SummaryPlants challenged by limited phosphorus undergo dramatic morphological and architectural changes in their root systems in order to increase their absorptive surface area. In this paper, it is shown that phosphorus deficiency results in increased expression of the type I

Semiconductor nanocrystal quantum dots (QDs) allow long-term imaging in the cellular environment with high photostability. QD biolabeling techniques have previously been developed for tagging proteins and peptides as well as oligonucleotides. In this contribution, QD-decorated plasmid DNA was utilized for the first time for long-term intracellular and intranuclear tracking studies. Conjugation of plasmid DNA with phospholipid-coated QDs was accomplished using a peptide nucleic acid (PNA)-N-succinimidyl-3-(2-pyridylthio) propionate linker. Gel electrophoresis and confocal and atomic force microscopy (AFM) were used to confirm the structure of QD-DNA conjugates. AFM imaging also revealed that multiple QDs were attached in a cluster at the PNA-reactive site of the plasmid DNA. These QD-DNA conjugates were capable of expressing the reporter protein, enhanced green fluorescent protein, following transfection in Chinese hamster ovary (CHO-K1) cells with an efficiency of ca. 62%, which was comparable to the control (unconjugated) plasmid DNA.

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, the primary etiologic agent of chronic respiratory disease (CRD) in poultry, leads to prolonged recruitment and activation of inflammatory cells in the respiratory mucosa. This is consistent with the current model of immune dysregulation that ostensibly allows the organism to evade clearance mechanisms and establish chronic infection. To date, studies using quantitative reverse transcription-PCR (qRT-PCR) and microarrays have shown a significant transient upregulation of cytokines and chemokines from tracheal epithelial cells (TECs) and tracheal tissue in response to virulent strain R that contributes to the infiltration of inflammatory cells into the tracheal mucosa. To expand upon these experiments, RNA was isolated from tracheas of 20 chickens infected with R and 20 mock-infected animals at days 1, 3, 5, and 7 postinoculation, and samples were analyzed for differential gene expression using Illumina RNA sequencing. A rapid host response was observed 24 h postinfection, with over 2,500 significantly differentially expressed genes on day 3, the peak of infection. Many of these genes have immune-related functions involved in signaling pathways, including Toll-like receptor (TLR), mitogen-activated protein kinase, Jak-STAT, and the nucleotide oligomerization domain-like receptor pathways. Of interest was the increased expression of numerous cell surface receptors, including TLR4 and TLR15, which may contribute to the production of cytokines. Metabolic pathways were also activated on days 1 and 3 postinfection, ostensibly due to epithelial cell distress that occurs upon infection. Early perturbations in tissue-wide gene expression, as observed here, may underpin a profound immune dysregulation, setting the stage for disease manifestations characteristic of infection.

Colonization of the avian respiratory tract with Mycoplasma gallisepticum results in a profound inflammatory response in the trachea, air sacs, conjunctiva, and lungs. A live attenuated M. gallisepticum vaccine strain, GT5, was previously shown to be protective in chickens upon challenge; however, the mechanisms by which this vaccine and others confer protection remain largely unknown. The current study evaluated several potential correlates of GT5 vaccine-mediated immune protection following challenge with the pathogenic M. gallisepticum strain R low . GT5-vaccinated chickens developed mild tracheal lesions, consisting of few and scattered, discrete, lymphofollicular aggregates in the lamina propria. In addition, low numbers of aggregated B, CD4؉ , and CD8 Mycoplasma gallisepticum is a highly infectious respiratory pathogen affecting poultry. When present in concert with other respiratory pathogens such as infectious bronchitis virus, Newcastle disease virus, Escherichia coli, or Haemophilus paragallinarum, a condition known as chronic respiratory disease results. The clinical signs associated with M. gallisepticum infection in chickens include respiratory rales, nasal discharge, coughing, and occasionally conjunctivitis (20). The most prominent pathological findings include inflammatory lesions in the trachea, air sacs, lungs, conjunctiva, and other tissues such as the oviduct (25). Significant economic losses from M. gallisepticum infection in poultry occur due to reduced egg production and hatchability, as well as downgrading of carcasses (20). Mycoplasma gallisepticum transmission can occur both horizontally through aerosols and vertically through the egg, leading to a rapid spread within the flock. Control programs for M. gallisepticum infection are based on maintaining a commercial breeding stock that is M. gallisepticum free and rearing them in single-aged, all-in/all-out farms. However, in multiple-age production complexes, administration of suitable antibiotic medication is practiced to reduce production losses and egg transmission (18). Eradication by means of vaccination is also one of the preferred methods of control under such circumstances.Previously, bacterins and live vaccines have been commercially used for the control of M. gallisepticum infection in chickens (35). Killed whole-cell M. gallisepticum bacterins reduced the severity of lesions and egg production losses but did not completely prevent M. gallisepticum colonization of the chicken respiratory tract upon challenge (14, 37). At the same time, bacterins fail to provide complete protection against heterologous exposure. Over the past decade, the use of bacterins has been supplanted by more effective live attenuated vaccines. Three live attenuated vaccines (ts-11, 6/85, and F-strain) have been commercialized and have shown a high degree of efficacy in controlling the dissemination of disease (1,6,15,35). Little is known regarding the genetic basis of attenuation in these strains, as well as the immune mechanisms by which protection is con...