Stochastic Adaptation to Environmental Changes Supported by Endocrine System Principles

Author(s):  
Dragana Laketic ◽  
Gunnar Tufte ◽  
Pauline Catriona Haddow
2013 ◽  
Vol 9 (4) ◽  
pp. 20130317 ◽  
Author(s):  
Sabrina Tartu ◽  
Aurélie Goutte ◽  
Paco Bustamante ◽  
Frédéric Angelier ◽  
Børge Moe ◽  
...  

Mercury, a ubiquitous toxic element, is known to alter expression of sex steroids and to impair reproduction across vertebrates but the mechanisms underlying these effects are not clearly identified. We examined whether contamination by mercury predicts the probability to skip reproduction in black-legged kittiwakes ( Rissa tridactyla ) from Svalbard. We also manipulated the endocrine system to investigate the mechanism underlying this relationship. During the pre-laying period, we injected exogenous GnRH (gonadotropin-releasing hormone) to test the ability of the pituitary to release luteinizing hormone (LH, a key hormone for the release of sex steroids and hence breeding) in relation to mercury burden. Birds that skipped reproduction had significantly higher mercury concentration in blood than breeders. Endocrine profiles of these birds also varied based on breeding status (breeders versus non-breeders), mercury contamination and sex. Specifically, in skippers (birds that did not breed), baseline LH decreased with increasing mercury concentration in males, whereas it increased in females. GnRH-induced LH levels increased with increasing mercury concentration in both sexes. These results suggest that mercury contamination may disrupt GnRH input to the pituitary. Thus, high mercury concentration could affect the ability of long-lived birds to modulate their reproductive effort (skipping or breeding) according to ongoing environmental changes in the Arctic, thereby impacting population dynamics.


Author(s):  
Yasmine-Marie Cisse ◽  
Jeremy C. Borniger ◽  
Randy J. Nelson

Circadian rhythms permit adaptations to predictable temporal environmental changes. Daily 24-hour rhythms are controlled by molecular clockworks within the brain that are set by the daily light–dark cycle. Downstream endocrine signaling conveys temporal information throughout the body. Mood disorders often present with disruptions in circadian clock-controlled responses, such as sleep and cortisol secretion, whereas circadian rhythm disruptions via jet lag, night-shift work, or light at night increase disordered affective symptoms. Evidence suggests strong associations between circadian rhythms and mental health, but only recently have studies begun to discover the direct interactions between the circadian system and mood regulation. This chapter provides an overview of circadian rhythms and the circadian regulation of the endocrine system. It discusses how the circadian and endocrine systems interact to affect depressive, anxious, and addictive responses. Finally, it discusses the potential detrimental effects the widespread use of nighttime light has for mood and cognition.


2011 ◽  
Vol 47 (2) ◽  
pp. R75-R89 ◽  
Author(s):  
Verónica García-Carpizo ◽  
Lidia Ruiz-Llorente ◽  
Mario Fraga ◽  
Ana Aranda

DNA methylation is the best studied epigenetic factor, playing a key role in producing stable changes in gene expression, thus defining cell identity and function and adapting cells to environmental changes. DNA methylation has also been recently shown to mediate cell responses to physiological endocrine signals. Moreover, alterations of the normal DNA methylation pattern can also contribute to the development of endocrine and metabolic diseases and can explain the relationship between an individual's genetic background, the environment, and disease. It should be remarked that although DNA methylation and demethylation are active processes, epigenetic changes produced during development can impact adult processes, establishing the idea that endocrine function can be persistently affected by events occurring in early life. Given the complexity of the endocrine system, both genetic and epigenetic processes, including DNA methylation, must be involved in its proper development and functioning. In this study, we summarize the recent knowledge in the field of DNA methylation and endocrinology. Given that DNA methylation can be involved in a number of endocrine and metabolic disorders, understanding and manipulating this modification opens a new door for preventing and treating endocrine diseases.


