Aoki K.,Japan National Institute of Advanced Industrial Science and Technology |
Harashima A.,Hayashibara Biochemical Labs Inc. |
Sano M.,Japan National Institute of Advanced Industrial Science and Technology |
Yokoi T.,Hitachi Ltd. |
And 3 more authors.
BMC Molecular Biology | Year: 2010
Background: Postgenomic transcriptome analyses have identified large numbers of noncoding (nc)RNAs in mammalian cells. However, the biological function of long ncRNAs in mammalian cells remains largely unknown. Our recent expression profiling of selected human long ncRNAs revealed that a majority were expressed in an organ-specific manner, suggesting their function was linked to specific physiological phenomena in each organ. We investigated the characteristics and function of ncRNAs that were specifically expressed in the thymus, the site of T-cell selection and maturation.Results: Expression profiling of 10 thymus-specific ncRNAs in 17 T-cell leukemia cell lines derived from various stages of T-cell maturation revealed that HIT14168 ncRNA, named Thy-ncR1, was specifically expressed in cell lines derived from stage III immature T cells in which the neighbouring CD1 gene cluster is also specifically activated. The Thy-ncR1 precursor exhibited complex alternative splicing patterns and differential usage of the 5' terminus leading to the production of an estimated 24 isoforms, which were predominantly located in the cytoplasm. Selective RNAi knockdown of each Thy-ncR1 isoform demonstrated that microfibril-associated glycoprotein 4 (MFAP4) mRNA was negatively regulated by two major Thy-ncR1 isoforms. Intriguingly, the MFAP4 mRNA level was controlled by a hUPF1-dependent mRNA degradation pathway in the cytoplasm distinct from nonsense-mediated decay.Conclusions: This study identified Thy-ncR1 ncRNA to be specifically expressed in stage III immature T cells in which the neighbouring CD1 gene cluster was activated. Complex alternative splicing produces multiple Thy-ncR1 isoforms. Two major Thy-ncR1 isoforms are cytoplasmic riboregulators that suppress the expression of MFAP4 mRNA, which is degraded by an uncharacterized hUPF1-dependent pathway. © 2010 Aoki et al; licensee BioMed Central Ltd.
Yoshida T.,Mukogawa Women's University |
Arii Y.,Mukogawa Women's University |
Hino K.,Hayashibara Biochemical Laboratories Inc. |
Sawatani I.,Hayashibara Biochemical Laboratories Inc. |
And 5 more authors.
Cryo-Letters | Year: 2011
Cysts of Artemia franciscana are known to be extremely tolerant to UV and ionizing radiation, hypoxia, dryness, osmotic pressure, and temperatures. However, when cysts are hydrated, their resistance to extreme environmental conditions is markedly reduced, and they subsequently enter a developmental sequence. The hatching rate of hydrated cysts declined when they were rapidly frozen after a short period of hydration but slow freezing improved hatching rates after 6-h hydration (1.4 g H2 O /g dry wt). We observed that trehalose content in hydrated cysts was greatly reduced up to 6-h time. DSC analysis showed different thermal profiles at two cooling rates, suggesting the formation of a minuscule ice crystal inside the cells. High hatching rates can be obtained from highly hydrated cysts at slow cooling rate. © CryoLetters, firstname.lastname@example.org.