Effects of heavy ions (12C6+) on malignant melanoma B16F10 cells.

Background: This study aimed to investigate the effects of heavy ion (12C6+) irradiation on the proliferation, apoptosis, cell cycle, migration, and epithelial-mesenchymal transition (EMT) of B16F10 cells. Methods: The B16F10 cells, which is a malignant melanoma cell line widely used in research, irradiated by 12C6+ and X-ray were detected by Hoechst 33342/propidium iodide double staining, Western blot, flow cytometry, and cell scratch tests to evaluate cell proliferation, expression of apoptosis-related proteins, G2/M phase arrest, cell migration, cell invasion and EMT. Results: Compared with the same physical X-ray dose, 12C6+ could effectively inhibit the proliferation of B16F10 cells, inhibit the expression of B-cell lymphoma-2 (Bcl-2) and cellular-myelocytomatosis viral oncogene (c-Myc), and induce the expression of Bax to promote the apoptosis of B16F10 cells. After 12C6+ irradiation, the B16F10 cells exhibited G2/M phase arrest. B16F10 cells were highly sensitive to 12C6+ irradiation. Moreover, compared with X-ray, the 12C6+ irradiation significantly inhibited the migration of B16F10 cells and inhibited extracellular matrix cleavage, induced E-cadherin expression, enhanced cell adhesion, and further inhibited cell invasion, migration, and EMT. Conclusions: The B16F10 cells were highly radiosensitive to 12C6+. Compared with X-ray, B16F10 cells irradiated by 12C6+ significantly reduced the expressions of matrix metalloproteinases to inhibit extracellular matrix cleavage and, thus, effectively inhibit cell invasion and metastasis. However, although the issue of the different therapeutic effects of heavy ion and X-ray radiotherapy on malignant melanoma was investigated and preliminary research results were obtained, several problems must be further studied.

Characteristics of pup ultrasonic vocalizations and parental behavior responses in midday gerbils (Meriones meridianus).

Ultrasonic vocalizations (USVs) play an important role in parent-infant interactions during the neonatal period of rodents because of the pups' need to be suckled and protected by their parents. However, studies on the effects of USVs on parental care are focused on maternal behavior, and little data on paternal care are available, with especially few investigations in midday gerbils. In this study, we examined the effects of early social deprivation (ED) on offspring due to USVs and parental behavior responses in midday gerbils (Meriones meridianus). The results indicated that the number of USVs in ED gerbils increased on postnatal day nine (40 calls/minute), whereas the number of gerbils in the parental care (PC) group remained high for up to 2 weeks (46.6 calls/minute), before decreasing. The number of USVs and duration of single syllables from postnatal day 3 to 21 in ED pups were significantly lower than those in PC pups. ED increased maternal licking, grooming behavior, and nest-building, but decreased huddling and exploring behavior. Similarly, ED increased paternal behavior, like nest-building, but reduced exploring and self-grooming. Overall, gerbil pups displayed high levels of USVs and various syllable types before weaning. ED significantly reduced the number of USVs and syllable types, but increased maternal licking, grooming, and paternal nest-building behavior.

Differences in the number of oxytocin, vasopressin, and tyrosine hydroxylase cells in brain regions associated with mating among great, midday, and Mongolian gerbils.

Neurotransmitters, such as oxytocin (OT), vasopressin (AVP), and dopamine (DA), within the mesolimbic system have deeply conserved roles in regulating mating-related behaviors. However, comparative studies among monogamous and polygamous animals focus mainly on Microtus; very little research has been done in gerbils. Here, we measured body weight, body length, tail length, serum hormone concentrations, and the immunoreactive (ir)-cells of OT, AVP, and tyrosine hydroxylase (TH) in the brain of the polygamous great gerbil (Rhombomys opimus), midday gerbil (Meriones meridianus), and monogamous Mongolian gerbil (Meriones unguiculatus). Body weight, body length, tail length, and serum AVP concentrations were greater in the great gerbil than in the midday gerbil and Mongolian gerbil. The number of OT and AVP cells in the para ventricular nucleus (PVN) and supra optic nucleus (SON) of the hypothalamus were greater in the Mongolian gerbil than in the great gerbil and midday gerbil. Similarly, the number of TH cells in the PVN, medial preoptic area (MPOA), and ventral tegmental area (VTA) was greater in the Mongolian gerbil than in the great gerbil and midday gerbil. To summarize, the number of OT and AVP cells in the PVN and SON and TH cells in the PVN, MPOA, and VTA in the monogamous Mongolian gerbil are greater than those in the great gerbil and midday gerbil.

Differences in cocaine- and morphine-induced cognitive impairments and serum corticosterone between C57BL/6J and BALB/cJ mice.

