| miR-941 is the only human-specific small RNA reported so far.Its emergence in the human lineage may be related to the origination and evolution of the human species.It is expressed preferentially in brain tissues such as the prefrontal lobe,but its role in the maintenance and implementation of cellular structure and function is yet unknown.By Edu essay,we found that overexpression of miR-941 promoted cell proliferation and live cell imaging,immunofluorescence staining and qPCR revealed that miR-941 promoted cell proliferation by regulating mitosis.The overexpression of miR-941 facilitated mitosis by shortening the mitotic phase time duration,thus enhancing the ability of division.The deficiency of miR-941 caused a series of mitotic abnormalities,including prolonged mitotic time and M phase arrest,as well as abnormal mitotic phenotypes such as unipolar and multipolar spindles,centrosome replication and separation disorders,and cytokinesis failure.In addition,an important target gene of miR-941,Aurora B,a key kinase involved in mitotic regulation,showed abnormal distribution pattern in metaphase and delayed degradation in telophase,suggesting that miR-941 might regulate mitosis by affecting Aurora B and its involved regulatory mechanisms.Encephalization including increased brain volume and cortical expansion is the most significant phenotype in human evolution,while the critical cause of severe malformation microcephaly in human brain development is mitotic dysfunctions,therefore further investigation on the involvement of the human specific gene miR-941 in mitotic function may shed light on its contribution to human evolution. |
