scholarly journals Hybridization with mountain hares increases the functional allelic repertoire in brown hares

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jaakko L. O. Pohjoismäki ◽  
Craig Michell ◽  
Riikka Levänen ◽  
Steve Smith
Keyword(s):  
Gene Flow ◽  
Native Species ◽  
Balancing Selection ◽  
Uncoupling Protein ◽  
Lepus Europaeus ◽  
Genetic Introgression ◽  
Mountain Hare ◽  
Uncoupling Protein 1 ◽  
Allelic Variability ◽  
Candidate Loci

AbstractBrown hares (Lepus europaeus Pallas) are able to hybridize with mountain hares (L. timidus Linnaeus) and produce fertile offspring, which results in cross-species gene flow. However, not much is known about the functional significance of this genetic introgression. Using targeted sequencing of candidate loci combined with mtDNA genotyping, we found the ancestral genetic diversity in the Finnish brown hare to be small, likely due to founder effect and range expansion, while gene flow from mountain hares constitutes an important source of functional genetic variability. Some of this variability, such as the alleles of the mountain hare thermogenin (uncoupling protein 1, UCP1), might have adaptive advantage for brown hares, whereas immunity-related MHC alleles are reciprocally exchanged and maintained via balancing selection. Our study offers a rare example where an expanding species can increase its allelic variability through hybridization with a congeneric native species, offering a route to shortcut evolutionary adaptation to the local environmental conditions.

scholarly journals The best of both worlds: Shortcutting evolution through adaptive hybridization in hares

2021 ◽  
Author(s):  
Jaakko L.O. Pohjoismäki ◽  
Craig Michell ◽  
Riikka Levänen ◽  
Steve Smith
Keyword(s):  
Gene Flow ◽  
Balancing Selection ◽  
Uncoupling Protein ◽  
Lepus Europaeus ◽  
Genetic Introgression ◽  
The Novel ◽  
Mountain Hare ◽  
Uncoupling Protein 1 ◽  
Expansion Load ◽  
Candidate Loci

Abstract Brown hares (Lepus europaeus Pallas) are able to hybridize with mountain hares (L. timidus Linnaeus) and produce fertile offspring, which results in cross-species gene flow. However, not much is known about the functional significance of this genetic introgression. Using targeted sequencing of candidate loci combined with mtDNA genotyping, we found the ancestral genetic diversity in the brown hare to be small, likely due to founder effect and range expansion, while gene flow from mountain hares constitutes an important source of functional genetic variability. Some of this variability, such as the alleles of the mountain hare thermogenin (uncoupling protein 1, UCP1), is likely of adaptive advantage for brown hares, whereas immunity-related MHC alleles are reciprocally exchanged and maintained via balancing selection. Our study offers a rare example where an expanding species can ease its expansion load through hybridization and obtain beneficial alleles to shortcut evolutionary adaptation to the novel environmental conditions.

Evidence of Browning of White Adipocytes in Poorly Survived Fat Grafts in Patients

2021 ◽  
Author(s):  
Tong Liu ◽  
Su Fu ◽  
Qian Wang ◽  
Hao Cheng ◽  
Dali Mu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Uncoupling Protein ◽  
Fold Increase ◽  
Fat Grafting ◽  
Electronic Microscopy ◽  
Uncoupling Protein 1 ◽  
Fat Transfer ◽  
Flap Transfer ◽  
Fat Grafts ◽  
White Adipocytes

Abstract Background Browning adipocytes induced by burn and cancer were assumed less viable and more prone to necrosis for their hypermetabolic properties. Recent studies have shown browning of white adipose after fat engraftment in mice. Objectives We tend to evaluate whether fat transfer could induce browning biogenesis in fat grafts in humans and if it is associated with graft necrosis. Methods Necrotic adipose grafts were excised from 11 patients diagnosed with fat necrosis after fat grafting or flap transfer. Non-necrotic fat grafts were from 5 patients undergoing revisionary surgeries after flap transfer. Histology and electronic microscopy, protein and gene expression of browning related marker analyses were performed. Results Fat grafts with necrosis demonstrated a higher gene expression level of uncoupling protein-1 (>5-fold increase, **p<0.01), a master beige adipocyte marker, than non-necrotic fat grafts. Electronic microscopy and histology showed that browning adipocytes were presented in necrotic adipose in patients. Conclusions Fat transfer induced browning adipocytes in patients and was evident in patients with post grafting necrosis.

