CD4+ T cells.

Increasing evidence has accrued which indicates that mesenchymal stem cells (MSCs) have a potential clinical value in the treatment of certain diseases. Globally, nonalcoholic steatohepatitis (NASH) is a widespread disorder. In the present study, MSCs were isolated successfully from compact bone and a mouse model of NASH was established as achieved with use of a methionine-choline deficient (MCD) diet. Compact bone-derived MSCs transplantation reduced MCD diet-induced weight loss, hepatic lipid peroxidation, steatosis, ballooning, lobular inflammation and fibrogenesis. It was shown that MSCs treatment hampered MCD diet-induced proliferation of CD4 IFN-γ and CD4IL-6 T spleen cells. In addition, CD4IL-17 lymphocytes that associated with anti-inflammation show little change in MCD as well as in MCD+MSCs splenocytes. We conclude that MSCs may have a potential clinical value upon NASH, through their capacity to suppress activation of CD4 IFN-γ and CD4IL-6 lymphocytes.

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