Physiological function of photoreceptor UVR8 in UV-B tolerance in the liverwort Marchantia polymorpha.

MAIN CONCLUSION: The physiological importance of MpUVR8 in UV-B resistance and translocation in a UV-B-dependent manner from the cytosol into the nucleus is characterized in Marchantia polymorpha. UV RESISTANCE LOCUS 8 (UVR8) is an ultraviolet-B (UV-B) light receptor functioning for UV-B sensing and tolerance in Arabidopsis thaliana and other species. It is unclear whether UVR8 physiologically functions in UV-B-induced defense responses in Marchantia polymorpha, which belongs to the earliest diverging group of embryophyte lineages. Here, we demonstrate that UVR8 has a physiological function in UV-B tolerance and that there is a UVR8-dependent pathway involved. In addition, a UVR8-independent pathway is revealed. We examine the tissue-specific expression pattern of M. polymorpha UVR8 (MpUVR8), showing that it is highly expressed in the apical notch in thalli and gametangiophores, as well as in antheridial and archegonial heads. Furthermore, Mpuvr8KO plant transformants, in which the MpUVR8 locus was disrupted, were produced and analyzed to understand the physiological and molecular function of MpUVR8. Analysis using these plants indicates the important roles of MpUVR8 and MpUVR8-regulated genes, and of MpUVR8-independent pathways in UV-B tolerance. Subcellular localization of Citrine-fused MpUVR8 in M. polymorpha cells was also investigated. It was found to translocate from the cytosol into the nucleus in response to UV-B irradiation. Our findings indicate strong conservation of the physiological function of UVR8 and the molecular mechanisms for UVR8-dependent signal transduction through regulation of gene expression in embryophytes.

Detection of beta-thalassemia/hemoglobin E disease in samples which initially were diagnosed as homozygous hemoglobin E.

BACKGROUND: Differentiation of beta-thalassemia/HbE disease from homozygous HbE in samples containing HbA2/E > 75% and HbF < 15% is difficult. The aim of this study is to observe the possibility of using Hb typing and hematological parameters to identify both disorders. METHODS: Multiplex amplification refractory mutation system (MARMS)-PCR for beta-thalassemia codons 17 (A > T), 41/42 (-TCTT), 71/72 (+A), and IVSI-ntl (G > T) mutations and ARMS-PCR for HbE were performed in 67 samples that contained HbA2/E > 75% and HbF < 15%. RESULTS: Beta-thalassemia/HbE disease was identified in 10 of 67 (14.93%) samples. Levels of hemoglobin, hematocrit, and mean corpuscular volume (MCV) of beta-thalassemia/HbE disease were significantly lower than those of homozygous HbE whereas, levels of HbF were significantly higher. CONCLUSIONS: In places where the molecular analysis is not available, HbF > 5% in combination with MCV < 55 fL, hemoglobin < 100 g/L, and hematocrit < 0.30 L/L could be used for screening of beta-thalassemia/HbE disease.