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The article discusses a unique adaptation observed in the larvae of the Taiwanese tree frog Kurixalus eiffingeri. The larvae, which live in small water pools on plants, do not seem to defecate until metamorphosis. This behavior is hypothesized to be a sanitation strategy to avoid ammonia contamination in their closed aquatic environment. The study demonstrates reduced ammonia excretion and increased ammonia tolerance in K. eiffingeri larvae compared to other pond-living frog larvae. The findings highlight the close relationship between an organism's habitat and its mode of nitrogen excretion. [Extracted from the article]

Ants occupy huge biomass in the terrestrial ecosystem. Several ant species are highly aggressive and equipped with venomous stingers and/or formic acid. Therefore, ants are abundant but potentially unpalatable prey for some predators. So far, however, the role of ants as prey is not well understood. In this study, we focused anurans (frogs and toads) as one of the major predators of terrestrial arthropods. Using two anuran species and three ant species sharing the habitats, we asked two questions. First, we hypothesized that the anuran preference for prey is ant‐species specific, and tested whether anuran prey preference is affected by ant aggressiveness. Second, we hypothesized that the anurans may innately avoid aggressive ants. To test this hypothesis, ant‐naïve anuran juveniles (Bufo toad and Rana frog) were reared from tadpoles, and juveniles' preferences for three ant species with variable aggressiveness were tested. The exposure to different ant species showed that anuran juveniles highly avoided aggressive ants (Lasius and Brachyponera) compared to less aggressive ants (Tetramorium). Additionally, ant‐naive juvenile toads avoided the aggressive ants without prior experience. In contrast, ant‐naïve juvenile frogs attacked the most of firstly encountered ants and then learned to avoid the unpalatable ants. These findings suggest that (1) some anurans selectively avoid aggressive ant species, (2) Bufo toads have innate avoidance to some ants, while Rana frogs learn to avoid the unpalatable prey. [ABSTRACT FROM AUTHOR]

Abstract Background Temperature adaptation is one of the most important determinants of distribution and population size of organisms in nature. Recently, quantitative trait loci (QTL) mapping and gene expression profiling approaches have been used for detecting candidate genes for heat resistance. However, the resolution of QTL mapping is not high enough to examine the individual effects of various genes in each QTL. Heat stress-responsive genes, characterized by gene expression profiling studies, are not necessarily responsible for heat resistance. Some of these genes may be regulated in association with the heat stress response of other genes. Results To evaluate which heat-responsive genes are potential candidates for heat resistance with higher resolution than previous QTL mapping studies, we performed genome-wide deficiency screen for QTL for heat resistance. We screened 439 isogenic deficiency strains from the DrosDel project, covering 65.6% of the Drosophila melanogaster genome in order to map QTL for thermal resistance. As a result, we found 19 QTL for heat resistance, including 3 novel QTL outside the QTL found in previous studies. Conclusion The QTL found in this study encompassed 19 heat-responsive genes found in the previous gene expression profiling studies, suggesting that they were strong candidates for heat resistance. This result provides new insights into the genetic architecture of heat resistance. It also emphasizes the advantages of genome-wide deficiency screen using isogenic deficiency libraries.

Abstract Background One of the key characters of social insects is the division of labor, in which different tasks are allocated to various castes. In termites, one of the representative groups of social insects, morphological differences as well as behavioral differences can be recognized among castes. However, very little is known about the neuronal and molecular bases of caste differentiation and caste-specific behavior. In almost all termite species, soldiers play defensive roles in their colonies, and their morphology and behavior are largely different from workers (or pseudergates). Therefore, we predicted that some genes linked to defensive behavior and/or those required for neuronal changes are differentially expressed between workers and soldiers, or during the soldier differentiation, respectively. Results Using the brain and suboesophageal ganglion (SOG) of the damp-wood termite Hodotermopsis sjostedti, we first screened genes specifically expressed in soldiers or during soldier differentiation by the differential display method, followed by quantitative real-time polymerase chain reaction. No distinctive differences in expression patterns were detected between pseudergates and soldiers. In the course of soldier differentiation, however, five genes were found to be up-regulated in brain and/or SOG: 14-3-3epsilon, fibrillin2, beta-tubulin, ciboulot, and a hypothetical protein containing a SAP motif. Some of these genes are thought to be associated with cytoskeletal structure or motor-associated proteins in neuronal tissues. Conclusion The identified five genes could be involved in soldier-specific neuronal modifications, resulting in defensive behaviors in termite soldiers. The temporal expression patterns of these genes were consistent with the neuronal changes during soldier differentiation, suggesting that molecular machineries, in which the identified factors would participate, play important roles in behavioral differentiation of termite soldiers.