To expand the toolbox of imaging in living cells, we have engineered a single-chain variable fragment binding the linear HA epitope with high affinity and specificity in vivo. The resulting probe, called the HA frankenbody, can light up in multiple colors HA-tagged nuclear, cytoplasmic, membrane, and mitochondrial proteins in diverse cell types. The HA frankenbody also enables state-of-the-art single-molecule experiments in living cells, which we demonstrate by tracking single HA-tagged histones in U2OS cells and single mRNA translation dynamics in both U2OS cells and neurons. Together with the SunTag, we also track two mRNA species simultaneously to demonstrate comparative single-molecule studies of translation can now be done with genetically encoded tools alone. Finally, we use the HA frankenbody to precisely quantify the expression of HA-tagged proteins in developing zebrafish embryos. The versatility of the HA frankenbody makes it a powerful tool for imaging protein dynamics in vivo.

Fluctuations of nitrogen isotope ratio of gobiid fish (Isaza) specimens and sediments in Lake Biwa, Japan, during the 20th century Abstract-Nitrogen isotope ratios (␦ 15 N) of sediment and formalin-fixed fish specimens (Isaza fish, Chaenogobius isaza, Tanaka), which had been collected and preserved over 40 yr, were used to provide a new methodology to reconstruct recent eutrophication and historical changes in the nitrogen cycle in Lake Biwa. ␦ 15 N records of Isaza fish collected in the north basin of Lake Biwa, a lake that had been rapidly eutrophicated in the last several decades, showed a rapid increase from the early 1960s to 1980s with an overall amplitude of Ͼ3‰. The same trend was simultaneously observed from that of sedimentary nitrogen. We evaluated several factors controlling ␦ 15

Histone post-translational modifications are key gene expression regulators, but their rapid dynamics during development remain difficult to capture. We applied a Fab-based live endogenous modification labeling technique to monitor the changes in histone modification levels during zygotic genome activation (ZGA) in living zebrafish embryos. Among various histone modifications, H3 Lys27 acetylation (H3K27ac) exhibited most drastic changes, accumulating in two nuclear foci in the 64- to 1k-cell-stage embryos. The elongating form of RNA polymerase II, which is phosphorylated at Ser2 in heptad repeats within the C-terminal domain (RNAP2 Ser2ph), and miR-430 transcripts were also concentrated in foci closely associated with H3K27ac. When treated with α-amanitin to inhibit transcription or JQ-1 to inhibit binding of acetyl-reader proteins, H3K27ac foci still appeared but RNAP2 Ser2ph and miR-430 morpholino were not concentrated in foci, suggesting that H3K27ac precedes active transcription during ZGA. We anticipate that the method presented here could be applied to a variety of developmental processes in any model and non-model organisms.

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ABSTRACT. Recently, primitive-type pottery was discovered in the Russian Far East, China, and Japan. Radiocarbon ages of far earlier than 10,000 BP have been obtained, relating directly or indirectly to the pottery. As an example of these very old 14 C ages for incipient pottery, we report here 14 C ages of charred adhesions on five potsherds and three charred wood fragments that were collected with the archeological artifacts (stone tools from the Chojakubo Culture) in the loam layers at the Odai Yamamoto I site (41°03′44′′N, 140°33′20′′E) in Aomori prefecture, at the northern end of the Japanese main island. The carbonaceous remains on the surface of the potsherds could be ancient food residues or soot from fuel for cooking. These small carbon samples were dated at the Tandetron accelerator mass spectrometry (AMS) 14 C dating facility at Nagoya University, as well as by Beta Analytic Co. Ltd. Except for two charred wood 14 C dates, 7070 ± 40 and 7710 ± 40 BP, all five charred-residue samples and one wood charcoal sample gave older 14 C ages of 12,680-13,780 BP, corresponding to the period of the Chojakubo Culture in Japan. This culture marks the beginning of the Jomon Culture, which is characterized by pottery usage and bow-and-arrow hunting.

Stable (δ13C and δ15N) and radio‐ (14C, 137Cs and 210Pb) isotopes were determined for termites that have been sampled from a dry evergreen forest in Thailand. A wood‐feeding termite, Microcerotermes crassus, was separated from soil‐feeders: Termes propinquus, Termes comis and Dicuspiditermes makhamensis by δ13C and δ15N values. The Termes group in Thailand had less diverse values in δ13C and δ15N than those in Australia, where the feeding habits of the ‘Termes’ group are more diverse. Other soil‐feeding termites produced similar δ13C values, but a larger range in δ15N values. 14C‐percent modern carbon (pMC) values suggest that the soil‐feeding termites used younger carbon than the wood‐feeding termites, and this was consistent with the termites from Cameroon, central Africa. Values of δ13C and 14C‐pMC indicate that surface soil was used by a soil‐feeding termite, D. makhamensis, in making the nest mounds, and deeper soil (10–30 cm) by a fungus‐growing termite, Macrotermes carbonarius. 210Pb and 137Cs were scarcely incorporated into the termites, although 214Pb was recovered from the workers. The results suggest that stable‐ and radioisotopes are useful in the study of detritivorous animals, organic matter decomposition and ecosystem engineering.

Detailed zooplankton records from a 26-cm sediment core with a time resolution of approximately 3-10 years were obtained from Lake Biwa, Japan, to examine the historical variations in the zooplankton community during the 20th century. In the sediments, selected zooplankton remains have fluctuated over the years. Daphnia -large zooplankton herbivores -did not occur from 1900 to 1920, and formed a very minor component of the zooplankton community in the following 30 years, while Bosmina -small zooplankton herbivores -were common during this period. In the mid-1960s, however, when eutrophication was noticeable in this lake, Daphnia numbers increased dramatically and became the dominant zooplankton thereafter. In contrast, Difflugia brevicolla and D. biwae, two amoeboid protozoans that live in connection with the lake bottom environment, occurred abundantly until the late 1950s, but gradually decreased after the mid-1960s. In particular, D. biwae, a species peculiar to this lake, was not found in sediment dated after 1980, suggesting its extinction. These results indicate that the zooplankton community structure changed greatly in the 1960s, and suggest that the eutrophication occurring at this time altered the relative strength of top-down and bottom-up forces on the zooplankton community in Lake Biwa.

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