《免疫学基础与病原生物学》移动交互式数字教材在“抗疫”时期在线教学中的应用

新型冠状病毒肺炎疫情暴发以来,全国各级各类学校延期开学,但停课不停教、停课不停学。各学校教师利用各种网络资源开展在线教学,也为深入挖掘"互联网+教育"教学新模式带来了契机。本文以《免疫学基础与病原生物学》移动交互式数字教材(云教材)应用为例,介绍如何应用移动交互式数字教材创设合理的学习情境,从而实现交互式学习,提升线上学习教学效果。     

乙脑/登革2型嵌合病毒的构建

在乙脑病毒SA14-14-2株复制子载体pPartial△prM/E中克隆入DV2(Dengue virus serotype 2)的prM/E基因,构建乙脑/登革2型嵌合体克隆。将嵌合体克隆线性化后体外转录,获得的RNA转染BHK-21细胞,5～7d可观察到CPE。收获病毒上清液分别感染BHK-21细胞及C6/36细胞。接种于C6/36细胞中的嵌合病毒可使细胞出现CPE,RT-PCR、间接免疫荧光和Western blot检测显示:获得的嵌合病毒具有预期嵌合性核酸并能表达DV2的包膜蛋白,但不能在BHK-21细胞中传代培养。成功构建的乙脑/登革2型感染性克隆为进一步研究登革病毒疫苗奠定了基础。     

Evolution of sexual size dimorphism in grouse and allies (Aves: Phasianidae) in relation to mating competition,fecundity demands and resource division

Sexual size dimorphism (SSD) is often assumed to be driven by three major selective processes: (1) sexual selection influencing male size and thus mating success, (2) fecundity selection acting on females and (3) inter‐sexual resource division favouring different size in males and females to reduce competition for resources. Sexual selection should be particularly strong in species that exhibit lek polygyny, since male mating success is highly skewed in such species. We investigated whether these three selective processes are related to SSD evolution in grouse and allies (Phasianidae). Male‐biased SSD increased with body size (Rensch’s rule) and lekking species exhibited more male‐biased SSD than nonlekking ones. Directional phylogenetic analyses indicated that lekking evolved before SSD, but conclusions were highly dependent on the body size traits and chosen model values. There was no relationship between SSD and male display agility, nor did resource division influence SSD. Although clutch mass increased with female body size it was not related to the degree of SSD. Taken together, the results are most consistent with the hypothesis that lekking behaviour led to the evolution of male‐biased SSD in Phasianidae.     

Rapid evolution of social learning

Culture is widely thought to be beneficial when social learning is less costly than individual learning and thus may explain the enormous ecological success of humans. Rogers (1988. Does biology constrain culture. Am. Anthropol.  90 : 819–831) contradicted this common view by showing that the evolution of social learning does not necessarily increase the net benefits of learned behaviours in a variable environment. Using simulation experiments, we re‐analysed extensions of Rogers’ model after relaxing the assumption that genetic evolution is much slower than cultural evolution. Our results show that this assumption is crucial for Rogers’ finding. For many parameter settings, genetic and cultural evolution occur on the same time scale, and feedback effects between genetic and cultural dynamics increase the net benefits. Thus, by avoiding the costs of individual learning, social learning can increase ecological success. Furthermore, we found that rapid evolution can limit the evolution of complex social learning strategies, which have been proposed to be widespread in animals.     

Routes to indirect fitness in cooperatively breeding vertebrates: kin discrimination and limited dispersal

Hamilton demonstrated that the evolution of cooperative behaviour is favoured by high relatedness, which can arise through kin discrimination or limited dispersal (population viscosity). These two processes are likely to operate with limited overlap: kin discrimination is beneficial when variation in relatedness is higher, whereas limited dispersal results in less variable and higher average relatedness, reducing selection for kin discrimination. However, most empirical work on eukaryotes has focused on kin discrimination. To address this bias, we analysed how kin discrimination and limited dispersal interact to shape helping behaviour across cooperatively breeding vertebrates. We show that kin discrimination is greater in species where the: (i) average relatedness in groups is lower and more variable; (ii) effect of helpers on breeders reproductive success is greater; and (iii) probability of helping was measured, rather than the amount of help provided. There was also an interaction between these effects with the correlation between the benefits of helping and kin discrimination being stronger in species with higher variance in relatedness. Overall, our results suggest that kin discrimination provides a route to indirect benefits when relatedness is too variable within groups to favour indiscriminate cooperation.     

Long-term stability studies on protection against Newcastle disease by commercial live vaccine used in Brazil

The thermostability (TS) and efficacy offered by live vaccines against Newcastle disease strains B1, La Sota, VG-GA and Ulster, produced or imported by four Brazilian laboratories, were evaluated during their validity period. Kinetic profiles were obtained from samples conserved in refrigerators during 0, 4, 8, 12, 16, 20 and 24 months after their manufacturing. The statistical analysis of the vaccine titre effect obtained by the fresh air (FA) method showed that the vaccine profiles were parallel and coincident, presenting a significant descending trend. The vaccine titres and efficiency proofs at the end of the validity period were above the level of legislation requirements and showed an average loss in titre of 0.40 and 0.66 log_10, within the first and second validity years, respectively. The titre obtained by TS, within the month after manufacturing, had no significant difference from the titre obtained by FA within 24 months after manufacturing, being their pairs of observations positively correlated (r = 0.49, p = 0.0003), showing that the TS method, which anticipates the vaccines' performance at the end of the validity period, can substitute the FA method 24 months after manufacturing.     

