scholarly journals Gonads or body? Differences in gonadal and somatic photoperiodic growth response in two vole species

2020 ◽  
Vol 223 (20) ◽  
pp. jeb230987
Author(s):  
Laura van Rosmalen ◽  
Jayme van Dalum ◽  
David G. Hazlerigg ◽  
Roelof A. Hut

ABSTRACTTo optimally time reproduction, seasonal mammals use a photoperiodic neuroendocrine system (PNES) that measures photoperiod and subsequently drives reproduction. To adapt to late spring arrival at northern latitudes, a lower photoperiodic sensitivity and therefore a higher critical photoperiod for reproductive onset is necessary in northern species to arrest reproductive development until spring onset. Temperature–photoperiod relationships, and hence food availability–photoperiod relationships, are highly latitude dependent. Therefore, we predict PNES sensitivity characteristics to be latitude dependent. Here, we investigated photoperiodic responses at different times during development in northern (tundra or root vole, Microtus oeconomus) and southern vole species (common vole, Microtus arvalis) exposed to constant short (SP) or long photoperiod (LP). Although the tundra vole grows faster under LP, no photoperiodic effect on somatic growth is observed in the common vole. In contrast, gonadal growth is more sensitive to photoperiod in the common vole, suggesting that photoperiodic responses in somatic and gonadal growth can be plastic, and might be regulated through different mechanisms. In both species, thyroid-stimulating hormone β-subunit (Tshβ) and iodothyronine deiodinase 2 (Dio2) expression is highly increased under LP, whereas Tshr and Dio3 decrease under LP. High Tshr levels in voles raised under SP may lead to increased sensitivity to increasing photoperiods later in life. The higher photoperiodic-induced Tshr response in tundra voles suggests that the northern vole species might be more sensitive to thyroid-stimulating hormone when raised under SP. In conclusion, species differences in developmental programming of the PNES, which is dependent on photoperiod early in development, may form different breeding strategies as part of latitudinal adaptation.

2020 ◽  
Author(s):  
Laura van Rosmalen ◽  
Jayme van Dalum ◽  
David G. Hazlerigg ◽  
Roelof A. Hut

AbstractTo optimally time reproduction, seasonal mammals use a photoperiodic neuroendocrine system (PNES) that measures photoperiod and subsequently drives reproduction. To adapt to late spring arrival at northern latitudes, a lower photoperiodic sensitivity and therefore a higher critical photoperiod for reproductive onset is necessary in northern species to arrest reproductive development until spring onset. Temperature-photoperiod relationships, and hence food availability-photoperiod relationships, are highly latitude dependent. Therefore, we predict PNES sensitivity characteristics to be latitude-dependent. Here, we investigated photoperiodic responses at different times during development in northern- (tundra/root vole, Microtus oeconomus) and southern vole species (common vole, Microtus arvalis) exposed to constant short (SP) or long photoperiod (LP).M. oeconomus grows faster under LP, whereas no photoperiodic effect on somatic growth is observed in M. arvalis. Contrastingly, gonadal growth is more sensitive to photoperiod in M. arvalis, suggesting that photoperiodic responses in somatic and gonadal growth can be plastic, and might be regulated through different mechanisms. In both species, thyroid-stimulating-hormone-β subunit (Tshβ) and iodothyronine-deiodinase 2 (Dio2) expression is highly increased under LP, whereas Tshr and Dio3 decreases under LP. High Tshr levels in voles raised under SP may lead to increased sensitivity to increasing photoperiods later in life. The higher photoperiodic induced Tshr response in M. oeconomus suggests that the northern vole species might be more sensitive to TSH when raised under SP.Species differences in developmental programming of the PNES, which is dependent on photoperiod early in development, may form part divergent breeding strategies evolving as part of latitudinal adaptation.Summary statementDevelopment of the neuroendocrine system driving photoperiodic responses in gonadal and somatic growth differ between the common and the tundra vole, indicating that they use a different breeding strategy.


2002 ◽  
Vol 48 (11) ◽  
pp. 2023-2029 ◽  
Author(s):  
Adel AA Ismail ◽  
Paul L Walker ◽  
Julian H Barth ◽  
Kryzsztof C Lewandowski ◽  
Rick Jones ◽  
...  

Abstract Background: Immunoassays are used in almost all medical and surgical specialties, but they suffer from interference from proteins such as antibodies in some patients’ sera. Such interferences are usually reported in the literature only as case reports after the introduction of a new assay. Methods: We undertook a prospective observational study on 5310 patients for whom the common immunoassay tests for thyroid-stimulating hormone (TSH) and/or gonadotropins were requested. All TSH and gonadotropin results were critically assessed for a mismatch between the clinical details and analytical results to identify samples suspected of analytical unreliability. These were tested further by three approaches to screen for interference. Results: From the 5310 sets of results, 59 patients’ samples were identified as suspect and were tested further. Analytically incorrect results were found in 28 (0.53% of the total studied). The magnitude of interference varied, but in 23 of 28 patients (82%), it was considered large enough to have a potentially adverse effect on cost and/or the clinical care of these patients. Two cases, described in detail, illustrate the adverse effect of error on patient care and cost, and the second highlights the difficulties and limitations of current approaches for identifying interference and inaccuracy in immunoassays. Conclusions: Because millions of TSH/gonadotropin tests are carried out in UK hospital laboratories alone, our data suggest that thousands of patients could be adversely affected by errors from interferences. Early identification of interference in cases with unusual results could be valuable.


