Abstract:
:The sex steroids testosterone (T) and estradiol-17beta (E2) play important roles in vertebrate reproduction and development. However, little is known about the relationship between plasma steroid levels (which can influence reproductive function) and yolk steroid levels (which can influence embryonic development) in oviparous species. Therefore, we examined the extent to which T and E2 are coupled in plasma and yolking follicles in adult females and explored the dynamics of yolk and embryo steroid content during egg incubation in green anoles (Anolis carolinensis). T and E2 levels were determined for the plasma and yolking follicles of breeding females and for whole embryos and yolks at several developmental stages by radioimmunoassay. Plasma and yolk concentrations of T and E2 were not correlated. On average, plasma T was only 30% that of plasma E2, but yolking follicle T was over 600% that of yolking follicle E2. Total yolk T and E2 content generally declined over the course of incubation. However, yolk T was an order of magnitude higher than yolk E2, and it showed a secondary peak in magnitude after approximately 75% of incubation was completed. Similarly, total embryonic T content rose by over 400% in the latter half of incubation whereas E2 did not change. These results demonstrate that plasma and yolking follicle steroid levels produced by breeding females can be uncoupled. Furthermore, embryos themselves may begin producing T, but likely not E2, during the latter stages of incubation. Thus, steroid exposure may be independently shaped by selection to serve both reproductive and developmental functions.
journal_name
Gen Comp Endocrinoljournal_title
General and comparative endocrinologyauthors
Lovern MB,Wade Jdoi
10.1016/s0016-6480(03)00240-5keywords:
subject
Has Abstractpub_date
2003-11-01 00:00:00pages
109-15issue
2eissn
0016-6480issn
1095-6840pii
S0016648003002405journal_volume
134pub_type
杂志文章abstract::In in vivo experiments injection of dopamine (DA) or leucine enkephalin (L-Enk) produced hypoglycemia in intact red swamp crayfish, Procambarus clarkii. In contrast, neither compound had a significant effect on the circulating glucose concentration in eyestalkless individuals. With intact crayfish spiperone, a DA rece...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1995.1015
更新日期:1995-01-01 00:00:00
abstract::A number of potential stressors are present in captive environments and it is critically important to identify them in order to improve health and welfare in ex situ animal populations. In this study, we investigated the adrenocortical activity of a colony of African penguins hosted in an immersive zoo in Italy, with ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2015.12.002
更新日期:2017-02-01 00:00:00
abstract::Enriched environmental condition (EC) has been known to reduce anxiety. In this study, we examined whether an EC could enhance anxiolytic behavior in the Indian field mouse Mus booduga by down-regulating the expression of glucocorticoid receptor (GR) through microRNA-124a. Wild individuals were captured at agricultura...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2014.01.005
更新日期:2014-04-01 00:00:00
abstract::How nestling birds respond to stressful situations may constitute an important survival component that has lasting developmental effects on the hypothalamic pituitary adrenal (HPA) axis. As birds are exposed to increasing amounts of potential anthropogenic stressors through land use change, understanding how these fac...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2011.05.010
更新日期:2011-08-01 00:00:00
abstract::Potamopyrgus antipodarum is a promising test organism that is often used in ecotoxicology, both in laboratory and field exposures. As no data are available on the physiological variation range of its life-traits and the biomarkers it uses, we studied the variation of fecundity, steroid levels and energy reserves over ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2011.03.011
更新日期:2011-06-01 00:00:00
abstract::The distribution and properties of nonapeptide binding sites in the kidney of the anuran Xenopus laevis were investigated using quantitative in vitro autoradiography. The binding studies were performed with [3H]arginine vasopressin (AVP) as ligand because [125I]arginine vasotocin (AVT) lacks biological activity. Speci...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(92)90173-h
更新日期:1992-01-01 00:00:00
abstract::Glucocorticoid hormones (GCs) are central mediators of metabolism and the response to challenges. Because circulating GC levels increase in response to challenges, within-population variation in GCs could reflect among-individual variation in condition or experience. At the same time, individual variation in GC regula...
