De novo construction of mammalian synthetic inhibitory transcription factor and promoter pairs / 生物工程学报

Transcriptional regulation is crucial for regulated gene expression. Due to the complexity, it has been difficult to engineer eukaryotic transcription factor (TF) and promoter pairs. The few availabilities of eukaryotic TF and promotor pairs limit their practical use for clinical or industrial applications. Here, we report a de novo construction of synthetic inhibitory transcription factor and promoter pairs for mammalian transcriptional regulation. The design of synthetic TF was based on the fusion of DNA binding domain and Kruppel associated box transcription regulating domain (KRAB). The synthetic promoter was constructed by inserting the corresponding TF response element after SV40 promoter. We constructed and tested five synthetic inhibitory transcription factor and promoter pairs in cultured mammalian cells. The inhibition capability and orthogonality were verified by flow cytometry. In summary, we demonstrate the feasibility of constructing mammalian inhibitory TF and promoter pairs, which could be standardized for advanced gene-circuit design and various applications in the mammalian synthetic biology.

Application of thin-section computed tomographic images in measurement of safe range from foramen rotundum to siphon of internal carotid artery for operation through pterygopalatine fossa / 吉林大学学报(医学版)

Objective:To measure the safe range from the foramen rotundum to the siphon of internal carotid artery using three-dimensional reconstruction technique, and to provide guidance for operation through pterygopalatine fossa.Methods:The skulls of 121 volunteers were scanned to get the final results with thin-section computed tomographic images.The position of the siphon of internal carotid artery (point A)and foramen rotundum (pointB)were ascertained.Three-dimensional reconstruction technique was used to build a coordinate system paralleled to the frankfort horizontal plane and the nasal septum plane.The coordinate system took point A as the coordinate origin.Point C and point D were the projections of point A in two planes parallel with frankfort horizontal plane and nasal septum plane which included point B.The distances of AC,AB,and BC were measured. The angles of the line went through A and B to the three planes were also measured.Results:The distance of AC was measured as 13.22 (3.79)mm (range,8.33 - 105.67 mm;95%CI:8.55 - 21.39 mm).The angle to the sagittal plane was measured as 33.54 (9.23)° (range,5.38- 66.58°;95%CI:30.88 - 34.20°). The angle to the coronal plane was measured as 53.17 (10.48)°(range,5.60-75.02°;95%CI:51.29-55.06°).The angle to the horizontal plane was measured as 9.43 (12.91 ) mm (range,- 28.44 - 82.22;95% CI:7.11 - 11.76 ). Conclusion:The safety distance from foramen rotundum to the siphon of internal carotid artery in the operation through pterygopalatine fossa (PPF) under nasoendoscope is obtained by thin-section computed tomographic images.