Addictive drug exposure is associated with impairments in various cognitive domains. Murine models of drug-induced cognitive impairment have helped to inform research on interventions to attenuate such cognitive diminishment; however, while differences between the drug-induced cognitive impairments exhibited by C57BL/6J and BALB/cJ mice have been observed, they remain unclear. This study measured differences in cognitive behavior performance on the object recognition test (ORT) and social recognition test (SRT) and serum levels of corticosterone (CORT) between C57BL/6J and BALB/cJ mice after 14-day chronic exposure to either cocaine (5 mg/kg) or morphine (3 mg/kg) at a dosage of 10 ml/kg/day. The ORT revealed that cocaine and morphine exposure significantly reduced the discrimination ratio in both C57BL/6J and BALB/cJ mice, exploration time was only reduced in C57BL/6J mice: the exploration times of C57BL/6J mice from the control (p < 0.05), cocaine (p < 0.05), and morphine (p < 0.01) administration groups were significantly less than those of BALB/cJ mice. The SRT demonstrated that drug exposure significantly reduced exploration time (cocaine, p < 0.01; morphine, p < 0.01) and impaired social recognition in C57BL/6J mice. No significant effect in BALB/cJ mice was observed. Serum CORT levels were lower in control C57BL/6J mice than in control BALB/cJ mice (p < 0.05), but no difference was observed after drug administration. In conclusion, changes in object and social learning recognition indicate that C57BL/6J mice are more sensitive than BALB/cJ mice to chronic drug exposure, especially to cocaine; concomitant changes in serum CORT may mediate these effects.

Phylogenetic surveys on the newt genus Tylototriton sensu lato (Salamandridae, Caudata) reveal cryptic diversity and novel diversification promoted by historical climatic shifts.

Global climatic transitions and Tibetan Plateau uplifts are hypothesized to have profoundly impacted biodiversity in southeastern Asia. To further test the hypotheses related to the impacts of these incidents, we investigated the diversification patterns of the newt genus Tylototriton sensu lato, distributed across the mountain ranges of southeastern Asia. Gene-tree and species-tree analyses of two mitochondrial genes and two nuclear genes revealed five major clades in the genus, and suggested several cryptic species. Dating estimates suggested that the genus originated in the early-to-middle Miocene. Under different species delimitating scenarios, diversification analyses with birth-death likelihood tests indicated that the genus held a higher diversification rate in the late Miocene-to-Pliocene era than that in the Pleistocene. Ancestral area reconstructions indicated that the genus originated from the northern Indochina Peninsula. Accordingly, we hypothesized that the Miocene Climatic Transition triggered the diversification of the genus, and the reinforcement of East Asian monsoons associated with the stepwise uplifts of the Tibetan Plateau promoted the radiation of the genus in southeastern Asia during the Miocene-to-Pliocene period. Quaternary glacial cycles likely had limited effects on speciation events in the genus, but mainly had contributions on their intraspecific differentiations.

[Altitudinal patterns of species richness and species range size of vascular plants in Xiaolong- shan Reserve of Qinling Mountain: a test of Rapoport' s rule].

Altitudinal patterns of species richness and species range size and their underlying mechanisms have long been a key topic in biogeography and biodiversity research. Rapoport's rule stated that the species richness gradually declined with the increasing altitude, while the species ranges became larger. Using altitude-distribution database from Xiaolongshan Reverse, this study explored the altitudinal patterns of vascular plant species richness and species range in Qinling Xiaolongshan Reserve, and examined the relationships between species richness and their distributional middle points in altitudinal bands for different fauna, taxonomic units and growth forms and tested the Rapoport's rule by using Stevens' method, Pagel's method, mid-point method and cross-species method. The results showed that the species richness of vascular plants except small-range species showed a unimodal pattern along the altitude in Qinling Xiaolongshan Reserve and the highest proportion of small-range species was found at the lower altitudinal bands and at the higher altitudinal bands. Due to different assemblages and examining methods, the relationships between species distributing range sizes and the altitudes were different. Increasing taxonomic units was easier to support Rapoport's rule, which was related to niche differences that the different taxonomic units occupied. The mean species range size of angiosperms showed a unimodal pattern along the altitude, while those of the gymnosperms and pteridophytes were unclearly regular. The mean species range size of the climbers was wider with the increasing altitude, while that of the shrubs which could adapt to different environmental situations was not sensitive to the change of altitude. Pagel's method was easier to support the Rapoport's rule, and then was Steven's method. On the contrary, due to the mid-domain effect, the results of the test by using the mid-point method showed that the mean species range size varied in a unimodal pattern along the altitude, which didn't support the Rapoport's rule, and because of the scatter-spot impact, the explanatory power of the cross-species method was much lower.

[Vertical patterns of plant species diversity in the Baishuijiang Nature Reserve: explanation of area, climate and boundary constraint].

The linear regression models and variation partitioning method were used to analyze the relative and pure effects of area, climate, and boundary constraint on altitudinal patterns of plant species diversity in the Baishuijiang Natural Reserve. The results showed that diversities of overall plant species and different group species exhibited humped-shaped patterns and the peaks were below the mid-point of the elevation span. The patterns were shaped by all factors together. The explanatory power of water-energy hypothesis for the pattern was the strongest. Area acted as a secondary factor the patterns. Boundary constraint effect was a complementary mechanism to explain the plant species diversity altitudinal patterns in Baishuijiang region. The explanatory powers of boundary constraint for different-range species were clearly different. With the increase of species range, boundary constraint showed an increasingly strong correlation with richness patterns.