Offspring Hormones Reflect the Maternal Prenatal Social Environment: Potential for Foetal Programming?

Females of many species adaptively program their offspring to predictable environmental conditions, a process that is often mediated by hormones. Laboratory studies have shown, for instance, that social density affects levels of maternal cortisol and testosterone, leading to fitness-relevant changes in offspring physiology and behaviour. However, the effects of social density remain poorly understood in natural populations due to the difficulty of disentangling confounding influences such as climatic variation and food availability. Colonially breeding marine mammals offer a unique opportunity to study maternal effects in response to variable colony densities under similar ecological conditions. We therefore quantified maternal and offspring hormone levels in 84 Antarctic fur seals (Arctocephalus gazella) from two closely neighbouring colonies of contrasting density. Hair samples were used as they integrate hormone levels over several weeks or months and therefore represent in utero conditions during foetal development. We found significantly higher levels of cortisol and testosterone (both P < 0.001) in mothers from the high density colony, reflecting a more stressful and competitive environment. In addition, offspring testosterone showed a significant positive correlation with maternal cortisol (P < 0.05). Although further work is needed to elucidate the potential consequences for offspring fitness, these findings raise the intriguing possibility that adaptive foetal programming might occur in fur seals in response to the maternal social environment. They also lend support to the idea that hormonally mediated maternal effects may depend more strongly on the maternal regulation of androgen rather than cortisol levels

New Human Papilloma Virus E2 Transcription Factor Mimics: A Tripyrrole-Peptide Conjugate with Tight and Specific DNA-Recognition

BACKGROUND: Human papillomavirus (HPV) is the main causative agent of cervical cancer, particularly high risk strains such us HPV-16, -18 and -31. The viral encoded E2 protein acts as a transcriptional modulator and exerts a key role in viral DNA replication. Thus, E2 constitutes an attractive target for developing antiviral agents. E2 is a homodimeric protein that interacts with the DNA target through an α-helix of each monomer. However, a peptide corresponding to the DNA recognition helix of HPV-16 E2 binds DNA with lower affinity than its full-length DNA binding domain. Therefore, in an attempt to promote the DNA binding of the isolated peptide, we have designed a conjugate compound of the E2 α-helix peptide and a derivative of the antibiotic distamycin, which involves simultaneous minor- and major-groove interactions. METHODOLOGY/PRINCIPAL FINDINGS: An E2 α-helix peptide-distamycin conjugate was designed and synthesized. It was characterized by NMR and CD spectroscopy, and its DNA binding properties were investigated by CD, DNA melting and gel shift experiments. The coupling of E2 peptide with distamycin does not affect its structural properties. The conjugate improves significantly the affinity of the peptide for specific DNA. In addition, stoichiometric amounts of specific DNA increase meaningfully the helical population of the peptide. The conjugate enhances the DNA binding constant 50-fold, maintaining its specificity. CONCLUSIONS/SIGNIFICANCE: These results demonstrate that peptide-distamycin conjugates are a promising tool to obtain compounds that bind the E2 target DNA-sequences with remarkable affinity and suggest that a bipartite major/minor groove binding scaffold can be a useful approach for therapeutic treatment of HPV infection

Nutrition, productivity and soil chemical properties in an apple orchard under weed management

Weed management in orchard may affect apple tree nutritional status and yield, N flow and other soil chemical properties. This study evaluated apple tree nutritional status and yield, N flow in soil and soil chemical properties in an apple orchard under different weed managements. The experiment was started in October 2011 in an apple orchard established in 2008, on 80 plants submitted to the following treatments: no weed management, weed desiccation in rows, weed mowing in rows and weed mowing in rows and interrows. In 2011/2012, 2012/2013, and 2013/2014 crop seasons, stem diameter, number of fruits per plant and yield were measured, and nutrient leaf concentrations were quantified. In 2012/2013 and 2013/2014 crop seasons, soil samples were collected from 0 to 0.20 m layers, in order to quantify NH4 ?–N and NO3 -–N. In September 2013, 24 months after beginning of the experiment, stratified soil samples were collected in the 0–0.025, 0.025–0.05, 0.05–0.10, 0.10–0.15, 0.15–0.20 and 0.20–0.40 m layers. Soil total organic carbon, pH, available P and exchangeable K, Ca, and Mg were measured. The weed management methods did not affect apple tree yield and growth and they had a small effect on nutrient concentrations in leaves and in soil. Row and inter-row weed management had little or no effect on competition with apple trees for water and nutrients. The weed management can be dispensed during the production cycle, reducing soil erosion, N losses and the use of herbicide