The chromosome region including the earliness per se locus Eps-Am1 affects the duration of early developmental phases and spikelet number in diploid wheat

Earliness per se genes are those that regulate flowering time independently of vernalization and photoperiod, and are important for the fine tuning of flowering time and for the wide adaptation of wheat to different environments. The earliness per se locus Eps-Am1 was recently mapped within a 0.8 cM interval on chromosome 1AmL of diploid wheat Triticum monococcum L., and it was shown that its effect was modulated by temperature. In this study, this precise mapping information was used to characterize the effect of the Eps-Am1 region on both duration of different developmental phases and spikelet number. Near isogenic lines (NILs) carrying the Eps-Am1-l allele from the cultivated accession DV92 had significantly longer vegetative and spike development phases (P <0.0001) than NILs carrying the Eps-Am1-e allele from the wild accession G3116. These differences were paralleled by a significant increase in the number of spikelets per spike, in both greenhouse and field experiments (P <0.0001). Significant interactions between temperature and Eps-Am1 alleles were detected for heading time (P <0.0001) but not for spikelet number (P=0.67). Experiments using NILs homozygous for chromosomes with recombination events within the 0.8 cM Eps-Am1 region showed that the differences in number of spikelets per spike were linked to the differences in heading time controlled by the Eps-Am1 locus. These results indicate that the differences in these two traits are either pleiotropic effects of a single gene or the effect of closely linked genes. A similar effect on spikelet number was detected in the distal region of chromosome 1AL in common wheat (T. aestivum L.)

Genetic dissection of photoperiod response based on GWAS of pre-anthesis phase duration in spring barley

Heading time is a complex trait, and natural variation in photoperiod responses is a major factor controlling time to heading, adaptation and grain yield. In barley, previous heading time studies have been mainly conducted under field conditions to measure total days to heading. We followed a novel approach and studied the natural variation of time to heading in a world-wide spring barley collection (218 accessions), comprising of 95 photoperiod-sensitive (Ppd-H1) and 123 accessions with reduced photoperiod sensitivity (ppd-H1) to long-day (LD) through dissecting pre-anthesis development into four major stages and sub-phases. The study was conducted under greenhouse (GH) conditions (LD; 16/8 h; ∼20/∼16°C day/night). Genotyping was performed using a genome-wide high density 9K single nucleotide polymorphisms (SNPs) chip which assayed 7842 SNPs. We used the barley physical map to identify candidate genes underlying genome-wide association scans (GWAS). GWAS for pre-anthesis stages/sub-phases in each photoperiod group provided great power for partitioning genetic effects on floral initiation and heading time. In addition to major genes known to regulate heading time under field conditions, several novel QTL with medium to high effects, including new QTL having major effects on developmental stages/sub-phases were found to be associated in this study. For example, highly associated SNPs tagged the physical regions around HvCO1 (barley CONSTANS1) and BFL (BARLEY FLORICAULA/LEAFY) genes. Based upon our GWAS analysis, we propose a new genetic network model for each photoperiod group, which includes several newly identified genes, such as several HvCO-like genes, belonging to different heading time pathways in barley

Determinantes genéticos de la calidad panadera de los trigos argentinos

Las gluteninas de alto (HMW-GS) y bajo (LMW-GS) peso molecular son las proteínas de reserva más importantes en la determinación de la calidad panadera del trigo y su caracterización es indispensable para una eficiente manipulación de la calidad durante el mejoramiento. En este trabajo se determinó la composición de HMW-GS mediante SDS-PAGE y marcadores moleculares en 112 cultivares argentinos y se calculó el índice de calidad GLU-1. Se encontró una alta frecuencia de los alelos con índice máximo en las HMW-GS de los loci GÍU-A1 (96%), Glu-Bl (72%), y GIu-D1 (88%) lo que determinó que el 63 % de los cultivares estudiados presenten una composición óptima de HMW-GS (GLU-1 = 10). La correlación positiva entre el índice GLU1 y la calidad panadera en tres subconjuntos de cultivares argentinos confirmaron el valor predictivo de este índice.Trabajo galardonado con el Premio "Molinos Brunning", versión 1996.Academia Nacional de Agronomía y Veterinaria (ANAV

