The Role of the Epigenome in Gene Expression Control and the Epimark Changes in Response to the Environment

Our knowledge base involving the biochemical participants of epigenetic control has expanded greatly over the last decade. The role of epigenetic marks to DNA and histones controlled by non-coding RNAs is one of the most intensely studied areas of biology today. This review covers many of the mechanisms that non-coding RNAs and other molecules use to control gene expression and eventually affect responses to the environment. In the first part of the review, we discuss the array of covalent modifications to the genome that constitute the epigenome, which consists of the histone variants, covalent modifications, and post-translational modifications that result in gene expression changes. How the histone variants and post-translational modifications including, acetylation, methylation, phosphorylation, ubiquitination and sumoylation help form the epigenome is also summarized. Our eventual understanding of how the environment controls these modifications will open incredible opportunities in agriculture, medicine and the development of practical tools for biology. In the second part of this review we discuss the growing list of environmentally-mediated epigenetic modifications, and examples of transgenerational epigenetic inheritance events, that may begin to change our views of adaptive responses to the environment and evolution.     

Soil Invertebrates as Bioindicators of Human Disturbance

The aim of this paper is to try to face up to the increasing demand for soil bioindicators to determine the state of health of the environment. Terrestrial ecosystems are contaminated by a wide range of pollutants originating from different sources and having very different distributions. Animals, plants, and, more generally, ecological community patterns seem to be able to register qualitative and quantitative environmental changes due to anthropogenic activities. A clear and accurate definitive generalization of the response of invertebrate populations to direct and indirect environmental stresses is very difficult; many variables can interact, such as the particular invertebrate species and/or the developmental stage exposed to the stress, the particular environmental stress due to different pollutants, and the environmental physical factors as well, sometimes intervening in complex patterns.     

The Italian experience in the control of rabies. II. Laboratory research

Diagnoses of rabies have been performed at the Zooprophylactic Institutes of Brescia and Padua since 1977, 5,765 foxes have been examined and 1,805 (31.30%) resulted positive. The same Institutes have performed also the laboratory tests in order to control the presence of Tetracycline, the serum conversion and the presence of wild or attenuated viruses in the nervous tissue of foxes and other wild animals in occasion of the oral vaccination campaigns of foxes.     

Human kin recognition is self- rather than family-referential

Inclusive fitness theory predicts that organisms will tend to help close kin more than less related individuals. In a variety of birds and mammals, relatives are recognized by comparing their phenotype to an internal representation or template, which might be learned through either repeated exposure to family members or self-inspection. Mirrors are ubiquitous now, but were absent during our evolutionary history; hence it is hard to predict, and empirically unknown, whether human kin recognition is family- or self-referential. Here we put this issue to the strongest possible test by comparing nepotistic behaviour towards self- versus co-twin-resemblant individuals. Seventy monozygotic and dizygotic twins were shown same-sex faces, covertly manipulated to resemble either themselves or their co-twin, and indicated which individual they would prefer in two prosocial contexts. Self-resemblant faces were significantly preferred to twin-resemblant faces, showing that visual information about the self supersedes that about close family members in the kin-recognition template. Because, under conditions of paternal uncertainty, a reliable family-referent template could be based only on one''s mother and maternal relatives, a unique advantage of self-referent phenotype matching is the possibility of (consciously or unconsciously) identifying one''s father and paternal relatives as kin.     

Absence of aluminium compromises root integrity,reduces leaf hydration and Rubisco performance in Qualea grandiflora,an Al-accumulating species

• Aluminium (Al) is toxic to most plants. Nevertheless, some species accumulate Al without showing toxicity symptoms. Previous studies have evidenced Al in chloroplasts of Al-accumulating species from the Cerrado vegetation in South America. We ask whether Al increases carbon assimilation through enhanced apparent efficiency of Rubisco.
• Seedlings of the Al-accumulator Qualea grandiflora (Vochysiaceae) were grown in nutrient solution with 0, 740, and 1480 μm Al. Growth parameters, relative leaf water content, Al concentration in organs, gas exchange and apparent carboxylation efficiency (measured from A/Ci curves) were evaluated for 60 days.
• Plants without Al showed no root growth, necrotic roots, low gas exchange rates, and decreased apparent carboxylation efficiency. Al-treated plants, however, showed new white roots and increased root biomass leading to higher leaf hydration, and apparent carboxylation efficiency was higher in these plants. Increased Al available in the nutrient solution increased Al accumulation in plant organs.
• Absence of Al compromised root integrity in Q. grandiflora, thus limiting leaf hydration. No positive direct effect of Al on Rubisco was evidenced in Al-treated plants.

     

Detection of elastin by immunoelectronmicroscopy

Summary By applying a double-immunolabeling technique to preembedded tissue preparations, we demonstrated the existence of serotoninergic innervation to neurons containing vasoactive intestinal polypeptide (VIP) in the rat suprachiasmatic nucleus (SCN). Immunoreactivity for serotonin and VIP was revealed by the presence of diaminobenzidine (DAB) reaction products and silver-intensified DAB reaction products, respectively; in a further stage, the silver grains were substituted with gold particles. DAB reaction products were precipitated on the surface of vesicular structures, while gold particles were scattered densities. Serotoninergic axons were numerous and closely packed together, occasionally forming synaptic junctions with gold-labeled VIP-containing neurons. At these synaptic junctions, small vesicular structures accumulated to form a coat under the presynaptie membrane, and the postsynaptic membrane was lined with a homogeneous accumulation of fine deposits. This postsynaptic apparatus varied in appearance; some parts were flat and thin, while others were of irregular thickness. Serotoninergic fibers also formed synaptic junctions with unidentified neurons, in which postsynaptic membrane specialization was also observable. As VIP-containing neurons are known to be synapsed by somatostatin (SRIH)-containing neurons, their regulation must involve both serotonin and SRIH at least.