Developmental changes in the role of gonadotropin-inhibitory hormone (GnIH) and its receptors in the reproductive axis of male Xiaomeishan pigs

2015 ◽  
Vol 154 ◽  
pp. 113-120 ◽  
Author(s):  
Lucheng Zheng ◽  
Juan Su ◽  
Rui Fang ◽  
Mengmeng Jin ◽  
Zhihai Lei ◽  
...  
2017 ◽  
Vol 114 (5) ◽  
pp. 1207-1212 ◽  
Author(s):  
Diana E. Peragine ◽  
Martha Pokarowski ◽  
Lucia Mendoza-Viveros ◽  
Ashlyn Swift-Gallant ◽  
Hai-Ying M. Cheng ◽  
...  

Neuroendocrine mechanisms underlying social inhibition of puberty are not well understood. Here, we use a model exhibiting the most profound case of pubertal suppression among mammals to explore a role for RFamide-related peptide-3 [RFRP-3; mammalian ortholog to gonadotropin-inhibitory hormone (GnIH)] in neuroendocrine control of reproductive development. Naked mole rats (NMRs) live in sizable colonies where breeding is monopolized by two to four dominant animals, and no other members exhibit signs of puberty throughout their lives unless they are removed from the colony. Because of its inhibitory action on the reproductive axis in other vertebrates, we investigated the role of RFRP-3 in social reproductive suppression in NMRs. We report that RFRP-3 immunofluorescence expression patterns and RFRP-3/GnRH cross-talk are largely conserved in the NMR brain, with the exception of the unique presence of RFRP-3 cell bodies in the arcuate nucleus (Arc). Immunofluorescence comparisons revealed that central expression of RFRP-3 is altered by reproductive status, with RFRP-3 immunoreactivity enhanced in the paraventricular nucleus, dorsomedial nucleus, and Arc of reproductively quiescent NMRs. We further observed that exogenous RFRP-3 suppresses gonadal steroidogenesis and mating behavior in NMRs given the opportunity to undergo puberty. Together, our findings establish a role for RFRP-3 in preserving reproductive immaturity, and challenge the view that stimulatory peptides are the ultimate gatekeepers of puberty.


2016 ◽  
Vol 94 (6) ◽  
Author(s):  
José A. Paullada-Salmerón ◽  
Mairi Cowan ◽  
María Aliaga-Guerrero ◽  
Francesca Morano ◽  
Silvia Zanuy ◽  
...  

Abstract Gonadotropin-inhibitory hormone (GnIH) inhibits gonadotropin synthesis and release from the pituitary of birds and mammals. However, the physiological role of orthologous GnIH peptides on the reproductive axis of fish is still uncertain, and their actions on the main neuroendocrine systems controlling reproduction (i.e., GnRHs, kisspeptins) have received little attention. In a recent study performed in the European sea bass, we cloned a cDNA encoding a precursor polypeptide that contained C-terminal MPMRFamide (sbGnIH-1) and MPQRFamide (sbGnIH-2) peptide sequences, developed a specific antiserum against sbGnIH-2, and characterized its central and pituitary GnIH projections in this species. In this study, we analyzed the effects of intracerebroventricular injection of sbGnIH-1 and sbGnIH-2 on brain and pituitary expression of reproductive hormone genes (gnrh1, gnrh2, gnrh3, kiss1, kiss2, gnih, lhbeta, fshbeta), and their receptors (gnrhr II-1a, gnrhr II-2b, kiss1r, kiss2r, and gnihr) as well as on plasma Fsh and Lh levels. In addition, we determined the effects of GnIH on pituitary somatotropin (Gh) expression. The results obtained revealed the inhibitory role of sbGnIH-2 on brain gnrh2, kiss1, kiss2, kiss1r, gnih, and gnihr transcripts and on pituitary fshbeta, lhbeta, gh, and gnrhr-II-1a expression, whereas sbGnIH-1 only down-regulated brain gnrh1 expression. However, at different doses, central administration of both sbGnIH-1 and sbGnIH-2 decreased Lh plasma levels. Our work represents the first study reporting the effects of centrally administered GnIH in fish and provides evidence of the differential actions of sbGnIH-1 and sbGnIH-2 on the reproductive axis of sea bass, the main inhibitory role being exerted by the sbGnIH-2 peptide.


