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General and Comparative Endocrinology

Carolyn M Bauer, Loreto A Correa, Luis A Ebensperger, L Michael Romero
The Common Degu (Octodon degus) is a small rodent endemic to central Chile. It has become an important model for comparative vertebrate endocrinology because of several uncommon life-history features - it is diurnal, shows a high degree of sociality, practices plural breeding with multiple females sharing natal burrows, practices communal parental care, and can easily be studied in the laboratory and the field. Many studies have exploited these features to make contributions to comparative endocrinology. This review summarizes contributions in four major areas...
March 12, 2018: General and Comparative Endocrinology
Andrew M Holmes, Christopher J Emmans, Robert Coleman, Tessa E Smith, Charlotte A Hosie
Understanding the immediate and longer-term effects of transportation and re-housing in a laboratory species is crucial in order to refine the transfer process, enable the optimal introduction of new animals to a novel environment and to provide a sufficient acclimatisation period before usage. Whilst consideration of animal welfare in most model vertebrate species has received attention, little quantitative evidence exists for the optimal care of the common laboratory amphibian Xenopus laevis. Techniques for the non-invasive welfare assessment of amphibians are also limited and here a non-invasive physiological assay was developed to investigate the impacts of transportation, transport medium and re-housing on X...
March 12, 2018: General and Comparative Endocrinology
T Porseryd, N Reyhanian Caspillo, K Volkova, L Elabbas, T Källman, P Dinnétz, P-E Olsson, I Porsch-Hällström
17α-Ethinylestradiol (EE2 ) is a ubiquitous aquatic contaminant shown to decrease fish fertility at low concentrations, especially in fish exposed during development. The mechanisms of the decreased fertility are not fully understood. In this study, we perform transcriptome analysis by RNA sequencing of testes from zebrafish with previously reported lowered fertility due to exposure to low concentrations of EE2 during development. Fish were exposed to 1.2 and 1.6 ng/L (measured concentration; nominal concentrations 3 and 10 ng/L) of EE2 from fertilization to 80 days of age, followed by 82 days of remediation in clean water...
March 8, 2018: General and Comparative Endocrinology
Yi-Xiang Qi, Tian Zeng, Lei Wang, Yong-Yue Lu
The red imported fire ant, Solenopsis invicta Buren, is a dangerous invasive pest in the United States, China and other countries. Efficient division of labor is one of the main reasons for the success of this social insect. Biogenic amines are important regulators of worker division of labor in this eusocial insect, but the related molecular mechanisms are largely unknown. In this study, we identified 10 candidate biogenic amine synthetic enzyme genes and 17 candidate biogenic amine receptor genes in the genome of S...
March 8, 2018: General and Comparative Endocrinology
Robert M Dores, Michelle Scuba-Gray, Bridgette McNally, Perry Davis, Akiyoshi Takahashi
Previous studies on bony vertebrate MC2R orthologs (i.e., ray finned fishes, amphibians, reptiles, birds, and mammals) have shown that these MC2R orthologs have an obligatory requirement for interaction with bony vertebrate MRAP1 orthologs to a) allow for the trafficking of the MC2R ortholog to the plasma membrane; and b) to allow activation by ACTH, but not by any MSH-sized ligand. In addition, previous studies have found that co-expression of teleost and mammalian MC4R orthologs with corresponding MRAP2 has positive effects on sensitivity to stimulation by αMSH or ACTH...
March 7, 2018: General and Comparative Endocrinology
Miwa Suzuki, Kaho Banno, Toshiki Usui, Noriko Funasaka, Takao Segawa, Tetsuo Kirihata, Haruka Kamisako, Keiichi Ueda, Arimune Munakata
In general, thyroid hormones (THs) stimulate cellular metabolism by inducing ATP utilization that collaterally leads to thermogenesis. However, in cetaceans, TH functions and the contribution of THs to cold adaptation are not fully understood. To investigate the role of THs in metabolism of cetaceans, seasonal changes in circulating levels in thyroxine (T4 ) were investigated in the common bottlenose dolphin Tursiops truncatus that were monitored under two different conditions for two years, with routine measurements of body temperature (BT), water temperature (WT) and air temperature (AT)...
March 7, 2018: General and Comparative Endocrinology
Huafeng Zou, Zhaohui Lan, Mo Zhou, Weiqun Lu
The peptide urotensin II (UII) mediates multiple physiology effects in mammals and fishes, and UII expression showed a tissue-specific pattern. However the mechanism is still unknown. In the present study high level of UII mRNA was detected in the caudal neurosecretory system (CNSS) of the olive flounder when compared to other tissues. We examined whether epigenetic mechanisms of DNA methylation are involved in UII gene expression. Methylation DNA immune precipitation (MeDIP) assay showed low methylation of UII promoter in CNSS tissue compared with muscle and spinal cord...
