Taxa-4(5),11(12)-diene is the precursor for paclitaxel biosynthesis. The diterpenoid paclitaxel (marketed as Taxol), a plant secondary metabolite isolated from yew, is an effective drug widely used in the treatment of numerous cancers. However, further application of taxol has been restricted due to its low yield in plants and the difficulties in extraction. To increase the intact isoprene flux, we constructed the fusion gene plasmid pBgGGTS and individual cassette plasmid pBgGGgTS to enhance the expression levels of geranylgeranyl diphosphate synthase gene (ggpps) and a taxadiene synthase gene (ts) in Coprinopsis cinerea. These two plasmids were separately transformed into C. cinerea LT2 strain, resulting in several putative transformants. Putative transformants were determined by PCR technique, indicating that 5 out of 13 putative transformants transformed by pBgGGTS and 6 out of 13 putative transformants transformed by pBgGGgTS, respectively. Additionally, the Southern blotting analysis of these 10 transformants confirmed that both ggpps and ts gene were stably integrated into the genome of C. cinerea. Crude extracts from each of the transformants were analyzed. There is no difference in the mycelium extracts among the wild-type LT2 and two types of transformants. However, analysis of culture filtrates indicated that an additional GC peak was found at the retention time of 16.762 min which was absent in the wild type control. The mass fragmentation pattern of this peak had the same diagnostic ions with taxa-4(5),11(12)-diene. According to peak area, the amounts of taxa-4(5),11(12)-diene in each fermented broth were 44 ng/L (transformed with pBgGGgTS) and 30 ng/L (transformed with pBgGGTS), respectively. In conclusion, co-expression of the ggpps and ts gene could increase the taxadiene production in C. cinerea.
Agaricales ; metabolism ; Alkenes ; metabolism ; Diterpenes ; metabolism ; Farnesyltranstransferase ; genetics ; metabolism ; Genetic Engineering ; Isomerases ; genetics ; metabolism ; Paclitaxel ; Plasmids

Objective:To explore the application value and treatment effects of multiple free anterolateral perforator flaps of calf for reconstruction of multiple digital wounds in single hand.Methods:From August 2020 to March 2022, 12 patients with soft tissue defects in 35 digits were treated in Department of Hand Surgery, Suzhou Ruihua Orthopaedic Hospital. Ten patients were male and 2 were female, aged 25 to 58 years old. Of the patients, 1 had soft tissue defects in 5 digits, 3 in 4 digits, 2 in 3 digits and 6 in 2 digits. The size of defects was from 1.2 cm ×1.2 cm to 7.0 cm×3.5 cm after debridement. The vascular perforators discovered from intraoperative explorations were found originating from the superficial peroneal artery in 24 flaps, from the peroneal artery in 7 flaps and from the anterior tibial artery in 4 flaps. During surgery, the perforator artery and accompanying veins of the flaps were anastomosed with the proper digital artery and palmar or dorsal subcutaneous veins in the recipient site, respectively. The size of the flaps was from 1.5 cm×1.5 cm to 7.5 cm×4.0 cm. No nerve was affected in the surgery. The wound at donor sites in the calf was sutured directly. Regular postoperative follow-ups were conducted at outpatient clinics. The comprehensive evaluation scale of flap was used to assess the conditions of the donor and recipient sites.Results:In this study, all 35 soft tissue defects of digits in 12 patients were reconstructed by the anterolateral perforator flaps of calf. All the 35 flaps survived after surgery, with a 100% of survival rate. The patients were instructed to carry out early functional training after surgery. Follow-up lasted 6 to 24 months, with an average of 11 months. Twenty-five flaps were found in slightly swollen, and further flap thinning surgery were carried out 3 months after the primary surgery, while the rest of the flaps had good appearance and texture. At 6 months after surgery, all flaps recovered a partial deep and shallow sensory and sense of touch. All wound at donor sites in calf had one-stage healing without dysfunction. The comprehensive evaluation scale was excellent in 28 flaps and good in 7 flaps. The excellent and good rate was 100%.Conclusion:It is an effective method to use multiple free anterolateral perforator flaps of calf to reconstruct multiple digit defects in single hand. The flaps can be conveniently harvested and the multiple digital defects in single hand can be reconstructed in primary surgery with small damages to the donor sites and together with satisfactory clinical outcomes.