Identifying a Carotenoid Cleavage Dioxygenase (ccd4) Gene Controlling Yellow/White Fruit Flesh Color of Peach

Peach flesh color is a monogenic trait with the white phenotype being dominant over the yellow; its expression has been reported to be determined by a carotenoid degradative enzyme. In the present study, a carotenoid cleavage dioxygenase (ccd4) gene was analyzed to test whether it can be responsible for the flesh color determinism. The analysis was conducted on chimeric mutants with white and yellow sectors of the fruit mesocarp; it was then extended to a pool of cultivars and a segregating F₁ population. A ccd4 functional allele is consistently associated with the ancestral white flesh color; on the other hand, the yellow phenotype originated from at least three independent mutations disrupting ccd4 function, thus preventing carotenoid degradation. In addition, retro-mutations recovering ccd4 function and re-establishing the ancestral white flesh color were detected. Our results show that ccd4 is the gene controlling flesh color in peach; its expression results in the degradation of carotenoids in white-fleshed genotypes, while the yellow color arises as a consequence of its inactivation.     

Mutations in the CCD4 Carotenoid Cleavage Dioxygenase Gene of Yellow-Flesh Peaches

Peach trees bear either white- or yellow-flesh fruit. We found that Japanese peach cultivars have two types of mutation in a carotenoid catabolic gene, CCD4: the insertion of a retrotransposon, and a frame shift in the microsatellite sequences of the first exon. CCD4 in yellow-flesh peaches was disrupted by these mutations.     

Silencing of the Host Factor eIF(iso)4E Gene Confers Plum Pox Virus Resistance in Plum

Plum pox virus (PPV) causes the most economically-devastating viral disease in Prunus species. Unfortunately, few natural resistance genes are available for the control of PPV. Recessive resistance to some potyviruses is associated with mutations of eukaryotic translation initiation factor 4E (eIF4E) or its isoform eIF(iso)4E. In this study, we used an RNA silencing approach to manipulate the expression of eIF4E and eIF(iso)4E towards the development of PPV resistance in Prunus species. The eIF4E and eIF(iso)4E genes were cloned from plum (Prunus domestica L.). The sequence identity between plum eIF4E and eIF(iso)4E coding sequences is 60.4% at the nucleotide level and 52.1% at the amino acid level. Quantitative real-time RT-PCR analysis showed that these two genes have a similar expression pattern in different tissues. Transgenes allowing the production of hairpin RNAs of plum eIF4E or eIF(iso)4E were introduced into plum via Agrobacterium-mediated transformation. Gene expression analysis confirmed specific reduced expression of eIF4E or eIF(iso)4E in the transgenic lines and this was associated with the accumulation of siRNAs. Transgenic plants were challenged with PPV-D strain and resistance was evaluated by measuring the concentration of viral RNA. Eighty-two percent of the eIF(iso)4E silenced transgenic plants were resistant to PPV, while eIF4E silenced transgenic plants did not show PPV resistance. Physical interaction between PPV-VPg and plum eIF(iso)4E was confirmed. In contrast, no PPV-VPg/eIF4E interaction was observed. These results indicate that eIF(iso)4E is involved in PPV infection in plum, and that silencing of eIF(iso)4E expression can lead to PPV resistance in Prunus species.     

Sex Pheromone Composition and Male Trapping of the Peach Fruit Moth,Carposina sasakii (Matsumura) (Lepidoptera: Carposinidae) in Korea

Sex pheromone composition, mating behavior, and field trapping were analyzed for the peach fruit moth, Carposina sasakii(Matsumura) to develop a monitoring system with its sex pheromone. The upwind flying response of males to female was the most frequent at 4th to 5th hr after lights-off. The highest mating rate was seen at 5th hr after lights-off. The extract of female abdominal tip was analyzed with gas chromatography and proved to have two compounds, (Z)-7-eicosen-11-one and (Z)-7-nonadecen-11-one. In field-trapping, however, a lure containing (Z)-7-eicosen-11-one only showed the highest attractivity.     

