Effect of azadirachtin-derived decalin (perhydronaphthalene) and dihydrofuranacetal (furo[2, 3-fo]pyran) fragments on the feeding behaviour of Spodoptera littoralis

Decalin and dihydrofuranacetal fragments related to those in azadirachtin exhibited antifeedant activity against larvae of the African leaf-worm Spodoptera littoralis. Boisd. All the decalin fragments tested were methoxy (C11) derivatives of azadirachtin. The most active decalin fragment had a ketone substitution at C7. Overall, the compounds were more active when tested in combinations of one decalin fragment and one dihydrofuranacetal fragment than when tested singly. Although some of these combinations did show significant levels of antifeedant activity, sometimes coupled with a synergistic effect, they were not as active as either azadirachtin or dihydroazadirachtin.     

Knockout of targeted gene in porcine somatic cells using zinc‐finger nuclease

Targeted genome editing is a widely applicable approach for efficiently modifying any sequence of interest in animals. It is very difficult to generate knock‐out and knock‐in animals except for mice up to now. Very recently, a method of genome editing using zinc‐finger nucleases (ZFNs) has been developed to produce knockout rats. Since only injection of ZFNs into the pronuclear (PN) embryo is required, it seems to be useful for generating gene‐targeted animals, including domestic species. However, no one has reported the successful production of knockout pigs by direct injection of ZFNs into PN embryos. We examined whether ZFN works on editing the genome of porcine growth hormone receptor in two kinds of cell lines (ST and PT‐K75) derived from the pig as a preliminary study. Our data showed that pZFN1/2 vectors were efficiently transfected into both ST and PT‐K75 cells. In both cell lines, results from Cel‐I assay showed that modification of the targeted gene was confirmed. We injected ZFN1/2 mRNAs into the nucleus of PN stage embryos and then they were transferred to the recipients. However, pups were not delivered. Taken together, ZFN can be an available technology of genome editing even in the pig but further improvement will be required for generating genome‐modified pigs.     

澳大利亚的杜鹃及其寄生适应性(英文)

长期以来,人们一直对寄生性繁殖的杜鹃所采用的种种计谋惊叹不已。本文对澳大利亚的寄生杜鹃如何增加寄生巢的可获得性、如何寻找和接近巢以及如何让宿主接受它们的寄生卵与雏鸟进行了综述。这些杜鹃所采用的对策,有一些是世界上其他杜鹃种类也采用的,但有一些对策,如产隐蔽的卵和模拟的雏鸟,却似乎仅见于澳大利亚的杜鹃。泛性寄生的杜鹃因为要应对较多种类的宿主,难度自然远大于专一性寄生的杜鹃种类,这同时也解释了为什么不同种类的杜鹃进化出不同的寄生策略,以避免不同宿主的识别。     

Vitrification procedure decreases inositol 1,4,5‐trisphophate receptor expression,resulting in low fertility of pig oocytes

Although cryopreservation of mammalian oocytes is an important technology, it is well known that unfertilized oocytes, especially in pigs, are highly sensitive to low temperature and that cryopreserved oocytes show low fertility and developmental ability. The aim of the present study was to clarify why porcine in vitro matured (IVM) oocytes at the metaphase II (MII) stage showed low fertility and developmental ability after vitrification. In vitro matured cumulus oocyte complexes (COCs) were vitrified with Cryotop and then evaluated for fertility through in vitro fertilization (IVF). Although sperm‐penetrated oocytes were observed to some extent (30–40%), the rate of pronuclear formation was low (9%) and none of them progressed to the two‐cell stage. The results suggest that activation ability of cryopreserved oocytes was decreased by vitrification. We examined the localization and expression level of the type 1 inositol 1,4,5 trisphosphate receptor (IP₃R1), the channel responsible for Ca²⁺ release during IVF in porcine oocytes. Localization of IP₃R1 close to the plasma membrane and total expression level of IP₃R1 protein were both decreased by vitrification. In conclusion, our present study indicates that vitrified‐warmed porcine COCs showed a high survival rate but low fertility after IVF. This low fertility seems to be due to the decrease in IP₃R1 by the vitrification procedure.