Temperature-dependent sex determination（TSD） is a type of environmental sex determination in which the sex of the embryos depends on the ambient temperature; however,the molecular mechanisms governing this process r...Temperature-dependent sex determination（TSD） is a type of environmental sex determination in which the sex of the embryos depends on the ambient temperature; however,the molecular mechanisms governing this process remain unknown.Aromatase,encoded by the cyp19a1 gene,which converts androgens into estrogens in animals,was considered to be the key gene for TSD.In this study,the 5＇-flanking region of the cyp19a1 gene in Reeves＇ turtle（Mauremys reevesii） was cloned,and the promoter region was identified using the luciferase reporter assay.Then the eggs of Reeves＇ turtle were incubated at different temperatures（26°C： male-biased temperature; 29°C： non-sex-biased temperature and 32°C： female-biased temperature）.During the thermosensitive period,the adrenal kidney gonad complexes（AKG） were sampled.DNA methylation analysis of the AKG samples showed that the promoter region of the cyp19a1 gene was significantly de-methylated in the female-biased temperature regime（P＆lt;0.01）.Quantitative analysis of the cyp19a1 gene and estrogen by q PCR and Elisa assay showed that the expression level of the cyp19a1 gene and estrogen content were both upregulated significantly at the female-biased temperature（P＆lt;0.01）.These results indicated that the de-methylation response of the cyp19a1 gene to incubation temperature,especially at the female-biased temperature,could lead to temperature-specific expression of aromatase and increased estrogen levels,which may further determine gonadal development in Reeves＇ turtle.These findings provide insights into the genetic mechanisms underlying TSD.展开更多
背景:难复性股骨转子间骨折往往无法通过牵引床牵引得到良好的复位,需要切开或者应用其他微创复位技术进行辅助复位。目的:探讨侧卧位牵引复位股骨近端防旋髓内钉固定对难复性股骨转子间骨折的复位效果。方法:回顾性分析2013年5月至2015...背景:难复性股骨转子间骨折往往无法通过牵引床牵引得到良好的复位,需要切开或者应用其他微创复位技术进行辅助复位。目的:探讨侧卧位牵引复位股骨近端防旋髓内钉固定对难复性股骨转子间骨折的复位效果。方法:回顾性分析2013年5月至2015年8月收治的84例难复性股骨转子间骨折患者的资料,均为新鲜骨折,骨折按AO分型:A2型26例,A3型58例。根据骨折复位方法的不同,分为侧卧位手法牵引复位组(A组)和平卧位牵引床牵引复位组(B组),每组42例。分析比较2组患者骨折复位质量、闭合复位失败率、术中失血量、手术时间、透视次数、骨折愈合时间及术后1年Harris评分。结果与结论:(1)A组患者复位效果优于B组,手术时间减少了13 min,术中出血量减少了50.65 m L,透视次数减少了18.59次,术后1年Harris评分增加了10.58分,2组比较差异有显著性意义(P<0.05);(2)提示对于难复性股骨转子间骨折,侧卧位手法牵引复位股骨近端防旋髓内钉固定可以缩短复位操作时间,减少术中血液丢失,提高复位质量,较牵引床复位更有优势。展开更多
基金supported financially by the National Natural Science Foundation of China(Nos.31401053 and 31471966)Guangdong Provincial Natural Science Foundation of China(No.2015A030313903)+1 种基金GDAS Special Project of Science and Technology Development(2017GDASCX-0107)the Funds for Environment Construction and Capacity Building of GDAS’Research Platform(2016GDASPT-0107)
文摘Temperature-dependent sex determination（TSD） is a type of environmental sex determination in which the sex of the embryos depends on the ambient temperature; however,the molecular mechanisms governing this process remain unknown.Aromatase,encoded by the cyp19a1 gene,which converts androgens into estrogens in animals,was considered to be the key gene for TSD.In this study,the 5＇-flanking region of the cyp19a1 gene in Reeves＇ turtle（Mauremys reevesii） was cloned,and the promoter region was identified using the luciferase reporter assay.Then the eggs of Reeves＇ turtle were incubated at different temperatures（26°C： male-biased temperature; 29°C： non-sex-biased temperature and 32°C： female-biased temperature）.During the thermosensitive period,the adrenal kidney gonad complexes（AKG） were sampled.DNA methylation analysis of the AKG samples showed that the promoter region of the cyp19a1 gene was significantly de-methylated in the female-biased temperature regime（P＆lt;0.01）.Quantitative analysis of the cyp19a1 gene and estrogen by q PCR and Elisa assay showed that the expression level of the cyp19a1 gene and estrogen content were both upregulated significantly at the female-biased temperature（P＆lt;0.01）.These results indicated that the de-methylation response of the cyp19a1 gene to incubation temperature,especially at the female-biased temperature,could lead to temperature-specific expression of aromatase and increased estrogen levels,which may further determine gonadal development in Reeves＇ turtle.These findings provide insights into the genetic mechanisms underlying TSD.
文摘背景:难复性股骨转子间骨折往往无法通过牵引床牵引得到良好的复位,需要切开或者应用其他微创复位技术进行辅助复位。目的:探讨侧卧位牵引复位股骨近端防旋髓内钉固定对难复性股骨转子间骨折的复位效果。方法:回顾性分析2013年5月至2015年8月收治的84例难复性股骨转子间骨折患者的资料,均为新鲜骨折,骨折按AO分型:A2型26例,A3型58例。根据骨折复位方法的不同,分为侧卧位手法牵引复位组(A组)和平卧位牵引床牵引复位组(B组),每组42例。分析比较2组患者骨折复位质量、闭合复位失败率、术中失血量、手术时间、透视次数、骨折愈合时间及术后1年Harris评分。结果与结论:(1)A组患者复位效果优于B组,手术时间减少了13 min,术中出血量减少了50.65 m L,透视次数减少了18.59次,术后1年Harris评分增加了10.58分,2组比较差异有显著性意义(P<0.05);(2)提示对于难复性股骨转子间骨折,侧卧位手法牵引复位股骨近端防旋髓内钉固定可以缩短复位操作时间,减少术中血液丢失,提高复位质量,较牵引床复位更有优势。
