Studies have demonstrated an effect of yolk testosterone levels on the physiology and behavior of nestling birds. In order to investigate this phenomenon experimentally in a precocial bird, we enhanced yolk testosterone, but within the physiological range, by injecting 50 ng testosterone in ethanol into Japanese quail Coturnix japonica eggs prior to incubation. The chicks hatching from these as well as from control eggs that had received the carrier-only or were left unmanipulated were subject to a number of behavioral tests from hatching to the age of 3 weeks. In addition, fecal samples were taken during a 90-min isolation period to determine a physiological response to a stressor. Experimental chicks performed a detour task faster and approached novel objects sooner than did the controls. Chicks from treated eggs took a longer time to start distress vocalizing and also produced less distress calls during open-field trials, took on average a larger number of trials for them to show tonic immobility and also excreted lower levels of corticosterone metabolites (BM) than did the controls. In response to a stressor, excreted BM was initially higher in the control chicks, as compared to the experimental birds. Induced behavioral effects were independent of sex with no sex treatment interactions found. In sum, experimentally enhanced testosterone levels in the eggs shifted individual behavioral phenotype towards "bold" or "proactive", irrespective of sex. We conclude that testosterone in the yolk influences the coping style of hatchlings and may be a potential means of maternal influence on offspring phenotype.
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http://dx.doi.org/10.1016/j.yhbeh.2004.09.006 | DOI Listing |
Mol Ecol
January 2025
Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.
J Anim Ecol
November 2024
School of Biological Sciences, University of Oklahoma, Norman, Oklahoma, USA.
The prenatal transfer of testosterone (T) from mother to offspring is an important source of phenotypic plasticity. In birds, exposure to ecologically relevant stimuli, such as social competition or an attractive mate, can cause females to deposit more T into their egg yolks. Exposure to elevated yolk T can modify the expression of several fitness-related traits in offspring (e.
View Article and Find Full Text PDFHorm Behav
July 2024
School of Biological Sciences, University of Oklahoma, Norman, OK 73019, USA; Department of Biology, Indiana University, Bloomington, IN 47405, USA. Electronic address:
Offspring from females breeding in competitive social environments are often exposed to more testosterone (T) during embryonic development, which can affect traits from growth to behavior in potentially adaptive ways. Despite the important role of maternally derived steroids in shaping offspring development, the molecular mechanisms driving these processes are currently unclear. Here, we use tree swallows (Tachycineta bicolor) to explore the effects of the maternal social environment on yolk T concentrations and genome-wide patterns of neural gene expression in embryos.
View Article and Find Full Text PDFEnviron Pollut
July 2024
Department of Zoology, Faculty of Science, Al-Azhar University (Assiut Branch), Assiut, 71524, Egypt.
Endocrine disruptors are synthetic or natural chemicals that can agonize/antagonize hormone receptors or can interfere with the production and secretion of hormones, leading to altered tissue histology and physiology. Pyrogallol is a contaminant widely distributed in aquatic environments that presents health risks to both humans and animals. However, the potential for endocrine disruption by pyrogallol, particularly in fish, are lacking.
View Article and Find Full Text PDFBMC Urol
February 2024
Department of Clinical Pharmacology, Affiliated Hangzhou First People's Hospital, Westlake University School of Medicine, Hangzhou, 310006, China.
Background: Extragonadal germ cell tumors originating from the prostate are exceptionally rare. To the best of our knowledge, there have been no reported cases of mixed germ cell tumors in individuals with 46 XX disorder of sex development. In this study, we conducted a comprehensive analysis using whole genome sequencing to investigate the clinicopathological and molecular genetic characteristics of a submitted case, with the objective of elucidating its underlying pathogenesis.
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