Growth factor regulation of uncoupling protein-1 mRNA expression in brown adipocytes

2002 ◽  
Vol 282 (1) ◽  
pp. C105-C112 ◽  
Author(s):  
Bibian García ◽  
Maria-Jesús Obregón
Keyword(s):  
Growth Factor ◽  
Adipocyte Differentiation ◽  
Uncoupling Protein ◽  
Brown Adipocyte ◽  
Mrna Levels ◽  
Uncoupling Protein 1 ◽  
Brown Adipocytes ◽  
Proliferation And Differentiation ◽  
Epidermal Growth ◽  
Continuous Presence

To study the effect of the mitogens epidermal growth factor (EGF), acidic and basic fibroblast growth factors (aFGF and bFGF), and vasopressin on brown adipocyte differentiation, we analyzed the expression of uncoupling protein-1 (UCP-1) mRNA. Quiescent brown preadipocytes express high levels of UCP-1 mRNA in response to triiodothyronine (T3) and norepinephrine (NE). The addition of serum or the mitogenic condition aFGF + vasopressin + NE or EGF + vasopressin + NE decreases UCP-1 mRNA. A second addition of mitogens further decreases UCP-1 mRNA. Treatment with aFGF or bFGF alone increases UCP-1 mRNA, whereas the addition of EGF or vasopressin dramatically reduces UCP-1 mRNA levels. The continuous presence of T3 increases UCP-1 mRNA levels in cells treated with EGF, aFGF, or bFGF. The effect of T3 on the stimulation of DNA synthesis also was tested. T3 inhibits the mitogenic activity of aFGF and bFGF. In conclusion, mitogens like aFGF or bFGF allow brown adipocyte differentiation, whereas EGF and vasopressin inhibit the differentiation process. T3 behaves as an important hormone that regulates both brown adipocyte proliferation and differentiation.

scholarly journals The Role of Uncoupling Protein 1 in the Metabolism and Adiposity of RIIβ-Protein Kinase A-Deficient Mice

2004 ◽  
Vol 18 (9) ◽  
pp. 2302-2311 ◽  
Author(s):  
Michael A. Nolan ◽  
Maria A. Sikorski ◽  
G. Stanley McKnight
Keyword(s):  
Adipose Tissue ◽  
Oxygen Consumption ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Uncoupling Protein ◽  
Mrna Level ◽  
Regulatory Subunit ◽  
Uncoupling Protein 1 ◽  
Brown Adipose ◽  
Kinase A

Abstract Mice lacking the RIIβ regulatory subunit of protein kinase A exhibit a 50% reduction in white adipose tissue stores compared with wild-type littermates and are resistant to diet-induced obesity. RIIβ−/− mice also have an increase in resting oxygen consumption along with a 4-fold increase in the brown adipose-specific mitochondrial uncoupling protein 1 (UCP1). In this study, we examined the basis for UCP1 induction and tested the hypothesis that the induced levels of UCP1 in RIIβ null mice are essential for the lean phenotype. The induction of UCP1 occurred at the protein but not the mRNA level and correlated with an increase in mitochondria in brown adipose tissue. Mice lacking both RIIβ and UCP1 (RIIβ−/−/Ucp1−/−) were created, and the key parameters of metabolism and body composition were studied. We discovered that RIIβ−/− mice exhibit nocturnal hyperactivity in addition to the increased oxygen consumption at rest. Disruption of UCP1 in RIIβ−/− mice reduced basal oxygen consumption but did not prevent the nocturnal hyperactivity. The double knockout animals also retained the lean phenotype of the RIIβ null mice, demonstrating that induction of UCP1 and increased resting oxygen consumption is not the cause of leanness in the RIIβ mutant mice.

Immunodetection of UCP1 in rat thymocytes

2004 ◽  
Vol 32 (6) ◽  
pp. 1066-1067 ◽  
Author(s):  
A.M. Carroll ◽  
L.R. Haines ◽  
T.W. Pearson ◽  
C. Brennan ◽  
E.P. Breen ◽  
...  
Keyword(s):  
Connective Tissue ◽  
Uncoupling Protein ◽  
Immunoblot Analysis ◽  
Uncoupling Protein 1

Thymi were dissected from rats and connective tissue was removed. Mitochondria were purified from isolated thymocytes and immunoblot analysis was performed using an antibody specific for uncoupling protein 1, which detected a 32.5 kDa protein associated with mitochondria from the thymocytes. This implies that rat thymocytes contain uncoupling protein 1.

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