RESUMO
We created waxy corn hybrids by CRISPR-Cas9 editing of a waxy allele in 12 elite inbred maize lines, a process that was more than a year faster than conventional trait introgression using backcrossing and marker-assisted selection. Field trials at 25 locations showed that CRISPR-waxy hybrids were agronomically superior to introgressed hybrids, producing on average 5.5 bushels per acre higher yield.
Assuntos
Proteínas de Plantas/genética , Locos de Características Quantitativas , Zea mays/crescimento & desenvolvimento , Sistemas CRISPR-Cas , Produção Agrícola , Edição de Genes/métodos , Introgressão Genética , Deleção de Sequência , Zea mays/genéticaRESUMO
We present a case of a 71-year-old man with a history of liver transplantation who was treated with adjuvant radiotherapy with concurrent cisplatin for recurrent cutaneous squamous cell carcinoma of the head and neck. The patient was transitioned from tacrolimus to sirolimus for immunosuppression immediately prior to the start of radiation therapy, with the goal of reducing the risk for further skin cancer recurrence. The patient developed severe normal tissue toxicity, disproportionate to the dose delivered. He was diagnosed with Grade 4 esophagitis and mucositis after just 2,400 cGy in 12 fractions (planned 6,400 cGy in 32 fractions), requiring cessation of therapy. Six months later, the patient was diagnosed with local recurrence and distant metastases in the lung, and unfortunately passed away one month later. Randomized data have demonstrated the anti-neoplastic benefit of sirolimus. Pre-clinical studies and animal models have suggested that sirolimus may be a radiation sensitizer; however, the literature is limited regarding the clinical translation of these biologic findings. The case we presented reflects that concurrent radiation therapy with sirolimus may enhance the cytotoxic effects of radiation therapy and contribute to dose-limiting toxicity. Certainly, further study is necessary to explore this observation.