March 6, 2018: General and Comparative Endocrinology
A A Szczepańska, M Łupicka, B M Socha, A J Korzekwa
Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the superfamily of nuclear receptors. Three isoforms have been described: alpha (PPARα), delta (PPARδ), and gamma (PPARγ). PPARs heterodimerize with retinoid X receptors (RXRs: RXRα, RXRβ and RXRγ). PPAR activity can be modulated by several ligands, including arachidonic acid (AA) metabolites. The aims of the study were to determine the effect of AA metabolites (prostaglandin [PG]E2 , PGF2α , leukotriene [LT]B4 , and LTC4 ) on mRNA (real-time PCR) and protein expression (Western blotting) of PPARα, PPARδ, and PPARγ, and on mRNA expression of RXRα, RXRβ, and RXRγ, in bovine epithelial, stromal, and myometrial primary uterine cells and in bovine stromal cells with silenced PPAR genes (N=10)...
March 3, 2018: General and Comparative Endocrinology
Ryo Nozu, Kiyomi Murakumo, Nagisa Yano, Rina Furuyama, Rui Matsumoto, Makio Yanagisawa, Keiichi Sato
Captive breeding in aquaria is a useful means for ex situ preservation of threatened elasmobranch species. To promote captive breeding, it is important to determine the female reproductive status. However, information regarding reproductive status in female elasmobranchs is limited. Here, we used zebra sharks, Stegostoma fasciatum, as a model for elasmobranch reproduction in captivity. We investigated the relationships among changes in the sex steroid hormone levels, follicle size, and egg-laying period to develop indicators for the female reproductive status...
March 3, 2018: General and Comparative Endocrinology
Shaohua Sun, Jing Cai, Wenjing Tao, Limin Wu, Chakraborty Tapas, Linyan Zhou, Deshou Wang
17α, 20β-dihydroxypregn-4-en-3-one (17α, 20β-DP, DHP), a teleost specific biologically active progestin, has been proved to play a critical role in oocytes maturation, ovulation and spermiation. RU486 (Mifepristone, an antagonist of progestin receptor) has been applied in contraceptives, abortion and hormone therapy in clinical medicine. To get further insights into the molecular mechanisms of nuclear progestin receptor (Pgr) activated ovarian differentiation and maintenance, we conducted comparative gonadal transcriptome analysis, and investigated histological and transcriptional differences using 4 mah (month after hatching) RU486-treated XX and control XX/XY Nile tilapia (Oreochromis niloticus)...
March 3, 2018: General and Comparative Endocrinology
Takayoshi Ubuka, Ishwar S Parhar, Kazuyoshi Tsutsui
Gonadotropin-inhibitory hormone (GnIH) is an inhibitor of the hypothalamic-pituitary-gonadal (HPG) axis. GnIH is also called RFamide-related peptide (RFRP) as GnIH peptides have a characteristic C-terminal LPXRFiamide (X = L or Q) sequence. GnIH is thought to be the mediator of stress by negatively regulating the HPG axis as various stressors increase GnIH mRNA, GnIH peptide or GnIH neuronal activity. On the other hand, GnIH may also mediate behavioral stress responses as GnIH neuronal fibers and GnIH receptors are widely located in the limbic system of telencephalon, diencephalon and midbrain area...
March 3, 2018: General and Comparative Endocrinology
David M Irwin, Svetlana Mojsov
The teleost fish-specific genome duplication gave rise to a great number of species inhabiting diverse environments with different access to nutrients and life histories. This event produced duplicated gcg genes, gcga and gcgb, for proglucagon-derived peptides, glucagon and GLP-1 and duplicated gcgr receptor genes, gcgra and gcgrb, which play key roles connecting the consumption of nutrients with glucose metabolism. We conducted a systematic survey of the genomes from 28 species of fish (24 bony (Superclass Osteichthyes), 1 lobe-finned (Class Sarcoperygii), 1 cartilaginous (Superclass Chondrichthyes), and 2 jawless (Superclass Agnatha)) and find that almost all surveyed ray-finned fish contain gcga and gcgb genes with different coding potential and duplicated gcgr genes, gcgra and gcgrb that form two separate clades in the phylogenetic tree consistent with the accepted species phylogeny...
March 3, 2018: General and Comparative Endocrinology
Guoqing Wang, Mark A Cline, Elizabeth R Gilbert
The goal of this research was to determine the effect of dietary macronutrient composition on peripheral neuropeptide Y (NPY)-induced changes in adipose tissue dynamics in chicks. Chicks were fed one of three isocaloric diets from the day of hatch: high carbohydrate (HC), high fat (HF), or high protein (HP). On day 4 post-hatch, 0 (vehicle), 60, or 120 µg/kg BW of NPY was injected intraperitoneally, and subcutaneous, clavicular and abdominal adipose tissue samples were collected at 1 and 3 h post-injection...
