Chromosome-scale genome assembly of Cucumis hystrix-a wild species interspecifically cross-compatible with cultivated cucumber

Cucumis hystrix Chakr.(2n=2x=24)is a wild species that can hybridize with cultivated cucumber(C.sativus L.,2n=2x=14),a globally important vegetable crop.However,cucumber breeding is hindered by its narrow genetic base.Therefore,introgression from C.hystrix has been anticipated to bring a breakthrough in cucumber improvement.Here,we report the chromosome-scale assembly of C.hystrix genome(289 Mb).Scaffold N50 reached 14.1 Mb.Over 90%of the sequences were anchored onto 12 chromosomes.A total of 23,864 genes were annotated using a hybrid method.Further,we conducted a comprehensive comparative genomic analysis of cucumber,C.hystrix,and melon(C.melo L.,2n=2x=24).Whole-genome comparisons revealed that C.hystrix is phylogenetically closer to cucumber than to melon,providing a molecular basis for the success of its hybridization with cucumber.Moreover,expanded gene families of C.hystrix were significantly enriched in“defense response,”and C.hystrix harbored 104 nucleotide-binding site-encoding disease resistance gene analogs.Furthermore,121 genes were positively selected,and 12(9.9%)of these were involved in responses to biotic stimuli,which might explain the high disease resistance of C.hystrix.The alignment of whole C.hystrix genome with cucumber genome and self-alignment revealed 45,417 chromosome-specific sequences evenly distributed on C.hystrix chromosomes.Finally,we developed four cucumber-C.hystrix alien addition lines and identified the exact introgressed chromosome using molecular and cytological methods.The assembled C.hystrix genome can serve as a valuable resource for studies on Cucumis evolution and interspecific introgression breeding of cucumber.

Retrospective study of the efficacy and complication of thoracoabdominal incision for nephrectomy: a comparison with flank approach

This retrospective study was performed to compare the outcome of thoracoabdominal incision versusflank incision for radical nephrectomy in the patients with large renal tumors.A questionnaire assessing postopera-tive pain,administration of pain medications and the return to activities and work was sent to the patients who underwent radical nephrectomy through the 11th rib(group 1:undergoingflank incision,including 96 patients)or the 9th to 10th rib(group 2:undergoing thoracoabdom-inal incision,including 98 patients)from 2003 to 2007 in our hospital.A case retrospective analysis assessing operation time,perioperative hemorrhage volume,size of tumor,success in the treatment of tumor thrombus in renal vein or vena cava,time length of presence of drainage tube,postoperative analgesia usage and length of stay was conducted in patients whose questionnaires were returned.A total of 56 patients(58%)in group 1 and 60(61%)in group 2 responded to the questionnaire.Time lengths of operation and presence of abdominal drainage tube were shorter in group 2 than those in group 1.Perioperative hemorrhage volume in group 2 was obviously less than that in group 1.The mean size of tumors in group 1 was significantly smaller than that in group 2(P<0.0005).The success rate of treating thrombus in renal vein or vena cava in group 2 was significantly higher than that in group 1(P<0.05).Lengths of off-bed time and stay were the same in both groups.There were no differences between groups in terms of pain severity on postoperative day 1,on day of discharge and 1 month postoperatively(P>0.05).There were no significant differences between groups in the time following surgery when pain completely disappeared,when pain medications were discontinued,and when the patient returned to daily activities and work(P>0.05).The thoracoabdominal incision provides excellent exposure and allows for early vascular control.Efficacy and complication was comparable for thoracoabdominal andflank incisions in terms of incisional pain,analgesic requirements after discharge and return to normal activities.