In the precedent research conducted by the same team, it concluded that the activities in C-type natriuretic peptide (CNP)/cyclic guanosine monophosphate (cGMP)/cyclic adenosine monophosphate (cAMP)/β-type phospholipase C (PLCβ) pathways of rat antral smooth muscle were changed due to diabetes, which was the key pathogenetic mechanism for diabetic gastric dysmotility. As the follow-on step, this study was designed to probe into the downstream signaling pathway of CNP/PLCβ. The results showed that level of α-type protein kinase C (PKCα),cell membrane to cytoplasm ratio of PKCα, cell membrane to cytoplasmic ratio of βI-type protein kinase C (PKCβI) and level of Phosphor-PKCα (P-PKCα) were significantly reduced in diabetes rat antral smooth muscle samples. The content of tetraphosphate inositol (IP4) in gastric antral smooth muscle of diabetic rats reduced, and the content of diacyl-glycerol (DG) was unchanged. CNP significantly decreased the content of IP4 and DG, this effect was more obvious in diabetic rats. Subsequent to the addition of protein kinase A (PKA) blocker N-[2- (p-Bromocin-namylamino)ethyl]-5 -isoquinolinesulfonamide dihydrochloride (H-89) before CNP treatment, the inhibitory effect of CNP was reduced; subsequent to the addition of protein kinase G (PKG) blocker KT5823 before CNP treatment, the inhibitory effect of CNP was also reduced. With the addition of the combination of H-89 and KT5823 before CNP treatment, the inhibition by CNP could be offset. These results were concluded that CNP inhibited the activity of PKC family in rat smooth muscle and reduced the levels of IP4 and DG through the PKG/PKA-PLCβ pathways, causing inhibited muscular contractions, which may be a key pathogenetic factor for diabetic gastroparesis.
Aphis gossypii Glover (Hemiptera: Aphididae) is a serious pest of cotton in northern China. A microsatellite analysis was used to characterize the genetic structure of A. gossypii populations from different geographic, host plant, and seasonal populations in 2014. Among 906 individuals, 507 multilocus genotypes were identified, with genotypic richness values of 0.07–1.00 for the populations. We observed moderate levels of genetic differentiation among geographic populations (FST = 0.103; 95% confidence interval: 0.065–0.145) and host plant populations (FST = 0.237; 95% confidence interval: 0.187–0.296). A Mantel test of isolation by distance revealed no significant correlations between Slatkin’s linearized FST and the natural logarithm of geographic distance. A Bayesian analysis of population genetic structures identified three clusters. An analysis of molecular variance revealed significant differences among the three clusters (F = 0.26596, P < 0.0001), among seasons (F = 0.04244, P = 0.00381), and among host populations (F = 0.12975, P = 0.0029). Thus, the A. gossypii populations in northern China exhibit considerable genotypic diversity. Additionally, our findings indicated that the 31 analyzed populations could be classified as one of three host biotypes (i.e., cotton, cucumber, and pomegranate biotypes). There were also clear seasonal effects on population genetic structure diversity among aphids collected from Anyang. 相似文献
The cotton-melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is a polyphagous species with a worldwide distribution and a variety of biotypes. North China is a traditional agricultural area with abundant winter and summer hosts of A. gossypii. While the life cycles of A. gossypii on different plants have been well studied, those of the biotypes of North China are still unclear.
Results
Host transfer experiments showed that A. gossypii from North China has two host-specialized biotypes: cotton and cucumber. Based on complete mitochondrial sequences, we identified a molecular marker with five single-nucleotide polymorphisms to distinguish the biotypes. Using this marker, a large-scale study of biotypes on primary winter and summer hosts was conducted. All A. gossypii collected from three primary hosts—hibiscus, pomegranate, and Chinese prickly ash—were cotton biotypes, with more cotton-melon aphids found on hibiscus than the other two species. In May, alate cotton and cucumber biotypes coexisted on cotton and cucumber seedlings, but each preferred its natal host. Both biotypes existed on zucchini, although the cucumber biotype was more numerous. Aphids on muskmelon were all cucumber biotypes, whereas most aphids on kidney bean were cotton biotypes. Aphids on seedlings of potato and cowpea belong to other species. In August, aphids on cotton and cucumber were the respective biotypes, with zucchini still hosting both biotypes as before. Thus, the biotypes had different fitnesses on different host plants.
Conclusions
Two host-specialized biotypes (cotton and cucumber) are present in North China. Hibiscus, pomegranate, and Chinese prickly ash can serve as winter hosts for the cotton biotype but not the cucumber biotype in North China. The fitnesses of the two host-specialized biotypes differ on various summer hosts. When alate aphids migrate to summer hosts, they cannot accurately land on the corresponding plant. 相似文献
Three new Chinese records, Acaulospora paulinae, Glomus aureum, and Pacispora robigina were found in a survey of arbuscular mycorrhizal fungi associated with Prunus mume in China. They were redescribed and illustrated in accordance with Chinese materials. These specimens were stored in the Herbarium Mycologicum Academiae Sinicae (HMAS) in Beijing. 相似文献