Determinantes genéticos de la calidad panadera de los trigos argentinos

Las gluteninas de alto (HMW-GS) y bajo (LMW-GS) peso molecular son las proteínas de reserva más importantes en la determinación de la calidad panadera del trigo y su caracterización es indispensable para una eficiente manipulación de la calidad durante el mejoramiento. En este trabajo se determinó la composición de HMW-GS mediante SDS-PAGE y marcadores moleculares en 112 cultivares argentinos y se calculó el índice de calidad GLU-1. Se encontró una alta frecuencia de los alelos con índice máximo en las HMW-GS de los loci GÍU-A1 (96%), Glu-Bl (72%), y GIu-D1 (88%) lo que determinó que el 63 % de los cultivares estudiados presenten una composición óptima de HMW-GS (GLU-1 = 10). La correlación positiva entre el índice GLU1 y la calidad panadera en tres subconjuntos de cultivares argentinos confirmaron el valor predictivo de este índice.Trabajo galardonado con el Premio "Molinos Brunning", versión 1996.Academia Nacional de Agronomía y Veterinaria (ANAV

Registration of ‘BIOINTA 2004’ Wheat

'BIOINTA 2004' (Reg. No. CV-1030, PI 655312) is a hard red winter wheat (Triticum aestivum L.) developed and released by the Marcos Juárez Experimental Station from the National Wheat Breeding Program of the National Institute of Agricultural Technology, Argentina. BIOINTA 2004, previously designated R4001, was selected for its excellent grain yield potential, resistance to leaf rust (caused by Puccinia triticina Eriks.) conferred mainly by the Lr47 gene selected by marker assisted selection (MAS), and its good bread-making quality. © Crop Science Society of America

Loss of p53 Ser18 and Atm Results in Embryonic Lethality without Cooperation in Tumorigenesis

Phosphorylation at murine Serine 18 (human Serine 15) is a critical regulatory process for the tumor suppressor function of p53. p53Ser18 residue is a substrate for ataxia-telangiectasia mutated (ATM) and ATM-related (ATR) protein kinases. Studies of mice with a germ-line mutation that replaces Ser18 with Ala (p53S18A mice) have demonstrated that loss of phosphorylation of p53Ser18 leads to the development of tumors, including lymphomas, fibrosarcomas, leukemia and leiomyosarcomas. The predominant lymphoma is B-cell lymphoma, which is in contrast to the lymphomas observed in Atm−/− animals. This observation and the fact that multiple kinases phosphorylate p53Ser18 suggest Atm-independent tumor suppressive functions of p53Ser18. Therefore, in order to examine p53Ser18 function in relationship to ATM, we analyzed the lifespan and tumorigenesis of mice with combined mutations in p53Ser18 and Atm. Surprisingly, we observed no cooperation in survival and tumorigenesis in compound p53S18A and Atm−/− animals. However, we observed embryonic lethality in the compound mutant animals. In addition, the homozygous p53Ser18 mutant allele impacted the weight of Atm−/− animals. These studies examine the genetic interaction of p53Ser18 and Atm in vivo. Furthermore, these studies demonstrate a role of p53Ser18 in regulating embryonic survival and motor coordination

Control of flowering time and spike development in cereals: the earliness per se Eps-1 region in wheat, rice, and Brachypodium

The earliness per se gene Eps-Am1 from diploid wheat Triticum monococcum affects heading time, spike development, and spikelet number. In this study, the Eps1 orthologous regions from rice, Aegilops tauschii, and Brachypodium distachyon were compared as part of current efforts to clone this gene. A single Brachypodium BAC clone spanned the Eps-Am1 region, but a gap was detected in the A. tauschii physical map. Sequencing of the Brachypodium and A. tauschii BAC clones revealed three genes shared by the three species, which showed higher identity between wheat and Brachypodium than between them and rice. However, most of the structural changes were detected in the wheat lineage. These included an inversion encompassing the wg241-VatpC region and the presence of six unique genes. In contrast, only one unique gene (and one pseudogene) was found in Brachypodium and none in rice. Three genes were present in both Brachypodium and wheat but were absent in rice. Two of these genes, Mot1 and FtsH4, were completely linked to the earliness per se phenotype in the T. monococcum high-density genetic map and are candidates for Eps-Am1. Both genes were expressed in apices and developing spikes, as expected for Eps-Am1 candidates. The predicted MOT1 protein showed amino acid differences between the parental T. monococcum lines, but its effect is difficult to predict. Future steps to clone the Eps-Am1 gene include the generation of mot1 and ftsh4 mutants and the completion of the T. monococcum physical map to test for the presence of additional candidate genes

Computational Refinement of Functional Single Nucleotide Polymorphisms Associated with ATM Gene

gene are the most common forms of genetic variations that account for various forms of cancer. However, the extent to which SNPs interferes with the gene regulation and affects cancer susceptibility remains largely unknown. gene. gene function can aid in better understanding of genetic differences in disease susceptibility