2016 ◽  
Vol 231 (3) ◽  
pp. 197-207 ◽  
Author(s):  
Iulia Potorac ◽  
Adolfo Rivero-Müller ◽  
Ashutosh Trehan ◽  
Michał Kiełbus ◽  
Krzysztof Jozwiak ◽  
...  

Glycoprotein hormones are complex hormonally active macromolecules. Luteinizing hormone (LH) is essential for the postnatal development and maturation of the male gonad. Inactivating Luteinizing hormone beta (LHB) gene mutations are exceptionally rare and lead to hypogonadism that is particularly severe in males. We describe a family with selective LH deficiency and hypogonadism in two brothers. DNA sequencing of LHB was performed and the effects of genetic variants on hormone function and secretion were characterized by mutagenesis studies, confocal microscopy and functional assays. A 20-year-old male from a consanguineous family had pubertal delay, hypogonadism and undetectable LH. A homozygous c.118_120del (p.Lys40del) mutation was identified in the patient and his brother, who subsequently had the same phenotype. Treatment with hCG led to pubertal development, increased circulating testosterone and spermatogenesis. Experiments in HeLa cells revealed that the mutant LH is retained intracellularly and showed diffuse cytoplasmic distribution. The mutated LHB heterodimerizes with the common alpha-subunit and can activate its receptor. Deletion of flanking glutamic acid residues at positions 39 and 41 impair LH to a similar extent as deletion of Lys40. This region is functionally important across all heterodimeric glycoprotein hormones, because deletion of the corresponding residues in hCG, follicle-stimulating hormone and thyroid-stimulating hormone beta-subunits also led to intracellular hormone retention. This novel LHB mutation results in hypogonadism due to intracellular sequestration of the hormone and reveals a discrete region in the protein that is crucial for normal secretion of all human glycoprotein hormones.


2018 ◽  
Vol 60 (3) ◽  
pp. R131-R155 ◽  
Author(s):  
Nandana Das ◽  
T Rajendra Kumar

Follicle-stimulating hormone (FSH) plays fundamental roles in male and female fertility. FSH is a heterodimeric glycoprotein expressed by gonadotrophs in the anterior pituitary. The hormone-specific FSHβ-subunit is non-covalently associated with the common α-subunit that is also present in the luteinizing hormone (LH), another gonadotrophic hormone secreted by gonadotrophs and thyroid-stimulating hormone (TSH) secreted by thyrotrophs. Several decades of research led to the purification, structural characterization and physiological regulation of FSH in a variety of species including humans. With the advent of molecular tools, availability of immortalized gonadotroph cell lines and genetically modified mouse models, our knowledge on molecular mechanisms of FSH regulation has tremendously expanded. Several key players that regulate FSH synthesis, sorting, secretion and action in gonads and extragonadal tissues have been identified in a physiological setting. Novel post-transcriptional and post-translational regulatory mechanisms have also been identified that provide additional layers of regulation mediating FSH homeostasis. Recombinant human FSH analogs hold promise for a variety of clinical applications, whereas blocking antibodies against FSH may prove efficacious for preventing age-dependent bone loss and adiposity. It is anticipated that several exciting new discoveries uncovering all aspects of FSH biology will soon be forthcoming.


1996 ◽  
Vol 20 (6) ◽  
pp. 354-355 ◽  
Author(s):  
Carol Paton ◽  
Dominic Beer

The common thyroid disorders are all autoimmune in origin, with the lifetime risk of thyroid disease being 1–2%. Thyroid autoantibodies are present in 9% of the adult population and 12.7% of women, with the frequency rising steeply in women over 45 years of age (Myers & West, 1987). In addition, 20% of the over 60–year-olds have an abnormal (raised) thyroid stimulating hormone (TSH). The presence of both raised TSH and thyroid autoantibodies is associated with the development of clinical hypothyroidism at the rate of 5% per year (Myers & West, 1987).


1961 ◽  
Vol 38 (4) ◽  
pp. 577-584 ◽  
Author(s):  
Sven Erik Björkman ◽  
Torsten Denneberg ◽  
Inge Hedenskog

ABSTRACT A method for demonstrating the presence of a thyroid stimulating factor in the blood of patients with progressive exophthalmos after thyroidectomy or after treatment with radioiodine is described. The method consists of transfusing freshly drawn blood from the patients to euthyroid recipients and subsequently following the PBI level of the recipients at regular intervals. Six exophthalmic patients tested in this manner were found to have such a factor in their circulating blood. After transfusion of their blood a significant rise in the PBI level of the recipients could be demonstrated. Two other patients, one with exophthalmos of long duration did not show this response nor did it occur after transfusion of blood from two control subjects. In one case the action of this factor was compared with that of animal thyrotrophin and found to be of the same magnitude.


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