Oil-tea (Camellia oleifera) is a woody oil crop whose nectar includes galactose derivatives that are toxic to honey bees. Interestingly, some mining bees of the genus Andrena can entirely live on nectar (and pollen) of oil tea and are able to metabolize these galactose derivatives. We present the first next-generation genomes for five and one Andrena species that are respectively specialized and non-specialized oil-tea pollinators, and combining with published genomes of six other Andrena species which did not visit oil-tea, we performed molecular evolution analyses on genes involved in metabolism of galactose derivatives. Six genes (NAGA, NAGA-like, galM, galK, galT, and galE) involved in galactose derivatives metabolism were identified in the five oil-tea specialized species, but only five (with the exception of NAGA-like) were discovered in the other Andrena species. Molecular evolution analyses revealed that NAGA-like, galK and galT in oil-tea specialized species appeared under positive selection. RNASeq analyses showed that NAGA-like, galK, and galT were significantly up-regulated in the specialized pollinator A. camellia compared to the non-specialized pollinator A. chekiangensis. Our study demonstrated that the genes NAGA-like, galK, and galT had played an important role in the evolutionary adaptation of the oil-tea specialized Andrena species.

Leeches are well-known annelids due to their obligate blood-feeding habits. Some leech species secrete various biologically active substances which have important medical and pharmaceutical value in antithrombotic treatments. In this study, we provide a high quality genome of the Asian buffalo leech (Hirudinaria manillensis), based on which we performed a systematic identification of potential antithrombotic genes and their corresponding proteins. Combining automatic and manual prediction, we identified 21 antithrombotic gene families including fourteen coagulation inhibitors, three platelet aggregation inhibitors, three fibrinolysis enhancers, and one tissue penetration enhancer. A total of 72 antithrombotic genes, including two pseudogenes, were identified and most of their corresponding proteins forming three or more disulfide bonds. Three protein families (LDTI, antistasin, and granulin) have internal tandem repeats containing 6, 10, and 12 conserved cysteines, respectively. We also measured the anticoagulant activities of the five identified hirudins (hirudin_Hman1 ~ hirudin_Hman5). The results showed that three (hirudin_Hman1, hirudin_Hman2, and hirudin_Hman5), but not the remaining two, exhibited anticoagulant activities. Our study provides the most comprehensive collection of antithrombotic biomacromolecules from a leech to date. These results will greatly facilitate the research and application of leech derivatives for medical and pharmaceutical purposes of thrombosis.