2003 ◽  
Vol 178 (2) ◽  
pp. 311-318 ◽  
Author(s):  
T Ubuka ◽  
M Ueno ◽  
K Ukena ◽  
K Tsutsui

We previously isolated a novel dodecapeptide containing a C-terminal -Arg-Phe-NH(2) sequence, SIKPSAYLPLRF-NH(2) (RFamide peptide), from the Japanese quail (Coturnix japonica) brain. This novel quail peptide was shown to be located in neurons of the paraventricular nucleus (PVN) and their terminals in the median eminence (ME), and to decrease gonadotropin release from cultured anterior pituitary in adult birds. We therefore designated this peptide gonadotropin-inhibitory hormone (GnIH). Furthermore, a cDNA encoding the GnIH precursor polypeptide has been characterized. To understand the physiological roles of this peptide, in the present study we analyzed developmental changes in the expressions of GnIH precursor mRNA and the mature peptide GnIH during embryonic and posthatch ages in the quail diencephalon including the PVN and ME. GnIH precursor mRNA was expressed in the diencephalon on embryonic day 10 (E10) and showed a significant increase on E17, just before hatch. GnIH was also detected in the diencephalon on E10 and increased significantly around hatch. Subsequently, the diencephalic GnIH content decreased temporarily, and again increased progressively until adulthood. GnIH-like immunoreactive (GnIH-ir) neurons were localized in the PVN on E10, but GnIH-ir fibers did not extend to the ME. However, GnIH-ir neurons increased in the PVN on E17, just before hatch, and GnIH-ir fibers extended to the external layer of the ME, as in adulthood. These results suggest that GnIH begins its function around hatch and acts as a hypothalamic factor to regulate gonadotropin release in the bird.


2015 ◽  
Vol 233 (2) ◽  
pp. 138-147 ◽  
Author(s):  
S. López-Doval ◽  
R. Salgado ◽  
B. Fernández-Pérez ◽  
A. Lafuente

2018 ◽  
Vol 115 (47) ◽  
pp. 11941-11946 ◽  
Author(s):  
Erik Trinkaus

Diverse developmental abnormalities and anomalous features are evident in the PleistoceneHomofossil record, varying from minor but rare dental, vertebral, and carpal variants to exceptional systemic disorders. There are currently 75 documented anomalies or abnormalities from 66 individuals, spanning the Pleistocene but primarily from the Late Pleistocene Middle and Upper Paleolithic with their more complete skeletal remains. The expected probabilities of finding these variants or developmental disorders vary from <5% to <0.0001%, based on either recent human incidences or relevant Pleistocene sample distributions. Given the modest sample sizes available for the skeletal or dental elements in question, especially if the samples are appropriately limited in time and geography, the cumulative multiplicative probability of finding these developmental changes is vanishingly small. These data raise questions regarding social survival abilities, differing mortuary treatments of the biologically unusual, the role of ubiquitous stress among these Pleistocene foragers, and their levels of consanguinity. No single factor sufficiently accounts for the elevated level of these developmental variants or the low probability of finding them in the available paleontological record.


2009 ◽  
Vol 2009 ◽  
pp. 1-6 ◽  
Author(s):  
David Talavera ◽  
Modesto Orozco ◽  
Xavier de la Cruz

Functional modification of transcription regulators may lead to developmental changes and phenotypical differences between species. In this work, we study the influence of alternative splicing on transcription factors in human and mouse. Our results show that the impact of alternative splicing on transcription factors is similar in both species, meaning that the ways to increase variability should also be similar. However, when looking at the expression patterns of transcription factors, we observe that they tend to diverge regardless of the role of alternative splicing. Finally, we hypothesise that transcription regulation of alternatively spliced transcription factors could play an important role in the phenotypical differences between species, without discarding other phenomena or functional families.


2018 ◽  
Vol 66 (5) ◽  
pp. 379 ◽  
Author(s):  
Igor Ballego-Campos ◽  
Elder Antônio Sousa Paiva

Colleters are common among eudicotyledons, but few records exist for monocotyledons and other groups of plants. For Bromeliaceae, mucilage secretions that protect the young portions of the plant have been observed only in the reproductive axis, and little is known about the secretory systems behind this or even other kind of secretions in the family. We aimed to describe, for the first time, the occurrence of colleters associated with the vegetative shoot of Aechmea blanchetiana (Baker) L.B.Sm., and elucidate aspects of their structure, ultrastructure and secretory activity. Samples of various portions of the stem axis were prepared according to standard methods for light and electron microscopy. Colleters were found compressed in the axillary portion of leaves and in all leaf developmental stages. Secretory activity, however, was found to be restricted to young and unexpanded leaves. The colleters displayed a flattened hand-like shape formed by a multiseriate stalk and an expanded secretory portion bearing elongated marginal cells. Ultrastructural data confirmed that the secretory role of the colleters is consistent with mucilaginous secretion. The functional roles of the colleters are discussed with regard to environmental context and intrinsic features of the plant, such as the presence of a water-impounding tank.


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