Unreduced spore formation in a spontaneous chimeric pinnule in an artificially produced haploid Anisocampium niponicum (Athyriaceae, Polypodiales).

Haploid sporophytes of Anisocampium niponicum with 2n = 40, were produced artificially by induced apogamy in vitro. They were subsequently transplanted into pots and two of them have been cultivated for the investigation of sporogenesis and/or production of chimera for more than 20 years. Haploid A. niponicum is sterile, but an abnormal chimeric pinnule that developed spontaneously in a single frond produced sporangia with spores. Each sporangium bore approximately 32 spores that were almost uniform in size. Sowing of these spores resulted in 50 gametophytes. Of 20 gametophytes cultured individually, five produced sporophytes apogamously after eight months. Both the gametophytes and subsequent apogamous sporophytes showed a chromosome number of 2n = 40. Our study demonstrates that a haploid sporophyte offspring can be produced from a haploid mother sporophyte via haploid spores. Since asexual reproduction is a prominent evolutionary process in ferns, the reproduction of a haploid A. niponicum sporophyte by unreduced spore formation might help to elucidate how apogamous ferns occur and evolve.

Optimizing Organ-Preservation Strategies Through Chemotherapy-Based Selection in Esophageal Squamous Cell Carcinoma: Results From the CROC Multi-Institutional Phase 2 Clinical Trial.

PURPOSE: This study aimed to assess the viability of definitive chemoradiotherapy (dCRT) as an organ-preservation strategy for remarkable responders who were downstaged to stage IA after receiving induction chemotherapy for resectable esophageal squamous cell carcinoma (ESCC). METHODS AND MATERIALS: Chemotherapy-naïve patients with resectable ESCC (stage IB-III, Union for International Cancer Control, International Cancer Control seventh edition) were eligible for the study. All patients received 3 cycles of docetaxel, cisplatin, and 5-FU (DCF) therapy (docetaxel 75 mg/m2 on day 1, cisplatin 75 mg/m2 on day 1, and 5-fluorouracil [5-FU] 750 mg/m2 on days 1-5, repeated every 3 weeks). Remarkable response was defined as a reduction in the tumor to T1, metastatic lymph nodes <1 cm on the short axis, and downstaging to stage IA after 3 cycles of DCF therapy. Remarkable responders then underwent dCRT, which included 2 courses of cisplatin 75 mg/m2 and 5-FU 1000 mg/m2 on days 1 to 4, repeated every 4 weeks, along with 50.4 Gy of concurrent radiation therapy. The primary endpoint was 1-year progression-free survival in remarkable responders following DCF therapy and subsequent dCRT. Secondary endpoints included 3-year overall survival (OS) and esophagectomy-free survival. RESULTS: Of the 92 patients registered, 90 were analyzed. A remarkable response to 3 courses of DCF therapy was observed in 58.4% of patients. Among these responders, 89.8% achieved a complete response after dCRT. During the median follow-up period of 33 months (range, 1-85 months), the 1-year progression-free survival was 89.8% (95% confidence interval [CI], 77.2%-95.6%, primary endpoint), and the 3-year OS was 83.7%. The 3-year OS and esophagectomy-free survival rates in the analysis group were 74.1% and 45.3%, respectively. An 18F-fluorodeoxyglucose-positron emission tomography response after 2 courses of DCF therapy was significantly associated with OS (P = .0049). CONCLUSIONS: In patients with resectable ESCC, dCRT for remarkable responders downstaging to stage IA after induction chemotherapy with 3 courses of DCF therapy is a feasible treatment option and provides an optimizing organ-preservation strategy of chemotherapy-based selection.