March 3, 2018: General and Comparative Endocrinology
Hu Shu, Lidong Yang, Yong Zhang, Xiaochun Liu, Haoran Lin, Shuisheng Li
Secretoneurin (SN) is an important stimulator of pituitary luteinizing hormone (LH) synthesis and secretion in goldfish. It is unknown whether this neuropeptide performs the same role in other fish species. In this study, the full-length cDNAs encoding Secretogranin IIa (SgIIa) and b (SgIIb) were cloned from the brain of orange-spotted grouper. Sequence analysis showed that a 34-amino acid SN peptide (SNa) is present in SgIIa proprotein, and a 33-amino acid SN peptide (SNb) is present in SgIIb proprotein. The two SN peptides share a low degree of similarity but contain the signature YTPQ-X-LA-X7 -EL sequence...
February 24, 2018: General and Comparative Endocrinology
Lei Zhihai
Neuropeptide B (NPB) is an endogenous ligand for the orphan G protein-coupled receptors NPBWR1 (GPR7) and NPBWR2 (GPR8). Some reports have investigated the role of NPB in the regulation of feeding, energy metabolism and hormone secretion in many species. However, few papers reported the physiological function of NPB in the pig. In this study, we cloned and sequenced the NPB mRNA from a pig, which was found to consist of 123 bases. NPB mRNA expression was detected in central and peripheral tissues by the quantitative fluorescence method...
February 23, 2018: General and Comparative Endocrinology
Melissa Duarte-Méndez, Jennifer Quintero-Silva, Martha Patricia Ramírez-Pinilla
In squamates, progesterone (P) plays a key role in the inhibition of uterine mobility during egg retention in oviparous species, and during gestation in viviparous species. The corpus luteum (CL) is the main organ responsible for the production of P; however, in some species, the CL degenerates early and the P needed for gestation maintenance should be produced in other tissues. Mabuya sp (Scincidae) is a viviparous lizard with a prolonged gestation, it produces microlecithal eggs and, consequently, has an obligate placentotrophy related with a highly complex placenta...
February 22, 2018: General and Comparative Endocrinology
Marcia Valenzuela-Molina, Shannon Atkinson, Kendall Mashburn, Diane Gendron, Robert L Brownell
Steroid hormone assessment using non-invasive sample collection techniques can reveal the reproductive status of aquatic mammals and the physiological mechanisms by which they respond to changes in their environment. A portion of the eastern North Pacific blue whale (Balaenoptera musculus) population that seasonally visits the Gulf of California, Mexico has been monitored using photo-identified individuals for over 30 years. The whales use the area in winter-early spring for nursing their calves and feeding and it therefore is well suited for fecal sample collection...
February 21, 2018: General and Comparative Endocrinology
Anuradha, Amitabh Krishna
The aim of the present study was to evaluate the mechanism by which embryonic development in Cynopterus sphinx is impaired during the period of increased accumulation of white adipose tissue during winter scarcity of food. The change in the mass of white adipose tissue during adipogenesis showed significant positive correlation with the circulating glucose level. But increase in circulating glucose level during the adipogenesis showed negative correlation with circulating progesterone and adiponectin levels...
February 20, 2018: General and Comparative Endocrinology
Teesha C Luehr, Emily M Koide, Xiaodong Wang, Jun Han, Christoph H Borchers, Caren C Helbing
Anuran metamorphosis involves the transformation of an aquatic tadpole into a juvenile frog. This process is completely dependent upon thyroid hormones (THs). Although much research has been focused on changes in gene expression programs during this postembryonic developmental period, transitions in the metabolic profiles are relatively poorly understood. Matrix Assisted Laser Desorption/Ionization-Mass Spectrometry Imaging (MALDI-MSI) is a technique that generates highly multiplexed mass spectra while retaining spatial location information on a thin tissue section...
February 19, 2018: General and Comparative Endocrinology
Gang Liu, Xiaolong Hu, Aimee Elizabeth Kessler, Minghao Gong, Yihua Wang, Huixin Li, Yuqiu Dong, Yuhui Yang, Linhai Li
Birds use both the corticosterone stress response and immune system to meet physiological challenges during exposure to adverse climatic conditions. To assess the stress level and immune response of the Asian Great Bustard during conditions of severe winter weather, we measured fecal corticosterone (CORT) and Immunoglobulin A (IgA) before and after snowfall in a low snow cover year (2014) and a high snow cover year (2015). A total of 239 fecal samples were gathered from individuals in Tumuji Nature Reserve, located in eastern Inner Mongolia, China...
February 17, 2018: General and Comparative Endocrinology
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