The mammalian accessory olfactory system is critical for the detection and identification of pheromones and the representation of complex stimuli including sex, genetic relatedness, and individual identity. Mitral cells, the principal cells of the accessory olfactory bulb (AOB), receive monosynaptic input from the sensory periphery and already show highly specific response properties, firing se...

Ammonia-oxidizing bacteria (AOB) can use oxygen and nitrite as electron acceptors. Nitrite reduction by Nitrosomonas is observed under three conditions: (i) hydrogen-dependent denitrification, (ii) anoxic ammonia oxidation with nitrogen dioxide (NO(2)) and (iii) NO(x)-induced aerobic ammonia oxidation. NO(x) molecules play an important role in the conversion of ammonia and nitrite by AOB. Absen...

Ammonia-oxidizing bacteria (AOB) and archaea (AOA) were quantified in the sediments and roots of dominant macrophytes in eight neutral to alkaline coastal wetlands. The AOA dominated in most samples, but the bacterial-to-archaeal amoA gene ratios increased with increasing ammonium levels and pH in the sediments. For all plant species, the ratios increased on the root surface relative to the adj...

Pheromone detection by the vomeronasal organ (VNO) is thought to rely on activation of specific receptors from the V1R and V2R gene families, but the central representation of pheromone receptor activation remains poorly understood. We generated transgenic mouse lines in which projections from multiple populations of VNO neurons, each expressing a distinct V1R, are differentially labeled with f...

Water availability is the main limiting factor in arid soils; however, few studies have examined the effects of drying and rewetting on nitrifiers from these environments. The effect of water availability on the diversity of ammonia-oxidizing bacteria (AOB) and archaea (AOA) from a semiarid soil of the Chilean sclerophyllous matorral was determined by microcosm assays. The addition of water eve...

Trait-based microbial models show clear promise as tools to represent the diversity and activity of microorganisms across ecosystem gradients. These models parameterize specific traits that determine the relative fitness of an "organism" in a given environment, and represent the complexity of biological systems across temporal and spatial scales. In this study we introduce a microbial community...

The Grain to Green Project (GGP) is an unprecedented land restoration action in China. The project converted large areas (ca 10 million ha) of steep-sloped/degraded farmland and barren land into forest and grassland resulting in ecological benefits such as a reduction in severe soil erosion. It may also affect soil microorganisms involved in ammonia oxidization, which is a key step in the globa...

The community of ammonia-oxidizing prokaryotes was examined in an agricultural soil treated for six seasons with contrasting nitrogen (N) sources. Molecular tools based on the genes encoding ammonia monooxygenase were used to characterize the ammonia oxidizer (AO) communities and their abundance. Soil DNA was extracted from soils sampled from silage corn plots that received no additional N (con...

To analyze the mechanisms of perception and processing of pheromonal signals in vitro, we previously developed a new culture system for vomeronasal receptor neurons (VRNs), referred to as the vomeronasal pocket (VN pocket). However, very few VRNs were found to express the olfactory marker protein (OMP) and to have protruding microvilli in VN pockets, indicating that these VRNs are immature and ...

Despite their crucial role in the nitrogen cycle, freshwater ecosystems are relatively rarely studied for active ammonia oxidizers (AO). This study of Lake Lucerne determined the abundance of both amoA genes and gene transcripts of ammonia-oxidizing archaea (AOA) and bacteria (AOB) over a period of 16 months, shedding more light on the role of both AO in a deep, alpine lake environment. At the ...