桃ERF转录因子家族生物信息学分析及 芽萌发相关基因筛选

以中油四号油桃(Prunus persica var. nectarina)为研究对象, 利用MEGA 6.0、MEME、GSDS和DNAMAN 6.0等软件对桃ERF家族数据进行生物信息学分析, 鉴定得到102个ERF转录因子家族基因, 并通过构建系统进化树将这102个基因分为10个子家族(I-X)。基因结构分析表明, 有81个基因不含内含子, 20个基因含有1个内含子, 有1个基因与其它成员差异较大, 含有5个内含子。保守元件分析表明, ERF家族包含20个保守元件, 其中Motif 1、Motif 2和Motif 4都属于AP2/ERF结构域, 同一个保守元件主要出现在同一个子家族中, 并且大部分保守元件的功能未知。VIII子家族基因的荧光定量PCR分析表明, 在桃叶芽处于不同的发育状态时, PpeERF068的表达量存在较大差异, 光照培养箱中培养的桃芽在萌发过程中各时期表达量变化趋势进一步表明该基因可能与叶芽萌发有关, 将其命名为PpeEBB1。该研究为进一步揭示PpeEBB1的分子机制奠定了基础, 并为桃树的栽培管理和熟期调控了提供理论指导。     

Genetic Diversity of the Melanocortin 4 Receptor (MC4R) Gene and its Association with Slaughter Traits in the Landes Goose

Melanocortin 4 receptor (MC4R) plays a crucial part in regulating feeding behavior in humans and rodents. We detected two single nucleotide polymorphisms (SNPs; c.108G → A and c.627C → T) in the goose MC4R gene and genotyped 94 Landes geese for association analysis with several carcass traits. Significant associations (P < 0.05) were obtained for c.108G → A with carcass weight, breast muscle percentage, and leg muscle percentage, and for c.627C → T with body weight, carcass weight, semi-eviscerated weight, and eviscerated weight. We re-constructed haplotypes based on the two SNPs and analyzed diplotypes in association with carcass traits, obtaining significant associations with several of the traits. These results suggest that polymorphisms in the MC4R gene could have effects on carcass traits in Landes geese. More study is required to confirm these results.     

Convergence and Divergence in Direct and Indirect Life-History Traits of Closely Related Parasitoids (Braconidae: Microgastrinae)

Closely related species in nature often show similarities in suites of direct and indirect traits that reveal aspects of their phylogenetic history. Here we tested how common descent affects trait evolution in several closely related parasitoid species in the genera Cotesia and Microplitis (Hymenoptera: Braconidae: Microgastrinae) by comparing development, resource use and allocation into reproduction and maintenance. Parasitoids in these genera exhibit traits, like haemolymph feeding as larvae and external pupation that are rare in most parasitoid lineages. The growth of parasitized hosts was reduced by 90 % compared with healthy hosts, and maximum host size depended to a large extent on adult parasitoid size. Development time was longer in the more generalist parasitoids than in the specialists. Adult body mass was sexually dimorphic in all Cotesia species, with females being larger, but not in Microplitis spp. In contrast, in one of the Microplitis species males were found to be the larger sex. Egg load dynamics during the first 6 days after emergence were highly variable but egg number was typically higher in Cotesia spp. compared to Microplitis spp. Longevity in the various species was only greater in female than in male wasps in two Microplitis sp. There was a clear inverse relationship between resource use and allocation, e.g. maximum egg load and longevity, in these parasitoids. Our results reveal that adaptation to constraints imposed by host quality and availability has resulted in trait convergence and divergence at the species, genus and subfamily level.     

Olfactory Learning of Fruit Odors in the Eastern Yellow Jacket, Vespula maculifrons (Hymenoptera: Vespidae)

Food-seaching workers of eastern yellow jackets, Vespula maculifrons, are attracted by the natural odors of a wide variety of succulent fruits; particularly effective was pear. The only part of a fruit that repelled was the leathery epicarp of oranges. After rewarding with sugar water, odors of six fruits, including the pulpy mesocarp of oranges and, in addition, the leaves of catmint Nepeta cataria, all become highly attractive. To learn the distinctive odors of any one of three fruits (pear, apple, quince), nondiscrimination training with a rewarded fruit was sufficient for the subsequent olfactory preference of the training fruit over the control fruit. In the other cases [banana, hawthorn (Crataegus crus-galli), grape] simultaneous discrimination training with a rewarded and an unrewarded fruit was necessary and effective for obtaining differential responses to the odors of the training fruits. As far as current evidence goes, olfactory learning plays similar roles in the fruit foraging of this wasp and in the nectar foraging of the honey bee (Apis mellifera).     