Generation of transgenic monkeys with human inherited genetic disease

Modeling human diseases using nonhuman primates including chimpanzee, rhesus, cynomolgus, marmoset and squirrel monkeys has been reported in the past decades. Due to the high similarity between nonhuman primates and humans, including genome constitution, cognitive behavioral functions, anatomical structure, metabolic, reproductive, and brain functions; nonhuman primates have played an important role in understanding physiological functions of the human body, clarifying the underlying mechanism of human diseases, and the development of novel treatments for human diseases. However, nonhuman primate research has been restricted to cognitive, behavioral, biochemical and pharmacological approaches of human diseases due to the limitation of gene transfer technology in nonhuman primates. The recent advancement in transgenic technology that has led to the generation of the first transgenic monkey in 2001 and a transgenic monkey model of Huntington’s disease (HD) in 2008 has changed that focus. The creation of transgenic HD monkeys that replicate key pathological features of human HD patients further suggests the crucial role of nonhuman primates in the future development of biomedicine. These successes have opened the door to genetic manipulation in nonhuman primates and a new era in modeling human inherited genetic disorders. We focused on the procedures in creating transgenic Huntington’s disease monkeys, but our work can be applied to transgenesis in other nonhuman primate species.     

Consensus-degenerate hybrid oligonucleotide primers (CODEHOPs) for the detection of novel viruses in non-human primates

Consensus-degenerate hybrid oligonucleotide primers (CODEHOPs) have proven to be a powerful tool for the identification of novel genes. CODEHOPs are designed from highly-conserved regions of multiply-aligned protein sequences from members of a gene family and are used in PCR amplification to identify distantly-related genes. The CODEHOP approach has been used to identify novel pathogens by targeting amino acid motifs conserved in specific pathogen families. We initiated a program utilizing the CODEHOP approach to develop PCR-based assays targeting a variety of viral families that are pathogens in non-human primates. We have also developed and further improved a computer program and website to facilitate the design of CODEHOP PCR primers. Here, we detail the method for the development of pathogen-specific CODEHOP PCR assays using the papillomavirus family as a target. Papillomaviruses constitute a diverse virus family infecting a wide variety of mammalian species, including humans and non-human primates. We demonstrate that our pan-papillomavirus CODEHOP assay is broadly reactive with all major branches of the virus family and show its utility in identifying a novel non-human primate papillomavirus in cynomolgus macaques.     

Best linear unbiased prediction of host-range of the facultative parasite Colletotrichum gloeosporioides f. sp. salsolae, a potential biological control agent of Russian thistle

Russian thistle or tumbleweed (Salsola tragus L.) is an introduced invasive weed in N. America. It is widely distributed in the US and is a target of biological control efforts.The fungus Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. in Penz. f. sp. salsolae (CGS) is a facultative parasite under evaluation for classical biological control of this weed. Host-range tests were conducted with CGS in quarantine to determine whether the fungus is safe to release in N. America. Ninetytwo accessions were analyzed from 19 families: Aizoaceae, Alliaceae, Amaranthaceae, Apiaceae, Asteraceae, Brassicaceae, Cactaceae, Campanulaceae, Chenopodiaceae, Cucurbitaceae, Cupressaceae, Fabaceae, Malvaceae, Nyctaginaceae, Phytolaccaceae, Poaceae, Polygonaceae, Sarcobataceae, and Solanaceae and 10 tribes within the Chenopodiaceae: Atripliceae, Beteae, Camphorosmeae, Chenopodieae, Corispermeae, Halopepideae, Polycnemeae, Salicornieae, Salsoleae, and Suaedeae. These included 62 genera and 120 species. To facilitate interpretation of results, disease reaction data were combined with a relationship matrix derived from internal transcribed spacer DNA sequences and analyzed with mixed model equations to produce Best Linear Unbiased Predictors (BLUPs) for each species. Twenty-nine species (30 accessions) from seven closely-related Chenopodiaceae tribes had significant levels of disease severity as indicated by BLUPs, compared to six species determined to be susceptible with least squares means estimates. The 29 susceptible species were: 1 from Atripliceae, 4 from Camphorosmeae, 1 from Halopepideae, 2 from Polycnemeae, 6 from Salicornieae, 8 from Salsolae, and 7 from Suaedeae. Most species in the genus Salsola, which are all introduced and weedy, were very susceptible and damaged by CGS. Statistical comparisons and contrasts of BLUPs indicated that these Salsola species were significantly more susceptible than non-target species, including 15 species from relatives in the closely-related genera Bassia (=Kochia), Nitrophila, Salicornia, Sarcocornia, and Suaeda. Of the 29 susceptible species, 10 native or commercially important species in N. America were identified as needing additional tests to determine the extent of any damage caused by infection.