cDNA cloning and expression of a potato (Solanum tuberosum) invertase

A cDNA clone encoding an invertase isoenzyme has been isolated from a potato leaf cDNA library. The deduced amino acid sequence shows significant similarities to previously characterised invertases. The highest degree of overall similarity, including the signal peptide sequence, is to carrot cell wall invertase, suggesting that the potato gene encodes an apoplastic enzyme. Expression of the gene, as determined by RT-PCR, is detected in stem and leaf tissue, and at lower levels in tuber, but is absent from roots.     

Molecular characterisation of inter and intra-specific somatic hybrids of potato using randomly amplified polymorphic DNA (RAPD) markers

Summary Protoplast fusion allows the transfer of both mono- and polygenic traits between species that are sexually incompatible. This approach has particular relevance for potato, and somatic hybridisation has been used to introduce a range of disease resistance genes from sexually incompatible wild species into the cultivated potato gene pool. In addition, protoplast fusion allows the resynthesis of tetraploid genotypes from pre-selected diploid or dihaploid donor parents. A limiting factor for the efficient exploitation of this technology in potato breeding is the difficulty of unequivocally identifying nuclear hybrids (heterokaryons). In order to facilitate the identification of hybrids at an early stage following fusion, Randomly Amplified Polymorphic DNA markers (RAPDs) have been used to characterise molecularly both inter- and intra-specific somatic hybrids of potato. RAPD markers detect naturally occurring polymorphism in the donor genotypes and utilise short oligonucleotide primers of arbitrary nucleotide sequence in combination with the polymerase chain reaction (PCR). The exploitation of RAPDs in the characterisation of both somatic and sexual hybrids is discussed.     

Age‐related variation in the trophic characteristics of a marsupial carnivore,the Tasmanian devil Sarcophilus harrisii

Age‐related changes in diet have implications for competitive interactions and for predator–prey dynamics, affecting individuals and groups at different life stages. To quantify patterns of variation and ontogenetic change in the diets of Tasmanian devils Sarcophilus harrisii, a threatened marsupial carnivore, we analyzed variation in the stable isotope composition of whisker tissue samples taken from 91 individual devils from Wilmot, Tasmania from December 2014 to February 2017. Both δ¹³C and δ¹⁵N decreased with increasing age in weaned Tasmanian devils, indicating that as they age devils rely less on small mammals and birds, and more on large herbivores. Devils <12 months old had broader group isotopic niches, as estimated by Bayesian standard ellipses (SEA_B mode = 1.042) than devils from 12 to 23 months old (mode = 0.541) and devils ≥24 months old (mode = 0.532). Devils <24 months old had broader individual isotopic niches (SEA_B mode range 0.492–1.083) than devils ≥24 months old (mode range 0.092–0.240). A decrease in δ¹⁵N from the older whisker sections to the more recently grown sections in devils <24 months old likely reflects the period of weaning in this species, as this pattern was not observed in devils ≥24 months old. Our data reveal changes in the isotopic composition of devil whiskers with increasing age, accompanied by a reduction in isotopic variation both among population age classes and within individuals, reflecting the effect of weaning in early life, and a likely shift from an initially diverse diet of small mammals, birds, and invertebrates towards increasing consumption of larger herbivores in adulthood.     

Time Frame and Justice Motive: Future Perspective Moderates the Adaptive Function of General Belief in a Just World

Background

The human ability to envision the future, that is, to take a future perspective (FP), plays a key role in the justice motive and its function in transcending disadvantages and misfortunes. The present research investigated whether individual (Study 1) and situational (Study 2) differences in FP moderated the association of general belief in a just world (GBJW) with psychological resilience.

Methodology/Principal Findings

We investigated FP, GBJW, and resilience in sample of adolescents (n = 223) and disaster survivors (n = 218) in China. In Study 1, adolescents revealed stronger GBJW than PBJW, and GBJW uniquely predicted resilience in the daily lives of those with high FP (but not those with low FP). In Study 2, natural priming of FP (vs. no FP) facilitated the association of GBJW with resilience after disaster.

Conclusions/Significance

Supporting predictions, participants endorsed GBJW more strongly than PBJW. Further, GBJW interacted with FP in both studies, such that there was an association between GBJW and resilience at high but not low levels of FP. The results corroborate recent findings suggesting that GBJW may be more psychologically adaptive than PBJW among some populations. They also confirm that focusing on the future is an important aspect of the adaptive function of just-world beliefs.     

Demographic buffering and compensatory recruitment promotes the persistence of disease in a wildlife population

Demographic buffering allows populations to persist by compensating for fluctuations in vital rates, including disease‐induced mortality. Using long‐term data on a badger (Meles meles Linnaeus, 1758) population naturally infected with Mycobacterium bovis, we built an integrated population model to quantify impacts of disease, density and environmental drivers on survival and recruitment. Badgers exhibit a slow life‐history strategy, having high rates of adult survival with low variance, and low but variable rates of recruitment. Recruitment exhibited strong negative density‐dependence, but was not influenced by disease, while adult survival was density independent but declined with increasing prevalence of diseased individuals. Given that reproductive success is not depressed by disease prevalence, density‐dependent recruitment of cubs is likely to compensate for disease‐induced mortality. This combination of slow life history and compensatory recruitment promotes the persistence of a naturally infected badger population and helps to explain the badger's role as a persistent reservoir of M. bovis.     

Cylindrospermopsis raciborskii Virus and host: genomic characterization and ecological relevance

Cylindrospermopsis (Raphidiopsis) raciborskii is an invasive, filamentous, nitrogen-fixing cyanobacterium that forms frequent blooms in freshwater habitats. While viruses play key roles in regulating the abundance, production and diversity of their hosts in aquatic ecosystems, the role(s) of viruses in the ecology of C. raciborskii is almost unexplored. Progress in this field has been hindered by the absence of a characterized virus–host system in C. raciborskii. To bridge this gap, we sequenced the genome of CrV-01T, a previously isolated cyanosiphovirus, and its host, C. raciborskii strain Cr2010. Analyses suggest that CrV-01T represents a distinct clade of siphoviruses infecting, and perhaps lysogenizing, filamentous cyanobacteria. Its genome contains unique features that include an intact CRISPR array and a 12 kb inverted duplication. Evidence suggests CrV-01T recently gained the ability to infect Cr2010 and recently lost the ability to form lysogens. The cyanobacterial host contains a CRISPR-Cas system with CRISPR spacers matching protospacers within the inverted duplication of the CrV-01T genome. Examination of metagenomes demonstrates that viruses with high genetic identity to CrV-01T, but lacking the inverted duplication, are present in C. raciborskii blooms in Australia. The unique genomic features of the CrV/Cr2010 system offers opportunities to investigate in more detail virus–host interactions in an ecologically important bloom-forming cyanobacterium.