2020 ◽  
Vol 477 (16) ◽  
pp. 3091-3104 ◽  
Author(s):  
Luciana E. Giono ◽  
Alberto R. Kornblihtt

Gene expression is an intricately regulated process that is at the basis of cell differentiation, the maintenance of cell identity and the cellular responses to environmental changes. Alternative splicing, the process by which multiple functionally distinct transcripts are generated from a single gene, is one of the main mechanisms that contribute to expand the coding capacity of genomes and help explain the level of complexity achieved by higher organisms. Eukaryotic transcription is subject to multiple layers of regulation both intrinsic — such as promoter structure — and dynamic, allowing the cell to respond to internal and external signals. Similarly, alternative splicing choices are affected by all of these aspects, mainly through the regulation of transcription elongation, making it a regulatory knob on a par with the regulation of gene expression levels. This review aims to recapitulate some of the history and stepping-stones that led to the paradigms held today about transcription and splicing regulation, with major focus on transcription elongation and its effect on alternative splicing.


2019 ◽  
Vol 3 (5) ◽  
pp. 435-443 ◽  
Author(s):  
Addy Pross

Despite the considerable advances in molecular biology over the past several decades, the nature of the physical–chemical process by which inanimate matter become transformed into simplest life remains elusive. In this review, we describe recent advances in a relatively new area of chemistry, systems chemistry, which attempts to uncover the physical–chemical principles underlying that remarkable transformation. A significant development has been the discovery that within the space of chemical potentiality there exists a largely unexplored kinetic domain which could be termed dynamic kinetic chemistry. Our analysis suggests that all biological systems and associated sub-systems belong to this distinct domain, thereby facilitating the placement of biological systems within a coherent physical/chemical framework. That discovery offers new insights into the origin of life process, as well as opening the door toward the preparation of active materials able to self-heal, adapt to environmental changes, even communicate, mimicking what transpires routinely in the biological world. The road to simplest proto-life appears to be opening up.


2020 ◽  
Vol 11 (1) ◽  
pp. 54-58
Author(s):  
AKM Farhad Hossain ◽  
Md Mahmudur Rahman Siddiqui ◽  
Sayada Fatema Khatun

Background: Thyroid cancer is the most common malignant disease in endocrine system. It is an emerging public health issue associated with burden on the family, community and the nation. The aim of this study is to determine the socio-demographic and clinical characteristics of patient with thyroid cancer attending in tertiary hospital. Methods: This cross sectional study was conducted among 246 thyroid cancer patients in two tertiary hospitals of Dhaka city from 01 July 2018 to 30 June 2019. The subjects were selected purposively following specific selection criteria and maintaining ethical issues. Data were collected by face to face interview using a semi-structured questionnaire and checklist. Data were analyzed by the statistical package for the social science (SPSS) version 23. Results: This study revealed that majority (74.4%) of respondents was female, married (72%), housewife (61.4%), rural respondent (41.1%) and had primary education (69%). Mean (± SD) age of the respondent was 37.85(±12.20) years (Range 14-70 years) and mean (± SD) monthly family income was Tk. 17681(±10602). Out of 246 cases, 204 (82.9%) was papillary and 42 (17.1%) was follicular carcinoma. Various clinical presentations included visible neck swelling in 225 (91.5%), swollen lymph node in 103 (41.9%), pain 90 (36.6%), Difficulties in swallowing 87 (35.4%), Hoarseness of voice in 141 (57.3%), cough along with swelling 47(19.1%), Difficulties in breathing due to swelling in 13(5.3%) of the patients. Conclusion: Incidence of thyroid cancer has increased worldwide specially in female patients in 3rd and 4th decades of life. As thyroid cancer is a growing public health problem in Bangladesh, proper screening and early diagnostic facilities at all level should be available to measure its actual burden in the country. Anwer Khan Modern Medical College Journal Vol. 11, No. 1: Jan 2020, P 54-58


Author(s):  
Ksenya V. Poleshchuk ◽  
Zinaida V. Pushina ◽  
Sergey R. Verkulich

The diatom analysis results of sediment samples from Dunderbukta area (Wedel Jarlsberg Land, West Svalbard) are presented in this paper. The diatom flora consists of four ecological groups, which ratio indicates three ecological zones. These zones show environmental changes of the area in early–middle Holocene that is demonstrating periods of regression and temperature trends.


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