【研究目的】肉鸡骨骼肌的发育情况与肉产量及质量密切相关，而骨骼肌的发育主要依赖于成肌细胞的分化。利钠肽家族成员在哺乳动物骨骼肌的肌管形成及脂肪氧化过程中起重要作用，而C-型利钠肽激素（CNP）作为利钠肽家族的重要成员之一，它对骨骼肌的发育调控作用及机制尚未见相关报道，为更好的理解利钠肽家族在骨骼肌发育中的作用及机制，本研究通过外源10^-7 mol L^-1CNP诱导鸡的原代成肌细胞，探讨CNP对鸡成肌细胞分化的作用及机制。【研究方法】利用CCK8和EDU染色法检测成肌细胞的增殖，Q-PCR技术检测相关基因的表达，转录组测序及生物信息学分析筛选成肌细胞中响应CNP调控的差异基因及显著富集的信号通路。【研究结果】结果表明：与对照组相较，外源添加CNP后，成肌细胞的增殖能力显著增强（P < 0.05）；成肌细胞分化的标志基因MYOD和MYOG表达显著上升（P < 0.05）；CNP的特异性受体NPRB（Natriuretic peptide receptor B） 和清除性受体NPRC（Natriuretic peptide receptor C）的表达显著上调（P < 0.05）；转录组测序分析结果表明，142个差异基因（上调基因84个，下调基因58个）响应CNP对成肌细胞分化的调控作用（P < 0.05）；142个差异表达基因显著富集在8个信号通路（P < 0.05），而代谢通路里富集了16个差异表达基因，其中phospholipase C delta 4（PLCD4）、phospholipase C beta 2（PLCB2）、phosphoglycerate mutase 1（PGAM1）、 creatine kinase B（CKB）、 peroxiredoxin 6（PRDX6）和 CD38这6个基因与骨骼肌的发育密切相关。【研究结论】综上所述，CNP通过上调NPRB/NPRC及富集在代谢通路里的关键基因（PLCD4、 PLCβ2、 PGAM1、 CKB、 PRDX6和 CD38）促进成肌细胞的分化。【创 新 性】本研究利用功能基因验证法和高通量转录组测序法相结合的方法，首次系统阐述了CNP对成肌细胞分化的调控作用及机制，为更好地理解利钠肽家族在骨骼肌发育中的作用及机制奠定了基础。

Twelve fluorescence-labeled microsatellite markers were used to analyze the genetic diversity of 12 domestic duck breeds and 2 wild duck breeds to determine the relationship and origin of Chinese domestic duck breeds. Gene frequency, effective number of alleles (Ne), expected heterozygosity (He), polymorphism information contents (PIC), inbreeding coefficient in population (Fis), standard genetic distance (DS), and genetic distance (DA) were calculated by FSTAT and distance and phylogenetic analysis after the dates which were output from the Microsatellite-Toolkit software. Genetic distances between 12 domestic duck breeds and 2 wild duck breeds were analyzed by variance analysis. Unweighted pair group method with arithmetic mean (UPGMA) and phylogenetic trees used for cluster analysis were structured. The results indicated that 11 loci had medium- or high-level genetic diversity among the 12 loci, which could be efficiently used in the detection of the genetic parameters of each population. The values of He were 0.5414 to 0.7343, those of PIC proved similar, and those of Fis were 0.1101 to 0.3381 among all populations. All breeds were clustered into three groups by UPGMA phylogenetic trees. Banzui duck was clustered into a separate group. Differences of the DA were analysed by t-test. The results showed that difference in DA between the 12 domestic duck breeds and Lvtou duck and the Banzui duck were very significant (P<0.01), indicating that these 12 domestic duck breeds originated from Lvtou wild duck, but not Banzui duck.

The blue gum chalcid, Leptocybe invasa Fisher & La Salle, invaded China in 2007 and has subsequently caused substantial damage to eucalyptus trees. In the current paper, we investigated the susceptibility of 10 Eucalyptus spp. and Eucahetus dunnii to L. invasa in the field, determined the density of galls as well as the gall volume on these tree species, and monitored the population dynamics of wasps in Hainan and Guangdong provinces of China. The order of susceptibility to L. invasa was Eucalyptus urophylla×Eucalyptus camaldulensis>E. urophylla (coppices)>Eucalyptus exserta> Eucalyptus grandis×E. urophylla in Hainan, and Eucalyptus propinqua>Eucalyptus saligna>E. exserta>Eucalyptus microcorys>Eucahetus dunnii>E. camaldulensis>Eucalyptus tereticornis>Eucalyptus robust in Guangdong, China. Although L. invasa generally damages the midribs and petioles of young leaves and the tender bark of twigs of eucalyptus, galls were not observed on leaves of E. microcorys, E. camaldulensis, or E. dunnii. Gall volume significantly differed among the tree species, and gall volume and wasp number were positively correlated. In Dongfang, Hainan Province, the overwintering period of L. invasa emergencing through the year was from the end of December to March of the next year, and the number of population was the greatest on E. urophylla×E. camaldulensis, and the smallest on E. grandis×E. urophylla. In Guangzhou, Guangdong Province, L. invasa hardly emerged in winter from December to June of the next year, and the population was the greatest on E. propinqua, and the smallest on E. microcorys.