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The fall armyworm (Spodoptera frugiperda), a destructive pest that originated in South and North America, spread to China in early 2019. Controlling this invasive pest requires an understanding of its population structure and migration patterns, yet the invasion genetics of Chinese S. frugiperda is not clear. Here, using the mitochondrial cytochrome oxidase subunit I (COI) gene, triose phosphate isomerase (Tpi) gene and eight microsatellite loci, we investigated genetic structure and genetic diversity of 16 S. frugiperda populations in China. The Tpi locus identified most S. frugiperda populations as the corn-strains, and a few were heterozygous strains. The microsatellite loci revealed that the genetic diversity of this pest in China was lower than that in South America. Furthermore, we found moderate differentiation among the populations, distinct genetic structures between adjacent populations and abundant genetic resources in the S. frugiperda populations from China sampled across 2 years. The survival rate of S. frugiperda was significantly higher when it was fed on corn leaves than on rice leaves, and the larval stage mortality rate was the highest under both treatments. Our results showed that S. frugiperda probably invaded China via multiple independent introductions and careful pesticide control, continuous monitoring and further studies will be needed to minimize its potential future outbreak.
The Wulanba granite, consisting of biotite monzogranite and syenogranite, is located in the southern part of the Great Xing’an Range, NE China. Whole-rock major- and trace-element geochemistry suggests the Wulanba granite is a high-K–shoshonitic, slightly peraluminous and highly differentiated I-type granite. The Sr–Nd–Hf isotopes indicate that it originated from partial melting of juvenile crust derived from the depleted mantle with a minor input of old crust. The relatively young T2DM and tDM2 ages indicate it was most likely derived from a Late Neoproterozoic to Early Palaeozoic source. We have demonstrated that the biotite monzogranite is the ore-related intrusion of the Haobugao Zn–Fe mineralization based on the following geological, geochronological and geochemical evidence: (1) the chalcopyrite/pyrite in the biotite monzogranite and the continuous mineralization of drill core ZK2508; (2) the consistence of the emplacement age of the biotite monzogranite (~141–140/138 Ma) with the skarn mineralization age (~142 Ma); and (3) the presence of rich ore-forming elements (Fe–Zn–Cu) in the biotite monzogranite, and the similar Pb compositions of the sulfides from the Haobugao deposit and the biotite monzogranite. Compared to the barren syenogranite, the fertile biotite monzogranite is more oxidized, while the edges of the apatite grains in the biotite monzogranite are more oxidized than the centres. The average F/Cl ratio of the fertile biotite monzogranite (~123.45) is much higher than that of the barren syenogranite (~73.98). We conclude that these differences reflect unique geochemical signatures, and the geochemical composition of the apatite can be used to infer the economic potential of granites.
Northeastern China is a region of high tick abundance, multiple tick-borne pathogens and likely human infections. The spectrum of diseases caused by tick-borne pathogens has not been objectively evaluated in this region for clinical management and for comparison with other regions globally where tick-transmitted diseases are common. Based on clinical symptoms, PCR, indirect immunofluorescent assay and (or) blood smear, we identified and described tick-borne diseases from patients with recent tick bite seen at Mudanjiang Forestry Central Hospital. From May 2010 to September 2011, 42% (75/180) of patients were diagnosed with a specific tick-borne disease, including Lyme borreliosis, tick-borne encephalitis, human granulocytic anaplasmosis, human babesiosis and spotted fever group rickettsiosis. When we compared clinical and laboratory features to identify factors that might discriminate tick-transmitted infections from those lacking that evidence, we revealed that erythema migrans and neurological manifestations were statistically significantly differently presented between those with and without documented aetiologies (P < 0.001, P = 0.003). Twelve patients (6.7%, 12/180) were co-infected with two tick-borne pathogens. We demonstrated the poor ability of clinicians to identify the specific tick-borne disease. In addition, it is necessary to develop specific laboratory assays for optimal diagnosis of tick-borne diseases.
Boulders are ubiquitous on the surfaces of asteroids and their spatial and size distributions provide information for the geological evolution and collisional history of parent bodies. We identify more than 200 boulders on near-Earth asteroid 4179 Toutatis based on images obtained by Chang'e-2 flyby. The cumulative boulder size frequency distribution (SFD) gives a power-index of −4.4 ± 0.1, which is clearly steeper than those of boulders on Itokawa and Eros, indicating much high degree of fragmentation. Correlation analyses with craters suggest that most boulders cannot solely be produced as products of cratering, but are probably survived fragments from the parent body of Toutatis, accreted after its breakup. Similar to Itokawa, Toutatis probably has a rubble-pile structure, but owns a different preservation state of boulders.
Melanocortin-4 receptor (MC4R) is a member of the superfamily of G-protein-coupled receptors (GPCRs), which affects body weight, energy homeostasis and food intake in humans and mice. In this study, the Asp298Asn polymorphism of the MC4R gene was investigated in Laiwu, Yorkshire×Laiwu and commercial cross-bred pig populations using polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP), and the relationship of this mutation with backfat thickness was analysed. The results indicated that only genotype 11 exists in 33 individuals of Laiwu pigs, and three genotypes (11, 12 and 22) were detected in Yorkshire×Laiwu and commercial cross-bred populations. The distributions of allele and genotype frequencies in Yorkshire×Laiwu and commercial cross-bred populations were similar, with the frequency of allele 1 being higher than that of allele 2. In commercial cross-bred pigs, the mean backfat thickness of individuals with genotype 22 was significantly higher than that of individuals with genotypes 12 (P<0.01) and 11 (P<0.05). This study provides evidence that the Asp298Asn polymorphism of the MC4R gene is associated with backfat thickness in commercial cross-bred pigs with Western pigs as parental lines and, therefore, can be used as a DNA marker for breeding in such populations of pigs.
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