Drought stress is a constant threat to rice production worldwide. Most modern rice cultivars are sensitive to drought, and the effect is severe at the reproductive stage. Conventional breeding for drought resistant (DR) rice varieties is slow and limited due to the quantitative nature of the DR traits. Identification of genes (QTLs)/markers associated with DR traits is a prerequisite for marker-assisted breeding. Grain yield is the most important trait and to this end drought yield QTLs have been identified under field conditions. The present study reports identification of drought yield QTLs under controlled conditions without confounding effects of other factors prevalent under natural conditions. A linkage map covering 1,781.5 cM with an average resolution of 9.76 cM was constructed using an F2 population from a cross between two Japonica cultivars, Cocodrie (drought sensitive) and Vandana (drought tolerant) with 213 markers distributed over 12 rice chromosomes. A subset of 59 markers (22 genic SSRs and 37 SNPs) derived from the transcriptome of the parents were also placed in the map. Single marker analysis using 187 F2 : 3 progeny identified 6 markers distributed on chromosomes 1, 5, and 8 to be associated with grain yield under drought (GYD). Composite interval mapping identified six genomic regions/quantitative trait loci (QTL) on chromosome 1, 5, 8, and 9 to be associated with GYD. QTLs located on chromosome 1 (qGYD1.2, qGYD1.3), chromosome 5 (qGYD5.1) and chromosome 8 (qGYD8.1) were contributed by Vandana alleles, whereas the QTLs, qGYD1.1 and qQYD9.1 were contributed by Cocodrie alelles. The additive positive phenotypic variance explained by the QTLs ranged from 30.0 to 34.0%. Candidate genes annotation within QTLs suggested the role of transcription factors and genes involved in osmotic potential regulation through catalytic/metabolic pathways in drought tolerance mechanism contributing to yield.

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Neither FAMTX nor FEMTX can be advocated as adjuvant treatment in patients who undergo resection for gastric cancer.

Truncating mutations in the AXIN2 gene, a key regulator of b-catenin degradation in the Wnt pathway, have been reported in three families with gastrointestinal adenomatous polyposis and features of ectodermal dysplasia. However, the role of AXIN2 in familial adenomatous polyposis (FAP) syndrome is not completely understood. We performed an in-depth study of APC and MUTYH, and ruled out their implication in 23 FAP families. We then investigated the role of other genes involved in the Wnt pathway, including AXIN2, and identified a novel missense variant in AXIN2 in one family with attenuated FAP. Carriers of the variant exhibited a variable number of polyps but none showed any sign of ectodermal dysplasia. We have demonstrated the pathogenicity of this novel variant by establishing its low frequency in controls as well as by LOH analysis, a segregation study, and immunofluorescent staining of AXIN2 and b-catenin proteins. This report expands the phenotype known to be related to AXIN2 alterations and raises the question of whether to screen AXIN2 in FAP cases negative for alterations in APC and MUTYH. European Journal of Human Genetics (2014) 22, 423-426; doi:10.1038/ejhg.2013.146; published online 10 July 2013Keywords: familal adenomatous polyposis; AXIN2 mutation; oligodontia; ectodermal dysplasia; Wnt pathway INTRODUCTION Familial Adenomatous Polyposis (FAP) is a syndrome characterized by the development of hundreds of colorectal polyps in early adolescence; it predisposes sufferers to cancer and has dominant inheritance. Attenuated FAP (AFAP) is diagnosed when patients present with less (10-99) polyps, and tends to occur 15-20 years later than for classical FAP. Mutations in the APC gene are responsible for the majority of FAP cases, and also explain some AFAP cases. In 2002, the implication of MUTYH, a BER-pathway gene, was discovered in milder cases of polyposis. Nevertheless, a considerable proportion (20-50%) of FAP and AFAP cases is not found to carry germline mutations in APC or MUTYH, and their genetic etiology remains unclear.As APC has a key role in maintaining the b-catenin turnover in the Wnt pathway, other Wnt genes involved in this regulation might be also implicated in the syndrome. It has been suggested that AXIN2, the scaffold protein of the b-catenin destruction complex, is the main negative regulator in the pathway. 1 Little is known regarding the role of AXIN2 in CRC, but AXIN2 mutations have been reported in three families with gastrointestinal polyposis and ectodermal dysplasia; 2,3 the AXIN2 truncating mutations were located in a narrow region of the gene, and the phenotype associated with them, while highly heterogeneous, always included colonic polyposis and ectodermal dysplasia.Here we describe a family with a novel missense variant in the AXIN2 gene, and thereby expand on the phenotype associated with alterations in this gene.