journal_title:General and comparative endocrinology
pub_type: 杂志文章,评审
doi:10.1016/j.ygcen.2020.113611
更新日期:2021-01-01 00:00:00
abstract::The differential impact of stress on brain functions of males and females has been widely observed in vertebrates. Recent evidence suggests that stress-induced glucocorticoid signaling affects sexual differentiation and sex changes in teleost fish. These facts led us to postulate that there were sex differences in glu...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2015.09.031
更新日期:2015-11-01 00:00:00
abstract::The Harderian gland of the lizard Podarcis sicula sicula (Raf) contains connective tissue type mast cells whose numbers vary during the year showing two peaks, one in spring the other in winter. No sex differences are found throughout the year. Thermal and photoperiodic manipulations indicate that only temperature inf...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1997.6925
更新日期:1997-09-01 00:00:00
abstract::Insulin and IGF-I binding has been studied in brown trout (Salmo trutta) wheat germ agglutinin semipurified receptors from embryos (organogenesis), larvae (yolk sac), juveniles (2.98 +/- 0.21 g bw) and adults (111.6 +/- 6.92 and 522 +/- 53 g bw). Embryos and larvae were sampled at 5 and 12 weeks after fertilization (D...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.2001.7621
更新日期:2001-05-01 00:00:00
abstract::An androgen-binding activity has been identified in nuclear extracts of the testis of the frog, Rana esculenta. A single class of high affinity (Kd = 2.5 +/- 0.6 x 10(-9) M), low-capacity binding sites was found. The binding was specific for androgens; 17 beta-estradiol displaced [3H]testosterone with an ID50 of 0.1 m...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(92)90228-c
更新日期:1992-12-01 00:00:00
abstract::The courtship behavior of the male ring dove (Streptopelia risoria) combines aggressive displays (chasing, bowing) and nest-oriented displays (nest soliciting). Aggressive displays depend on circulating testosterone, whereas nest soliciting is estrogen-dependent and appears to depend on the aromatization of androgen i...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.2001.7608
更新日期:2001-04-01 00:00:00
abstract::Early maternal effects in the form of substances accumulated in the egg, such as carotenoids and hormones, can be physiologically relevant for a good development of offspring. It has been found in different species that testosterone (T) can be beneficial to offspring by increasing growth rate, but detrimental by reduc...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2007.12.010
更新日期:2008-04-01 00:00:00
abstract::Melanin-concentrating hormone (MCH) mainly regulates feeding in mammals and pigmentation in teleosts. It acts via two G-protein-coupled receptors, MCH receptor 1 (MCHR1) and MCHR2. Although many studies exploring the MCH system in teleosts and mammals have been carried out, studies on other organisms are limited. In t...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2014.03.005
更新日期:2015-02-01 00:00:00
abstract::Molting enables growth and development across ecdysozoa. The molting process is strictly controlled by hormones - ecdysteroids. Ecdysteroidogenesis occurs in theprothoracic glands and stimulated by prothoracicotropic hormone in insects, while it ensues in the Y-organ and regulated by the molt inhibiting hormone in cru...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2020.113556
更新日期:2020-11-01 00:00:00
abstract::In insects, especially phytophagous insects, feeding behavior occurs at a regular frequency. Although a number of physiological studies have revealed various causal factors leading to feeding behavior in insects, little has been demonstrated regarding the regulatory mechanisms underlying insect feeding behavior. To co...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2011.03.004
更新日期:2011-05-15 00:00:00
abstract::To study the effects of glucocorticoids and IGF-I on the modulation of growth in the tilapia Oreochromis mossambicus, we employed an epiceratobranchial cartilage radioisotope incorporation assay, wherein radiolabeled sulfate and thymidine uptakes are measured in vitro to indicate proteoglycan synthesis and cell prolif...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.2000.7599
更新日期:2001-03-01 00:00:00
abstract::Two peptides with sequence similarities to growth hormone releasing hormone (GHRH) have been identified by analysis of the chicken genome. One of these peptides, chicken (c) GHRH-LP (like peptide) was previously found to poorly bind to chicken pituitary membranes or to cloned and expressed chicken GHRH receptors and h...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2014.06.007
更新日期:2014-08-01 00:00:00
