Sexually dimorphic response on bone development after neonatal thymectomy in rats

2016 ◽  
Author(s):  
Mello Wagner Garcez de ◽  
Noelle Egidia Watanabe Kiill ◽  
Gisele Mitsui Kayahara ◽  
Olivia Borghi Nascimento ◽  
Narayana Guimaraes Marqui ◽  
...  
Author(s):  
Darcy B. Kelley ◽  
Martha L. Tobias ◽  
Mark Ellisman

Brain and muscle are sexually differentiated tissues in which masculinization is controlled by the secretion of androgens from the testes. Sensitivity to androgen is conferred by the expression of an intracellular protein, the androgen receptor. A central problem of sexual differentiation is thus to understand the cellular and molecular basis of androgen action. We do not understand how hormone occupancy of a receptor translates into an alteration in the developmental program of the target cell. Our studies on sexual differentiation of brain and muscle in Xenopus laevis are designed to explore the molecular basis of androgen induced sexual differentiation by examining how this hormone controls the masculinization of brain and muscle targets.Our approach to this problem has focused on a highly androgen sensitive, sexually dimorphic neuromuscular system: laryngeal muscles and motor neurons of the clawed frog, Xenopus laevis. We have been studying sex differences at a synapse, the laryngeal neuromuscular junction, which mediates sexually dimorphic vocal behavior in Xenopus laevis frogs.


2007 ◽  
Vol 28 (2) ◽  
pp. 78-87 ◽  
Author(s):  
Stefan J. Troche ◽  
Nina Weber ◽  
Karina Hennigs ◽  
Carl-René Andresen ◽  
Thomas H. Rammsayer

Abstract. The ratio of second to fourth finger length (2D:4D ratio) is sexually dimorphic with women having higher 2D:4D ratio than men. Recent studies on the relationship between 2D:4D ratio and gender-role orientation yielded rather inconsistent results. The present study examines the moderating influence of nationality on the relationship between 2D:4D ratio and gender-role orientation, as assessed with the Bem Sex-Role Inventory, as a possible explanation for these inconsistencies. Participants were 176 female and 171 male university students from Germany, Italy, Spain, and Sweden ranging in age from 19 to 32 years. Left-hand 2D:4D ratio was significantly lower in men than in women across all nationalities. Right-hand 2D:4D ratio differed only between Swedish males and females indicating that nationality might effectively moderate the sexual dimorphism of 2D:4D ratio. In none of the examined nationalities was a reliable relationship between 2D:4D ratio and gender-role orientation obtained. Thus, the assumption of nationality-related between-population differences does not seem to account for the inconsistent results on the relationship between 2D:4D ratio and gender-role orientation.


2020 ◽  
Vol 134 (4) ◽  
pp. 309-322 ◽  
Author(s):  
Tristan J. Hynes ◽  
Jacqueline-Marie M. Ferland ◽  
Tanya L. Feng ◽  
Wendy K. Adams ◽  
Mason M. Silveira ◽  
...  

2020 ◽  
Vol 139 ◽  
pp. 93-102 ◽  
Author(s):  
MF Van Bressem ◽  
P Duignan ◽  
JA Raga ◽  
K Van Waerebeek ◽  
N Fraijia-Fernández ◽  
...  

Crassicauda spp. (Nematoda) infest the cranial sinuses of several odontocetes, causing diagnostic trabecular osteolytic lesions. We examined skulls of 77 Indian Ocean humpback dolphins Sousa plumbea and 69 Indo-Pacific bottlenose dolphins Tursiops aduncus, caught in bather-protecting nets off KwaZulu-Natal (KZN) from 1970-2017, and skulls of 6 S. plumbea stranded along the southern Cape coast in South Africa from 1963-2002. Prevalence of cranial crassicaudiasis was evaluated according to sex and cranial maturity. Overall, prevalence in S. plumbea and T. aduncus taken off KZN was 13 and 31.9%, respectively. Parasitosis variably affected 1 or more cranial bones (frontal, pterygoid, maxillary and sphenoid). No significant difference was found by gender for either species, allowing sexes to be pooled. However, there was a significant difference in lesion prevalence by age, with immature T. aduncus 4.6 times more likely affected than adults, while for S. plumbea, the difference was 6.5-fold. As severe osteolytic lesions are unlikely to heal without trace, we propose that infection is more likely to have a fatal outcome for immature dolphins, possibly because of incomplete bone development, lower immune competence in clearing parasites or an over-exuberant inflammatory response in concert with parasitic enzymatic erosion. Cranial osteolysis was not observed in mature males (18 S. plumbea, 21 T. aduncus), suggesting potential cohort-linked immune-mediated resistance to infestation. Crassicauda spp. may play a role in the natural mortality of S. plumbea and T. aduncus, but the pathogenesis and population level impact remain unknown.


Author(s):  
Dumontet T ◽  
Sahut-Barnola I ◽  
Septier A ◽  
Montanier N ◽  
Plotton I ◽  
...  

2016 ◽  
Vol 6 (1) ◽  
pp. 846-852
Author(s):  
Olugbenga Adeniran Ogunwole ◽  
B. C Majekodunmi ◽  
R. A Faboyede ◽  
D. Ogunsiji

Effects of supplemental dietary lysine and methionine in a Groundnut Cake (GNC) based diets on meat and bone characteristics of broiler chickens were investigated. In a completely randomized design, a total of 168 one - day – old Arbor acre broiler chicks were randomly allocated to seven dietary treatments each in triplicate of eight birds per replicate. The Seven starter and finishers’ diets were: GNC based diets without any amino acid (lysine or methionine) supplementation (T1); GNC diet + 0.2% lysine (T2); GNC diet + 0.4% lysine (T3); GNC diet + 0.2% methionine (T4); GNC diet + 0.4% methionine (T5); GNC diet + 0.2 lysine and 0.2% methionine (T6) and GNC diet + 0.4% lysine and 0.4% methionine (T7). Experimental diets and water were offered to birds ad libitum in an experiment lasting six-week. At day 42, two birds per replicate were slaughtered, meat and bone characteristics determined. There were significant variations (P<0.05) in the crude protein (%) and ether extract (%), pH1 and pH2 of meat. Thiobarbituric acid reactive substances composition of meat at days 0, 5, and 10 were similar (P<0.05) and were not affected by dietary amino acid supplementation. Tibiotarsal index (mg/mm) of bone (22.10, 27.25, 33.35, 31.40, 28.70, 31.45 and 29.75 for broilers on T1, T2, T3, T4, T5, T6 and T7, respectively) were increased significantly (P<0.05) by amino acid supplementation. Significantly differences (P<0.05) were observed in the calcium, phosphorus and potassium (%) contents of broilers’ bone across treatments. Supplemental lysine and both lysine and methionine improved meat quality and bone development of broiler chickens in this study.


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