Growth hormone signaling is necessary for lifespan extension by dietary methionine

Growth hormone significantly impacts lifespan in mammals. Mouse longevity is extended when growth hormone (GH) signaling is interrupted but markedly shortened with high‐plasma hormone levels. Methionine metabolism is enhanced in growth hormone deficiency, for example, in the Ames dwarf, but suppressed in GH transgenic mice. Methionine intake affects also lifespan, and thus, GH mutant mice and respective wild‐type littermates were fed 0.16%, 0.43%, or 1.3% methionine to evaluate the interaction between hormone status and methionine. All wild‐type and GH transgenic mice lived longer when fed 0.16% methionine but not when fed higher levels. In contrast, animals without growth hormone signaling due to hormone deficiency or resistance did not respond to altered levels of methionine in terms of lifespan, body weight, or food consumption. Taken together, our results suggest that the presence of growth hormone is necessary to sense dietary methionine changes, thus strongly linking growth and lifespan to amino acid availability.     

Development of co-dominant KASP markers co-segregating with Ug99 effective stem rust resistance gene <Emphasis Type="Italic">Sr26</Emphasis> in wheat

Stem rust of wheat, caused by Puccinia graminis f. sp. tritici (Pgt), is a threat to global food security due to its ability to cause total crop failures. The Pgt race TTKSK (Ug99) and its derivatives detected in East Africa carry virulence for many resistance genes present in modern cultivars. However, stem rust resistance gene Sr26 remains effective to all races of Pgt worldwide. Sr26 is carried on the Agropyron elongatum (syn. Thinopyrum ponticum) segment 6Ae#1L translocated to chromosome 6AL of wheat. In this study, a recombinant inbred line (RIL) population derived from a cross between the landrace Aus27969 and Avocet S, which carries Sr26, was used to develop co-dominant kompetitive allele-specific polymerase chain reaction (KASP) markers that co-segregate with Sr26. Four KASP markers (sunKASP_216, sunKASP_218, sunKASP_224 and sunKASP_225) were also shown to co-segregate with Sr26 in four additional RIL populations. When tested on Australian cultivars and breeding lines, these markers amplified alleles alternate to that linked with Sr26 in all cultivars known to lack this gene and Sr26-linked alleles in cultivars and genotypes known to carry Sr26. Genotypes WA-1 and WA-1/3*Yitpi carrying the shortest Sr26 translocation segment were positive only for markers sunKASP_224 and sunKASP_225. Our results suggest the four KASP markers are located on the original translocation and sunKASP_224 and sunKASP_225 are located on the shortened version. Therefore, sunKASP_224 and sunKASP_225 can be used for marker-assisted pyramiding of Sr26 with other stem rust resistance genes to achieve durable resistance in wheat.     

Indole acids as a novel PDE2 inhibitor chemotype that demonstrate pro-cognitive activity in multiple species

An internal HTS effort identified a novel PDE2 inhibitor series that was subsequently optimized for improved PDE2 activity and off-target selectivity. The optimized lead, compound 4, improved cognitive performance in a rodent novel object recognition task as well as a non-human primate object retrieval task. In addition, co-crystallization studies of close analog of 4 in the PDE2 active site revealed unique binding interactions influencing the high PDE isoform selectivity.     

DEVELOPMENTAL ANATOMY OF JUVENILE AND ADULT SHOOTS OF MARCGRAVIA RECTIFOLIA L

Marcgravia rectifolia L. is a dimorphic vine having distinct juvenile and adult shoots. The juvenile shoot is a climber characterized by an orthotropic growth habit, a flattened stem, adventitious roots, and ovate leaves. The adult shoot, on the other hand, possesses a plagiotropic growth habit, has a cylindrical stem, few or no adventitious roots, and lanceolate leaves. Both phases have distichous phyllotaxy, however the plastochron is shorter for the adult phase than for the juvenile. Internode elongation occurs earlier for adult shoots than for juvenile shoots. Cytological analyses show the flattened stem of the juvenile results from differential production of cells, especially in the pith region. On the other hand, internodes of the adult phase are longer than juvenile internodes, a result of more cells produced rather than longer cells. In juvenile stems a perivascular band of elongated fibers develops, while in adult stems this band consists of brachyosclereids. Both phases undergo secondary growth and have non-storied cambia. Cambial activity begins in the 6th internode of each phase. As secondary growth proceeds, the adult stem produces much more xylem than juvenile stems of the same age. Adventitious roots produced in the juvenile stem are located in vertical rows at the “corners” of flattened stems and are attachment structures aiding the climbing habit of this vine. Phase changes occur regularly in this species. The juvenile phase usually transforms into the adult, however the adult phase can spontaneously revert back into the juvenile phase. The anatomical features and the phase changes are discussed and compared to Hedera helix, a vine whose phase changes have been studied in some detail. It is suggested that the anatomical features of Marcgravia rectifolia L. including its phase changes, may provide an alternative system to study physiological changes similar to those done with Hedera helix.     

Pantropism of rabies virus in free-ranging rabid red fox Vulpes fulva

The fluorescent antibody and mouse inoculation tests were employed to study the pantropism of rabies virus in tissue from free-ranging red fox (Vulpes fulva) submitted for rabies diagnosis. Viral antigen was found in various organs and tissues of the body. The distribution of antigen within tissues is discussed in the light of the pathogenesis and potential excretion of the virus.     

Molecular markers for adult plant leaf rust resistance gene <Emphasis Type="Italic">Lr48</Emphasis> in wheat

Leaf rust of wheat, caused by Puccinia triticina, is an important disease throughout the world. The adult plant leaf rust resistance gene Lr48 reported in CSP44 was previously mapped in chromosome 2B, but the marker–gene association was weak. In this study, we confirmed the location of Lr48 to be in the short arm of chromosome 2B and identified closely linked markers suitable for use in breeding. The CSP44/WL711 recombinant inbred line (RIL) population (90 lines) showed monogenic segregation for Lr48. Twelve resistant and 12 susceptible RILs were used for selective genotyping using an iSelect 90K Infinium SNP assay. Closely linked SNPs were converted into Kompetitive allele-specific primers (KASP) and tested on the parental lines. KASP markers giving clear clusters for alternate genotypes were assayed on the entire RIL population. SNP markers IWB31002, IWB39832, IWB34324, IWB72894 and IWB36920 co-segregated with Lr48 and the marker IWB70147 was mapped 0.3 cM proximal to this gene. Closely linked KASP markers were tested on a set of Australian and Nordic wheat genotypes. The amplification of SNP alleles alternate to those linked with Lr48 in the majority of the Australian and Nordic wheat genotypes demonstrated the usefulness of these markers for marker-assisted pyramiding of Lr48 with other rust resistance genes.