abstract::Although asymmetric development of the ovary and the oviduct is a unique characteristic in birds, the mechanism of asymmetric development still remains unclear. Recently, degradation of extracellular matrix has been suggested as an important factor related to the regression of the Müllerian duct in mammals. The presen...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2004.08.003
更新日期:2004-11-01 00:00:00
abstract::Acid extracts of neurointermediate lobe (NIL) and pars distalis (PD) of the pituitary gland of the rainbow trout were radioimmunoassayed for alpha-melanocyte-stimulating hormone (alpha-MSH), beta-melanocyte-stimulating hormone (beta-MSH), adrenocorticotrophin (ACTH), and endorphin. The majority of the alpha-MSH, beta-...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(83)90062-x
更新日期:1983-09-01 00:00:00
abstract::Insulin-like peptides (ILPs) regulate numerous functions in insects including growth, development, carbohydrate metabolism and female reproduction. This paper reports the immunohistochemical localization of ILPs in brain neurons of Rhodnius prolixus and their intimate associations with the brain circadian clock system...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2012.08.018
更新日期:2012-11-01 00:00:00
abstract::An in vitro investigation has clarified the neuroendocrine mechanism responsible for the differentiation of the female gonad in the protandrous hermaphrodite Crepidula fornicata. The male gonads were used as target organs; in some experiments they were brought to a uniform resting state by prior decerebration of donor...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(87)90129-8
更新日期:1987-03-01 00:00:00
abstract::Pancreatic polypeptide (PP) has been isolated from pancreatic extracts of the herring gull (Larus argentatus) using a radioimmunoassay employing an antiserum (PP 221), generated to the conserved C-terminal hexapeptide amide of mammalian PP. Gel permeation and reverse-phase HPLC fractionation of crude pancreatic extrac...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1994.1029
更新日期:1994-02-01 00:00:00
abstract::During metamorphosis, the tadpole neuroendocrine brain is a major target for the organisational effects of hormones acting via both endocrine feedback mechanisms and local hormone production. While the receptor-mediated actions of thyroid hormones in brain development have been well described, there is evidence that t...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2007.02.011
更新日期:2007-10-01 00:00:00
abstract::Application of alpha-MSH immunohistochemistry to the brain of elasmobranchs (Scyliorhinus torazame and Etmopterus brachyurus) demonstrated a marked species difference concerning the distribution of the alpha-MSH-like molecule in the brain. In S. torazame, alpha-MSH-like immunoreactive cells were present in the hypotha...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.2001.7628
更新日期:2001-06-01 00:00:00
abstract::In dairy cows, heat stress depresses appetite, leading to decreased food intake, a negative energy balance, and modifies ghrelin levels. Ghrelin is a gut-brain peptide with two major forms: acylated, with an O-n-octanoylated serine in position 3, and nonacylated. To date, the effect of heat stress and estrous cycle on...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2016.06.006
更新日期:2016-09-01 00:00:00
abstract::There are more CRH-like immunoreactive neurons in the preoptic nucleus and nucleus lateralis tuberis in the brain of feral brown trout, Salmo trutta, living in cadmium- and zinc-contaminated regions of the Eagle River than in fish from an uncontaminated control site. Histological analyses revealed that interrenal cell...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1997.7000
更新日期:1997-12-01 00:00:00
abstract::In anaesthetized young (6 weeks old) and adult (22-30 weeks old) domestic fowl, the administration of thyrotrophin releasing hormone (TRH; 1.0 micrograms/kg in young birds; 10.0 micrograms/kg in adults) or human pancreatic growth hormone-releasing factor (hpGRF(1-44)NH2; 10.0 micrograms/kg in both cases) markedly incr...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(85)90413-7
更新日期:1985-07-01 00:00:00
abstract::Many vertebrates have more than one molecular form of gonadotropin-releasing hormone (GnRH) present in brain. In all cases documented to date, GnRH neurons located in the forebrain are critical players in the brain-pituitary-gonadal feedback axis although the details of how steroids regulate GnRH remain elusive. The f...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1998.7135
更新日期:1998-12-01 00:00:00
abstract::Wrasse species exhibit a definite daily rhythm in locomotor activity and bury themselves in the sand at the bottom of the ocean at night. It remains unclear how their behavior in locomotor activity is endogenously regulated. The aim of the present study was to clarify the involvement of melatonin and clock genes (Per1...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2012.01.007
更新日期:2012-05-15 00:00:00