Overexpression of a Rice Monosaccharide Transporter Gene (OsMST6) Confers Enhanced Tolerance to Drought and Salinity Stress in Arabidopsis thaliana

Plant Molecular Biology Reporter - Monosaccharide transporter (MSTs) is a large family of integral membrane proteins that plays a crucial role in cell-to-cell and long-distance distribution of...     

陆海BC_4F_3和BC_4F_(3:4)代换系纤维产量与品质的表型评价

对陆海BC4F3和BC4F3:4代换系群体的纤维产量与品质的表型性状进行初步评价分析,结果表明,群体代换系各性状平均值与轮回亲本中棉所45相近,但群体内部个体间仍存在丰富的遗传变异,其中不乏超越中棉所45的材料。从中筛选20个纤维品质突出单株(株行),2年的上半部平均长度高于30.00 mm,断裂比强度高于31.0 c N/tex,表现较好的一致性和稳定性,为进一步棉花纤维品质育种提供了选择材料。     

Nucleoredoxin Negatively Regulates Toll-like Receptor 4 Signaling via Recruitment of Flightless-I to Myeloid Differentiation Primary Response Gene (88)

We previously characterized nucleoredoxin (NRX) as a negative regulator of the Wnt signaling pathway through Dishevelled (Dvl). We perform a comprehensive search for other NRX-interacting proteins and identify Flightless-I (Fli-I) as a novel NRX-binding partner. Fli-I binds to NRX and other related proteins, such as Rod-derived cone viability factor (RdCVF), whereas Dvl binds only to NRX. Endogenous NRX and Fli-I in vivo interactions are confirmed. Both NRX and RdCVF link Fli-I with myeloid differentiation primary response gene (88) (MyD88), an important adaptor protein for innate immune response. NRX and RdCVF also potentiate the negative effect of Fli-I upon lipopolysaccharide-induced activation of NF-κB through the Toll-like receptor 4/MyD88 pathway. Embryonic fibroblasts derived from NRX gene-targeted mice show aberrant NF-κB activation upon lipopolysaccharide stimulation. These results suggest that the NRX subfamily of proteins forms a link between MyD88 and Fli-I to mediate negative regulation of the Toll-like receptor 4/MyD88 pathway.     

Adaptive Evolution of the Myo6 Gene in Old World Fruit Bats (Family: Pteropodidae)

Myosin VI (encoded by the Myo6 gene) is highly expressed in the inner and outer hair cells of the ear, retina, and polarized epithelial cells such as kidney proximal tubule cells and intestinal enterocytes. The Myo6 gene is thought to be involved in a wide range of physiological functions such as hearing, vision, and clathrin-mediated endocytosis. Bats (Chiroptera) represent one of the most fascinating mammal groups for molecular evolutionary studies of the Myo6 gene. A diversity of specialized adaptations occur among different bat lineages, such as echolocation and associated high-frequency hearing in laryngeal echolocating bats, large eyes and a strong dependence on vision in Old World fruit bats (Pteropodidae), and specialized high-carbohydrate but low-nitrogen diets in both Old World and New World fruit bats (Phyllostomidae). To investigate what role(s) the Myo6 gene might fulfill in bats, we sequenced the coding region of the Myo6 gene in 15 bat species and used molecular evolutionary analyses to detect evidence of positive selection in different bat lineages. We also conducted real-time PCR assays to explore the expression levels of Myo6 in a range of tissues from three representative bat species. Molecular evolutionary analyses revealed that the Myo6 gene, which was widely considered as a hearing gene, has undergone adaptive evolution in the Old World fruit bats which lack laryngeal echolocation and associated high-frequency hearing. Real-time PCR showed the highest expression level of the Myo6 gene in the kidney among ten tissues examined in three bat species, indicating an important role for this gene in kidney function. We suggest that Myo6 has undergone adaptive evolution in Old World fruit bats in relation to receptor-mediated endocytosis for the preservation of protein and essential nutrients.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases