In animal development, the mechanisms by which localized factors and organelles in egg cytoplasm were exactly distributed into each daughter cell are essential for formation of various cell types. During ascidian Halocynthia roretzi embryogenesis, ooplasmic mitochondria were mainly segregated into muscle and neural precursor cells. At the 32-cell stage, localized mitochondria in the B6.2 blastomeres were preferentially distributed into the B7.4 muscle precursors compared with the B7.3 mesenchyme/ notochord precursors. When the B6.2 blastomeres were isolated from the early 32-cell stage embryos and then allowed to divide 2 times of cell division, the resultant partial embryos showed symmetric distribution of mitochondria, and the partial embryos were composed of equal size cells. In normal development, cell fates of the B7.3 blastomere were correlated with the unequal cleavage of B6.2 lineage cells that normally occurs in the next two-cell division stages to produce a large B8.5 mesenchyme and a small B8.6 notochord cell. Mitochondria are distributed asymmetrically in both cells. When embryos were treated with FGF receptor inhibitor SU5402 and MEK inhibitor U0126 between the 32-cell and the early 64-cell stages, the resultant embryos showed equal cleavage pattern and symmetric distribution of mitochondria in daughter cells of the B6.2 blastomeres. However, blocking of Nodal and Notch signaling did not affect the cell division pattern and mitochondrial distribution in the B6.2 lineage blastomeres between the 32-cell and 110-cell stages. Therefore, it is likely that FGF/MEK signaling is involved in asymmetric distribution of mitochondria and unequal cleavage of the B6.2 lineage blastomeres in ascidian embryo.
Anthocyanins are very important constituent of human diet. In recent years, they have gained much attention due to their antioxidative properties. As the radish (Raphanus sativus L) has rich content of anthocyanins, the study is aimed to develop increased functional radish from selected radish varieties. ‘Bordeux’ is a hybrid variety of breeding between one accession derived from ‘Oharu’ as a maternal variety and ‘Chungpihongsim’ as a paternal variety. In this study, we investigated the new varieties of radish commonly consumed in Republic of Korea for their total phenolic content (TPC) and antioxidant activities using three (DDPH, FRAP and CUPRAC) different assays. The selected radish varieties like ‘Bordeux’, ‘Chungbok’, ‘3209’, ‘Chungwoon’, ‘Oharu’, and ‘Chungpihongsim’ were procured from the company Syngenta Korea. Among the selected radish varieties, ‘Bordeux’ (289 μg/g FW) and ‘Chungpihongsim’ (276 μg/g FW) revealed maximum amount of phenolics; whereas ‘3209’ (103 μg/g FW) and ‘Chungwoon’ (166 μg/g FW) showed the lower amount of phenolics content, respectively. Extracts from these studied radishes showed good to moderate antioxidant activities. The varieties ‘Chungpihongsim’ and ‘Bordeux’ revealed maximum antioxidant activity for all assays as demonstrated. However, some varieties like ‘3209’ and ‘Oharu’ exhibited the lowest antioxidant activity in all the tested assays, viz; DPH, FRAP and CUPRAC in μg TE/g FW, respectively. The antioxidant activities may be attributed to the higher phenolic acid contents as a linear relation was observed between the two components and the antioxidant parameters.