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Temporary freshwater rock pools, as special, small-sized and isolated habitats, provide ideal systems for studying island biogeography and ecological theories and processes. In this study, a total of 70 potholes of mountain rivers were sampled during the four seasons from November 2013 to October 2014 to assess the structure of the benthic invertebrate community and to identify the relationships between habitat characteristics and the community composition. Pothole area ranged from approximately 0.01 to 0.39 m², and pothole depth ranged from 0.03 to 0.74 m. Forty-three taxa belonging to 37 families and 16 orders were collected from the potholes. The highest numbers of benthic invertebrate taxa were observed in summer and the highest average number of taxa per pothole (8.5) was observed in autumn. The diversity was the highest in spring, and the average densities of benthic invertebrates were highest in autumn. Large potholes supported more taxa than small ones and significant relationships between richness and pothole area, richness and water volume were observed. The results of Redundancy Analysis show that the community composition of benthic invertebrates in the potholes was closely correlated with water temperature, pothole area and water depth. Our results indicate that benthic invertebrate communities in river potholes are mainly structured by water depth, pothole area and water volume. The seasonal changes are also an important factor determining the presence/absence of certain taxa.
Somatic cell nuclear transfer (SCNT) is currently the most efficient and precise method to generate genetically tailored pig models for both agricultural and biomedical research. However, its efficiency is crucially dependent on the source of nuclear donor cells. In this study, we compared the cloning efficiency by using three lines of donor cells that are derived from fetal, newborn and adult fibroblasts of Chinese indigenous Meishan pig. We showed that cleavage rate and blastocyst formation rate of the reconstructed embryos were not significantly different between the fetal (80.7% and 15.6%) and newborn ear skin (77.5% and 12.3%) fibroblast groups (p>0.05), but in both groups these indices were significantly higher than that found in the adult ear skin (70.5% and 8.8%; p<0.05). Reconstructed embryos derived from fetal, newborn, and adult ear skin fibroblasts were transferred to four surrogates, respectively. For the fetal, newborn, and adult ear skin fibroblasts, the number of pregnancies were two (50.0%), two (50.0%), and one (25.0%), respectively, and the number of deliveries were two (50.0%), one (25.0%), and zero (0.0%), respectively. Seven and two cloned piglets were obtained from the fetal and newborn ear skin fibroblasts respectively, while no piglets were obtained from the adult ear skin fibroblasts. Two cloned piglets from the newborn ear skin fibroblasts died shortly after birth because of neonatal asphyxia caused by dystocia. The birth weights of the piglets derived from the fetal and newborn ear skin fibroblasts were 1230.5 and 1310.0g, respectively, which were statistically insignificant (p>0.05), but both were significantly higher than that of the control groups (p<0.05). Microsatellite analyses demonstrated that the genotypes of all cloned piglets were identical to their donor cells. Therefore, cloned pigs were successfully produced using two sources of donor cells isolated from the fetal and newborn ear skin fibroblasts of Meishan piglet, and indicating a better cloning efficiency than that obtained from adult fibroblasts. We concluded that the nuclear donor cell lines have significant impact on the developmental competence of cloned embryos as well as on the cloning efficiency of Meishan pig.
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