Search results for "OTA"

2017

The endosymbiotic bacterium Wolbachia is the most widespread bacteria in insects, yet the ecology of novel acquisitions in natural host populations is poorly understood. Using temporal data separated by 12 years, I tested the hypothesis that immigration of a parasitoid wasp led to transmission of its Wolbachia strain to its dipteran host, resulting in double-strain infection, and I used geographic and community surveys to explore the history of transmission in fly and parasitoid. Double infection in the fly host was present before immigration of the parasitoid. Equal prevalence of double infection in males and females, constant prevalence before and after immigration in two regions, and inc…

The evolutionary ecology of deception

2015

Through dishonest signals or actions, individuals often misinform others to their own benefit. We review recent literature to explore the evolutionary and ecological conditions for deception to be more likely to evolve and be maintained. We identify four conditions: (1) high misinformation potential through perceptual constraints of perceiver; (2) costs and benefits of responding to deception; (3) asymmetric power relationships between individuals and (4) exploitation of common goods. We discuss behavioural and physiological mechanisms that form a deception continuum from secrecy to overt signals. Deceptive tactics usually succeed by being rare and are often evolving under co-evolutionary a…

Fluctuating Asymmetry in Central and Marginal Populations of Lychnis viscaria in Relation to Genetic and Environmental Factors

1998

Developmental instability in the form of increased fluctuating asymmetry can be caused by either genetic or environmental stress. Because extinctions can be attributed broadly to these factors, fluctuating asymmetry may provide a sensitive tool for detecting such stresses. We studied the level of fluctuating asymmetry of flowers of a perennial outcrossing plant species, Lychnis viscaria, both in natural and common-garden populations. The degree of flower asymmetry was higher in small, isolated, and marginal populations of the species range. These marginal populations also were the most homozygous. In the core area of the species' range, flowers were more symmetrical The level of asymmetry w…

The Philippine Agriculture: Weaknesses and Controversies

2017

The sugarcane plantations of Negros Island epitomize the huge inequalities in the Philippine countryside. Landlords have controlled vast estates, the haciendas, since the Spanish colonial period. Despite the pressure of peasant associations, revolutionary agrarian movements (Huks, then the communist NPA) and the church support for poor farmers, most efforts to implement a substantial agrarian reform, including in the Marcos period and the CARP of Corazon Aquino, have failed in reducing inequities and improving the life of poor peasants in the country. Hacienda Luisita, a property of the Aquino family, illustrates the difficulties to implement a true agrarian reform. The Philippines hence ap…

Potential of science to address the hunger issue: Ecology, biotechnology, cattle breeding and the large pantry of the sea

2018

The knowledge about the real possibilities that current science gives us is basic to support everything that is not negative either for men or for our environment. In this way, it is an advantage to win this battle against hunger with rational use of science advantages. In this paper, we start from the basis that the solution to the problems of hunger requires the multidisciplinary action of sciences and knowledge. We provide a reflection on the possibilities to be considered from disciplines such as ecology, biotechnology, veterinary and aquaculture. The need for ecological studies where the role of human beings as part of ecosystems is considered. In addition, advances in molecular biolog…

Microspore embryogenesis induced through in vitro anther culture of almond (Prunus dulcis Mill.)

2016

Anther culture is one of the most widely used methods to induce gametic embryogenesis. The aim of this investigation was to induce microspore embryogenesis in almond (Prunus dulcis Mill.), through this technique. Anthers were cultured at the vacuolated developmental stage, and seven cultivars, two culture media and two temperature treatments were assessed. Although evidence of the microspore induction was observed in all the genotypes and treatments tested (symmetrical nucleus division and multinucleated structures), calli were produced merely by anthers cultured in the medium P and the regeneration of embryos was detected only in anthers of the cultivars Filippo Ceo, Lauranne and Genco, pl…

Loss of Arabidopsis p24 function affects ERD2 traffic and Golgi structure and activates the unfolded protein response

2017

The p24 family of proteins (also known as the TMED family) are key regulators of protein trafficking along the secretory pathway, but very little is known about their functions in plants. A quadruple loss-of-function mutant affecting the p24 genes from the δ-1 subclass of the p24δ subfamily (p24δ3δ4δ5δ6) showed alterations in the Golgi, suggesting that these p24 proteins play a role in the organization of the compartments of the early secretory pathway in Arabidopsis Loss of p24δ-1 proteins also induced the accumulation of the K/HDEL receptor ERD2a (ER lumen protein-retaining receptor A) at the Golgi and increased secretion of BiP family proteins, ER chaperones containing an HDEL signal, pr…

Microbial symbionts expanding or constraining abiotic niche space in insects

2020

In addition to their well-studied contributions to their host’s nutrition, digestion, and defense, microbial symbionts of insects are increasingly found to affect their host’s response toward abiotic stressors. In particular, symbiotic microbes can reduce or enhance tolerance to temperature extremes, improve desiccation resistance by aiding cuticle biosynthesis and sclerotization, and detoxify heavy metals. As such, individual symbionts or microbial communities can expand or constrain the abiotic niche space of their host and determine its adaptability to fluctuating environments. In light of the increasing impact of humans on climate and environment, a better understanding of host-microbe …

Patterns of the lemma micromorphology : a useful tool in taxonomy of the middle Asian Eragrostis species (Poaceae)

2017

We examined all taxa of the genus Eragrostis noted so far in Middle Asia, namely: Eragrostis amurensis, Eragrostis cilianensis, Eragrostis minor agg., Eragrostis pilosa and Eragrostis virescens. By means of scanning electron microscope, such structures as long cells, short cells (cork and silica cells), prickles, microhairs and glands were scrutinized and compared among taxa. Additionally, several macromorphological characteristics were investigated. Principal component analysis and cluster analysis were conducted in order to reveal the morphological relationships and differences among species. Micromorphology of the lemma epidermis, together with selected macromorphological characteristics…

From the roots to the stem: unveiling pear root colonization and infection pathways by Erwinia amylovora

2020

ABSTRACT Fire blight caused by Erwinia amylovora affects pome fruit worldwide, generating serious economic losses. Despite the abundant literature on E. amylovora infection mechanisms of aerial plant organs, root infection routes remain virtually unexplored. Assessing these infection pathways is necessary for a full understanding of the pathogen's ecology. Using the pathosystem Pyrus communis–E. amylovora and different experimental approaches including a green fluorescent protein transformant (GFP1) and epifluorescence microscopy (EFM) and laser confocal scanning microscopy (LCSM), we demonstrated the pathogen's ability to infect, colonize and invade pear roots and cause characteristic fire…