Genome-wide association mapping of sexual incompatibility genes in cacao (<Emphasis Type="Italic">Theobroma cacao</Emphasis> L.)

Sexual compatibility limits the production of cacao plantations, being an important selection criterion in breeding programs. However, the current method for characterizing compatibility, based on the frequency of flower setting after controlled pollination, is time consuming, requiring a long time to identify self-compatible individuals. The identification of molecular markers in genomic regions can be an alternative to allow early selection of self-compatible plants. The present study aimed to identify SNP markers associated with sexual compatibility in cacao, by utilizing genome-wide association (GWAS) mapping. A population of 295 individuals mostly from third-generation breeding populations, but also founder clones, was used. This population was phenotypically characterized by hand pollinating 8199 flowers and evaluating the flower retention 15 days after pollination. In addition, leaf samples of each individual were collected and DNA extracted for genotyping by sequencing, generating 5301 SNP markers after cleaning. Genome-wide association mapping analysis was performed using Synbreed, GCTA, and TASSEL softwares. Significant markers associated to incompatibility, likely in strong linkage disequilibrium, were found within a region of 196 kb, in the proximal end of chromosome 4, suggesting the existence of a major gene in that region. However, this result should be validated in a larger population, considering that only 295 trees were used here. When the SNP effects were treated as random in the estimation process, many other regions in the genome appears to be involved with sexual incompatibility in cacao. Candidate genes were found not only in the proximal end of chromosome 4 but also spread in several other regions of the genome.     

Development of a Teat Bio-sealant and Evaluation of its Technological and Functional Properties

A teat bio-sealant was developed using Weissella cibaria, and the bio-sealant’s technological and functional properties were assessed. The development included four experimental phases that were analyzed using independent experimental designs. Initially, sterilized or pasteurized Aloe vera gels were used, and the effect of heat treatment was investigated. In the second phase, the effects of time, storage temperature, and addition of cryopreservatives on the viability of the probiotic were observed. The third phase consisted of evaluating the synergistic effects of the cryopreservatives. The fourth phase involved selecting a material that would provide viscosity to the teat sealant. Technological and functional properties were measured in terms of viability of W. cibaria, and antimicrobial activity against Staphylococcus aureus and Streptococcus agalactiae was also analyzed. A mixture of milk powder and glycerol preserved this antimicrobial activity. Pullulan provided greater viscosity and maintained the technological and functional properties of the bio-sealant for 29 days. This teat bio-sealant can be used as an alternative for the prevention of bovine mastitis.     

Transgenic mice recapitulate the phenotypic heterogeneity of genetic prion diseases without developing prion infectivity: Role of intracellular PrP retention in neurotoxicity

Genetic prion diseases are degenerative brain disorders caused by mutations in the gene encoding the prion protein (PrP). Different PrP mutations cause different diseases, including Creutzfeldt-Jakob disease (CJD), Gerstmann-Sträussler-Scheinker (GSS) syndrome and fatal familial insomnia (FFI). The reason for this variability is not known. It has been suggested that prion strains with unique self-replicating and neurotoxic properties emerge spontaneously in individuals carrying PrP mutations, dictating the phenotypic expression of disease. We generated transgenic mice expressing the FFI mutation, and found that they developed a fatal neurological illness highly reminiscent of FFI, and different from those of similarly generated mice modeling genetic CJD and GSS. Thus transgenic mice recapitulate the phenotypic differences seen in humans. The mutant PrPs expressed in these mice are misfolded but unable to self-replicate. They accumulate in different compartments of the neuronal secretory pathway, impairing the membrane delivery of ion channels essential for neuronal function. Our results indicate that conversion of mutant PrP into an infectious isoform is not required for pathogenesis, and suggest that the phenotypic variability may be due to different effects of mutant PrP on intracellular transport.     

Novel materials based on DNA‐CTMA and lanthanide (Ce3+, Pr3+)

New, deoxyribonucleic acid (DNA) based compounds, functionalized with hexadecyltrimethylammonium chloride (CTMA) and lanthanide hydroxide nanoparticles were synthesized. The spectral measurements suggest that between the DNA‐CTMA complex and the lanthanide (III) ions a chemical interaction takes place. The obtained materials exhibit an improved fluorescence efficiency, showing a potential interest for application in photonics, and more particularly, in light emitting devices. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 613–617, 2016.     

A constitutive expression system for <Emphasis Type="Italic">Pichia pastoris</Emphasis> based on the <Emphasis Type="Italic">PGK1</Emphasis> promoter

Objectives

To develop a new vector for constitutive expression in Pichia pastoris based on the endogenous glycolytic PGK1 promoter.

Results

P. pastoris plasmids bearing at least 415 bp of PGK1 promoter sequences can be used to drive plasmid integration by addition at this locus without affecting cell growth. Based on this result, a new P. pastoris integrative vector, pPICK2, was constructed bearing some features that facilitate protein production in this yeast: a ~620 bp PGK1 promoter fragment with three options of restriction sites for plasmid linearization prior to yeast transformation: a codon-optimized α-factor secretion signal, a new polylinker, and the kan marker for vector propagation in bacteria and selection of yeast transformants.

Conclusions

A new constitutive vector for P. pastoris represents an alternative platform for recombinant protein production and metabolic engineering purposes.

     

“Thinking a Lot” Among the Khwe of South Africa: A Key Idiom of Personal and Interpersonal Distress

“Thinking too much”, and variations such as “thinking a lot”, are common idioms of distress across the world. The contextual meaning of this idiom of distress in particular localities remains largely unknown. This paper reports on a systematic study of the content and cause, consequences, and social response and coping related to the local terms |x’an n|a te and |eu-ca n|a te, both translated as “thinking a lot”, and was part of a larger ethnographic study among the Khwe of South Africa. Semi-structured exploratory interviews with community members revealed that “thinking a lot” refers to a common experience of reflecting on personal and interpersonal problems. Consequences were described in emotional, psychological, social, behavioral, and physical effects. Coping strategies included social support, distraction, and religious practices. Our contextualized approach revealed meanings and experiences of “thinking a lot” that go beyond a psychological state or psychopathology. The common experience of “thinking a lot” is situated in socio-political, economic, and social context that reflect the marginalized and displaced position of the Khwe. We argue that “thinking a lot” and associated local meanings may vary across settings, may not necessarily indicate psychopathology, and should be understood in individual, interpersonal, community, and socio-political dimensions.     

Omgaan met somberheid op oudere leeftijd: een kwalitatieve studie

Background

To gain new insights for support for older people with low mood, we explored the perceptions of ‘screenpositive’ older people on underlying causes and possible solutions.

Design and method

We conducted two in-depth interviews with 38 participants (≥77 years) who screened positive for depressive symptoms in general practice. To investigate the influence of the presence of complex health problems, we included 19 persons with and 19 without complex problems. Complex problems were defined as a combination of functional, somatic, psychological or social problems.

Results

All participants used several cognitive, social or practical coping strategies. Four patterns emerged: mastery, acceptance, ambivalence, and need for support. Some participants, especially those with complex problems, were ambivalent about possible interventions.

Conclusion

Most older participants perceived their coping strategies as sufficient. General practitioners can support self-management by exploring the (effectiveness of) personal coping strategies, providing information, elaborating on perceptions of risks and discussing alternative options with older persons.