Probing the processing of facial expressions in monkeys via time perception and eye tracking.

Accurately recognizing facial expressions is essential for effective social interactions. Non-human primates (NHPs) are widely used in the study of the neural mechanisms underpinning facial expression processing, yet it remains unclear how well monkeys can recognize the facial expressions of other species such as humans. In this study, we systematically investigated how monkeys process the facial expressions of conspecifics and humans using eye-tracking technology and sophisticated behavioral tasks, namely the temporal discrimination task (TDT) and face scan task (FST). We found that monkeys showed prolonged subjective time perception in response to Negative facial expressions in monkeys while showing longer reaction time to Negative facial expressions in humans. Monkey faces also reliably induced divergent pupil contraction in response to different expressions, while human faces and scrambled monkey faces did not. Furthermore, viewing patterns in the FST indicated that monkeys only showed bias toward emotional expressions upon observing monkey faces. Finally, masking the eye region marginally decreased the viewing duration for monkey faces but not for human faces. By probing facial expression processing in monkeys, our study demonstrates that monkeys are more sensitive to the facial expressions of conspecifics than those of humans, thus shedding new light on inter-species communication through facial expressions between NHPs and humans.

Inhibition of Notch signaling pathway enhanced the radiosensitivity of breast cancer cells.

This study aimed to investigate the effect of inhibiting the Notch signaling pathway on the radiosensitivity of breast cancer cells. Human breast cancer cell lines (MCF-7 and T47D) were selected and treated with radiation of different doses. Cells were treated with Gamma secretase inhibitor (GSI) to analyze the effects of GSI on the Notch signaling, which were detected by Immunofluorescence assay, RT-qPCR, and Western blot analysis. Besides, Transwell assay, Scratch test, colony formation assay, MTT assay, and flow cytometry were conducted to show the effects of GSI on the invasion and migration, survival fraction, cell viability, and apoptosis of MCF-7 and T47D cells after radiation therapy. Moreover, cell transfection with a dominant negative mutant of RBPJ, the key transcription factor of Notch signaling pathway, were also applied to show the inhibition of Notch signaling pathway. Initially, we found that the 4 Gy radiation activated Notch signaling pathway, and enhanced the invasion and migration of MCF-7 and T47D cells. However, GSI inhibited the Notch signaling pathway, and reversed the enhancement of radiation on the migration and invasion, promoted the enhancement of apoptosis and inhibition of proliferation of MCF-7 and T47D cells induced by radiation. Except that, we also determined that GSI and dnRBPJ suppressed the upregulation of Notch signaling after radiation therapy. Our study demonstrated that inhibition of the Notch signaling pathway enhanced the radiosensitivity of breast cancer cells, which may provide evident for a beneficial adjuvant therapy in the breast cancer treatment.

Akr1 attenuates methylmercury toxicity through the palmitoylation of Meh1 as a subunit of the yeast EGO complex.

BACKGROUND: We previously reported that palmitoyltransferase activity of Akr1 is required for alleviation of methylmercury toxicity in yeast. In this study, we identified a factor that alleviates methylmercury toxicity among the substrate proteins palmitoylated by Akr1, and investigated the role of this factor in methylmercury toxicity. METHODS: Gene disruption and site-directed mutagenesis were used to examine the relationship of methylmercury toxicity and vacuole function. Palmitoylation was investigated using the acyl-biotinyl exchange method. Vacuoles were stained with the fluorescent probe FM4-64. RESULTS: We found that Meh1 (alias Ego1), a substrate protein of Akr1, participates in the alleviation of methylmercury toxicity. Moreover, almost no palmitoylation of Meh1 when Akr1 was knocked out, and mutant Meh1, which is not palmitoylated, did not show alleviation of methylmercury toxicity. The palmitoylated Meh1 was involved in the alleviation of methylmercury toxicity as a constituent of EGO complex which suppresses autophagy. Methylmercury caused vacuole deformation, and this was greater in the yeasts knocking out the EGO complex subunits. 3-Methyladenine, an autophagy inhibitor, suppresses vacuole deformation and cytotoxicity caused by methylmercury. The elevated methylmercury sensitivity by Meh1 knockout almost completely disappeared in the presence of 3-methyladenine. CONCLUSIONS: Akr1 reduces methylmercury toxicity through palmitoylation of Meh1. Furthermore, the EGO complex including Meh1 reduces methylmercury toxicity by suppressing the induction of vacuole deformation caused by methylmercury. GENERAL SIGNIFICANCE: These findings propose that Meh1 palmitoylated by Akr1 may act as a constituent of the EGO complex when contributing to the decreased cytotoxicity by negatively controlling the induction of autophagy by methylmercury.

[Effects of UV-B radiation on the decomposition of Cunninghamia lanceolata leaf litter].

A litterbag experiment was conducted to study the decomposition of Cunninghamia lanceolata leaf litter under ambient and reduced UV-B radiation (22.1% below ambient). Comparing with ambient treatment, the reduced treatment decreased the decomposition rate of C. lanceolata leaf litter by 69.6% (P<0.001), making the relative contents of nitrogen (N), phosphorus (P), and lignin in the litter increased by 150%, 83.3%, and 13.8%, respectively, and the release of potassium (K) and carbon (C) slowed down. In the process of litter decomposition, photo-degradation of lignin didn't play crucial role. The results suggested that UV-B radiation could accelerate the decomposition rate of C. lanceolata leaf litter, promote the release of N, P, K, and C from it, and increase the nutrients turnover rate in litter layer as well as the carbon flux on the ground, giving potential effects on the function of C. lanceolata forest as a carbon source or sink in humid subtropical China.

[Characteristics of soil seed banks in logging gaps of forests at different succession stages in Changbai Mountains].

An investigation was made on the soil seed banks in the logging gaps of Populus davidiana--Betula platyphylla secondary forest, secondary broad-leaved forest, and broad-leaved Korean pine mixed forest at their different succession stages in Changbai Mountains. Among the test forests, secondary broad-leaved forest had the highest individual density (652 ind x m(-2)) in its soil seed bank. With the succession of forest community, the diversity and uniformity of soil seed bank increased, but the dominance decreased. The seed density of climax species such as Pinus koraiensis, Abies nephrolepis, and Acer mono increased, whereas that of Maackia amurensis and Fraxinus mandshurica decreased. Moreover, the similarity in species composition between soil seed bank and the seedlings within logging gaps became higher. The individual density and similarity between soil seed bank and the seedlings in non-logging gaps were similar to those in logging gaps. All of these indicated that soil seed bank provided rich seed resources for forest recovery and succession, and the influence of soil seed bank on seedlings regeneration increased with the succession.