BMC Series blog Highlights of the BMC-series: May 2013

Antibiotic avoidance • Conversion of Coccidioides • The geography of mutation • A structural mystery, resolved • Snowflake the albino gorilla • A hidden mechanism of signalling? • Evolution and medicine across Africa • Is it right to recruit by genotype?

Healthcare: Antibiotic avoidance

Over a third of women presenting with urinary tract infection symptoms are happy to delay antibiotic treatment when asked by their GP, with the majority of these patients showing an improvement in symptoms without the need for further treatment. This intriguingly suggests that patients are much more open to reducing unnecessary antibiotic use than is often thought. More on this study over on our blog.

Microbiology: Conversion of Coccidioides

Coccidioides immitis is a disease-causing fungus in mammals that exists as molds in the wild, growing in the desert soils of the southwestern US, and in Central and South America. In humans it can cause Valley Fever or pneumonia through inhalation of spores which eventually turn into pathogenic spherules. Viriyakosol et al. now report that this conversion from spores to spherules requires major transcriptional reprogramming, and has little congruence with genetic mechanisms displayed in other dimorphic fungi.

Cancer: The geography of mutation

A study of the prevalence of genetic mutations in the breast- and ovarian-cancer related genes BRCA1 and BRCA2 in the northern Spanish region of Asturias reveals a number of novel mutations not found in other regions of the country, which may help design a geography-specific screening panel for high-risk breast and/or ovarian cancer families.

Biochemistry: A structural mystery, resolved

Bacterial replicative DNA polymerases contain a Polymerase and Histidinol Phosphatase (PHP) domain that plays a role in proofreading newly synthesized DNA. However, in E. coli DNA polymerase III the metal-binding residues that underlie this function have been lost, and so the function of this domain is not clear. A new analysis from the Kuriyan lab in UC Berkeley finds that metal binding can be restored with only three point mutations, and that the domain is in fact a major structural element.

Image of the month:

The genome sequencing of Snowflake, the only known albino gorilla, reveals traces of inbreeding. Prado-Martinez et al.

Plant biology: A hidden mechanism of signalling?

Chilli seedlings germinate better when grown in the presence of ‘good neighbour’ plants like basil even when all forms of chemical and visual signals are blocked, suggesting that an as-yet unidentified system of communication exists between plants. National Geographic and Science were listening in.

Genetics: Evolution and medicine across Africa

Variability in the gene encoding the drug metabolizing enzyme Cytochrome P450 3A5 (CYP3A5) from 36 ethnically diverse populations in Africa reveals that 43% of individuals express this gene, consistent with it playing a role in salt-retention. Lead author of the study Ripudaman K Bains from University College London outlines how understanding our evolutionary past could help guide drug therapies of the future.

Medical ethics: Is it right to recruit by genotype?

A debate article discusses some of the issues surrounding Genotype-Based Recruitment – a study design that allocates clinical trial participants based on their genotypes, rather than clinical conditions. Isabelle Budin-Ljøsne and colleagues suggest that the existing recommendations for recruitment of such studies are not sufficient for a broader use of this design, and highlight the issues that will require more coordinated solutions in the future.

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