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This is the first report of gynandromorphy in Isoptera. An Asian dry-wood termite, Neotermes koshunensis (Shiraki) [Kalotermitidae], possessing both male and female phenotypic characteristics, was found on Okinawa Island, Japan. This deformed individual showed morphological and anatomical hermaphroditism in the abdomen. The right side of the seventh sternite was the female form and contained an ovary, while the left side was the male form and contained a testis. Genotypic analysis revealed that this individual was a genotypic bilateral chimera. These results suggested that the termite was a bilateral gynandromorph with a male left side and a female right side. As reported previously in other insects, double fertilization (by two sperms, one with an X and one with a Y chromosome) of a binucleate egg is the most likely mechanism that generated this genotypic bilateral chimera. N. koshunensis has the ability to reproduce through parthenogenesis, in which the secondary polar body is likely to be used for nuclear phase recovery. If the second polar body in this mechanism has high fertility and healthy embryogenic potential, like an egg nucleus, some of gynandromorphs might be produced by a side effect of parthenogenetic ability. 相似文献
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Aphids often form mutualistic associations with ants, in which the aphids provide the ants with honeydew and the ants defend the aphids from predators. In this paper, we report aphid egg protection by ants as a novel aspect of the deeply interdependent relationship between a tree-feeding aphid and its attendant ant. The ant Lasius productus harbours oviparous females, males, and eggs of the hinoki cypress-feeding aphid Stomaphis hirukawai in its nests in winter. We investigated the behaviour of ants kept with aphid eggs in petri dishes to examine whether the ants recognise the aphid eggs and tend them or only provide a refuge for the aphids. Workers carried almost all of the aphid eggs into the nest within 24 h. The ants indiscriminately tended aphid eggs collected from their own colonies and those from other ant colonies. The ants cleaned the eggs and piled them up in the nest, and egg tending by ants dramatically increased aphid egg survival rates. Starving the ants showed no significant effect on aphid egg survivorship. Without ants, aphid eggs were rapidly killed by fungi. These results suggested that grooming by the ants protected the aphid eggs, at least, against pathogenic fungi. This hygienic service afforded by the ants seems indispensable for egg survival of these aphids in an environment rich in potentially pathogenic microorganisms.Electronic supplementary material Supplementary material is available for this article at and is accessible for authorized users. 相似文献
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In the post-genome-sequencing era, emerging genomic technologies are shifting the paradigm for drug discovery and development.
Nevertheless, drug discovery and development still remain high-risk and high-stakes ventures with long and costly timelines.
Indeed, the attrition of drug candidates in preclinical and development stages is a major problem in drug design. For at least
30% of the candidates, this attrition is due to poor pharmacokinetics and toxicity. Thus, pharmaceutical companies have begun
to seriously re-evaluate their current strategies of drug discovery and development. In that light, we propose that a transport
mechanism-based design might help to create new, pharmacokinetically advantageous drugs, and as such should be considered
an important component of drug design strategy. Performing enzyme- and/or cell-based drug transporter, interaction tests may
greatly facilitate drug development and allow the prediction of drug–drug interactions. We recently developed methods for
high-speed functional screening and quantitative structure–activity relationship analysis to study the substrate specificity
of ABC transporters and to evaluate the effect of genetic polymorphisms on their function. These methods would provide a practical
tool to screen synthetic and natural compounds, and these data can be applied to the molecular design of new drugs. In this
review article, we present an overview on the genetic polymorphisms of human ABC transporter ABCG2 and new camptothecin analogues
that can circumvent AGCG2-associated multidrug resistance of cancer. 相似文献
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