H2020Индивидуална стипендия2015–2017

CortFit · Using reaction norms to identify glucocorticoid phenotypes and their relationship to fitness in individuals of a wild vertebrate.

„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“

Период: 2015-04-01 → 2017-03-31
Финансиране от ЕС: 171 461 €
Участници: 1
Схема: MSCA-IF

Линиите свързват координатора с партньорите.

Накратко на български

Глюкокортикоидните хормони при диви гръбначни животни се анализират чрез тестове за стрес и възстановяване. Това помага да се разбере как индивидуалните разлики в хормоналните реакции влияят върху оцеляването и репродуктивния успех при промени в околната среда.

Този кратък обзор е генериран от изкуствен интелект

Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.

Резултати накратко

Using reaction norms to identify glucocorticoid phenotypes and their relationship to fitness in individuals of a wild vertebrate.

Hormones are a key physiological mechanism modulating the response to environmental change, yet understanding about individual variation in hormonal traits is lacking. Recently a novel approach was proposed to study changes in a trait across an environmental gradient, known as a reaction norm (RN). A key characteristic of this approach is the specific focus on plasticity as an important characteristic of an individual’s phenotype, which is critical when studying inherently plastic traits such as hormones. Understanding how hormones modulate the response to environmental change is critical in light of the unprecedented rate at which global change is occurring. Glucocorticoid (GC) hormones are important in modulating the response to energetic challenges at baseline, and in modulating the response to stressors as part of the stress response. Another critical component of the hypothalamic-pituitary-adrenal (HPA) axis, the main physiological system involved in the release of GCs, is a negative feedback loop. Strong negative feedback is deemed important to prevent negative effects of prolonged exposure to elevated GC levels, such as reduced reproductive success and survival. One way to assess HPA axis functioning is the HPA function test, measuring baseline GC, the GC stress response, and negative feedback efficacy through a dexamethasone challenge. Combining the RN approach with the HPA function test provides a comprehensive assessment of the GC flexibility of an individual, which can then be correlated to fitness measures such as reproductive success. The aim of this work was to identify individual GC characteristics that are repeatable and related to reproductive success. The research proposed consists of an interdisciplinary approach using techniques from physiological, behavioral, and evolutionary ecology, as well as from the field of endocrinology. The research undertaken under this project aimed to address two specific objectives: Objective 1: Determine glucocorticoid flexibility of individuals under standardized conditions Objective 2: Determine relationships between glucocorticoid flexibility, reproductive performance and fitness in free-living great tits

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз

Цел на проекта

Environments are currently changing at unprecedented rates, but the evolution of endocrine response mechanisms is still hardly understood. As environmental transducers, hormone levels are plastic, and basic evolutionary questions such as the nature of individually-consistent hormonal traits are still unanswered. The research proposed here embraces hormonal plasticity by using a novel reaction norm approach. Reaction norms are a gold standard in physiological and evolutionary ecology, but have rarely been applied to hormones. Glucocorticoids (GC) mediate environmental responses in many vertebrate traits. Using great tits (Parus major), I will characterize individual GC phenotypes by quantifying GC components and their reaction norms across environmental gradients. These will be assessed repeatedly to test for repeatability, while field studies will explore fitness relationships. I will address four hypotheses: 1) Individuals differ in GC flexibility; 2) Individuals show repeatable GC responses across different contexts and seasons; 3) GCs are related to reproductive success; and 4) GCs modulate reproductive performance. I will quantify GCs at baseline, after capture-restraint and after negative feedback induction in captivity. I will also assess variation in baseline GC along temperature and workload gradients. I will conduct these tests in non-breeding and breeding seasons to calculate repeatability for GC components. I will then adapt these methods to the field, to investigate how GC flexibility correlates with fitness. Finally, I will impose an environmental challenge during the chick-rearing stage by increasing workload to assess GCs and performance. With this novel approach I aim to advance evolutionary endocrinology by identifying individual hormonal characteristics that are repeatable and fitness-relevant. This research represents a topic of high relevance for science and the public and will provide outstanding academic training to an experienced researcher.

Оригинален текст от CORDIS (на английски).

Участници

MAX-PLANCK-GESELLSCHAFT ZUR FORDERUNG DER WISSENSCHAFTEN EV · MUNCHENКоординаторГермания