Developmental Instability and Fitness in Periploca laevigata Experiencing Grazing Disturbance

10 páginas, 4 figuras, 4 tablas.We investigated the sensitivity of developmental instability measurements (leaf fluctuating asymmetry, floral radial asymmetry, and shoot translational asymmetry) to a long‐standing natural stress (grazing) in a palatable tannin‐producing shrub (Periploca laevigata Aiton). We also assessed the relationship between these measures of developmental instability and fitness components (growth and floral production). Developmental instability, measured by translational asymmetry, was the most accurate estimator of a plant’s condition and, consequently, environmental stress. Plants with less translational asymmetry grew more and produced more flowers. Plants from the medium‐grazed population were developmentally more stable, as estimated by translational and floral asymmetry, than either more heavily or more lightly grazed populations. Leaf fluctuating asymmetry was positively correlated with tannin concentration. The pattern of internode growth also responded to grazing impact. Plants under medium to heavy grazing pressure accelerated early growth and consequently escaped herbivory later in the season, i.e., at the beginning of the spring, when grazing activity was concentrated in herbaceous plants. Periploca laevigata accelerated growth and finished growing sooner than in the other grazing treatment. Thus, its annual growth was more mature and less palatable later in the season when grazers typically concentrate on shrubs. The reduction of developmental instability under medium grazing is interpreted as a direct effect of grazing and not as the release from competition.The work was realized under the Desertification Risk Assessment in Silvopastoral Mediterranean Ecosystems (DRASME) collaborative research project. DRASME is funded by the European Community under its International Cooperation with Developing Countries Program, contract number ERBIC18‐CT98‐0392. The support from this program is gratefully acknowledged. We are grateful to Dr. T. Navarro and Dr. M. Vrahnakis for critically reading the manuscript and making helpful suggestions. David Navas and Antonio Gonzalez assigned the taxonomic identification of each species, for which we are very grateful. We thank Rosa Jimenez Ortega, Antonio Parra Perez, David Navas, and Antonio Gonzalez for collaborating with us in the collection of data.Peer reviewe

A novel nonsense mutation in the insulin receptor gene in a patient with HAIR-AN syndrome and endometrial cancer

Severe insulin resistance can be caused by rare genetic defects in the insulin receptor known as insulin receptoropathies. These genetic defects cause a wide spectrum of clinical manifestations ranging from mild syndromes to lethal disorders. Among those is the HAIR-AN an extreme subtype of polycystic ovary syndrome (PCOS). We present a case of a 29-year-old woman with amenorrhea, severe insulin resistance, hirsutism, and acanthosis nigricans who also developed endometrial cancer. She was found to carry a novel heterozygous nonsense mutation insulin receptor gene (INSR). The mutation was inherited from the mother. Levels of insulin receptor and AKT were measured using Western-Blot from peripheral blood mononuclear cells and were both decreased. Thus, we conclude that the identified mutation in the insulin receptor gene and lead to decreased activity of the downstream signaling of the insulin pathway