Early maternal loss leads to short-but not long-term effects on diurnal cortisol slopes in wild chimpanzees

The biological embedding model (BEM) suggests that fitness costs of maternal loss arise when early-life experience embeds long-term alterations to hypothalamic-pituitary-adrenal (HPA) axis activity. Alternatively, the adaptive calibration model (ACM) regards physiological changes during ontogeny as short-term adaptations. Both models have been tested in humans but rarely in wild, long-lived animals. We assessed whether, as in humans, maternal loss had short-and long-term impacts on orphan wild chimpanzee urinary cortisol levels and diurnal urinary cortisol slopes, both indicative of HPA axis functioning. Immature chimpanzees recently orphaned and/or orphaned early in life had diurnal cortisol slopes reflecting heightened activation of the HPA axis. However, these effects appeared short-term, with no consistent differences between orphan and non-orphan cortisol profiles in mature males, suggesting stronger support for the ACM than the BEM in wild chimpan-zees. Compensatory mechanisms, such as adoption, may buffer against certain physiological effects of maternal loss in this species

High expression level of a gene coding for a chloroplastic amino acid selective channel protein is correlated to cold acclimation in cereals

A cold-regulated gene (cor tmc-ap3) coding for a putative chloroplastic amino acid selective channel protein wasisolated from cold-treated barley leaves combining the differential display and the 50-RACE techniques. Cor tmcap3is expressed at low level under normal growing temperature, and its expression is strongly enhanced aftercold treatment. A positive correlation between the expression of cor tmc-ap3 and frost tolerance was found bothamong barley cultivars and among cereal species. The COR TMC-AP3 protein was expressed in vitro, purifiedand used to raise a polyclonal antibody.Western analysis showed that the cor tmc-ap3 gene product is localized tothe chloroplastic outer envelope fraction, supporting its putative function. The frost-resistant winter cultivar Oniceaccumulated COR TMC-AP3 more rapidly and at a higher level than the frost-susceptible spring cultivar Gitane.After 28 days of cold acclimation the winter cultivar had about 2-fold more protein than the spring genotype.All these results suggest that an increased amount of a chloroplastic amino acid selective channel protein couldbe required for cold acclimation in cereals. Hypotheses about the role of COR TMC-AP3 during the hardeningprocess are discussed

Identification and mapping of a new leaf stripe resistance gene in barley (Hordeum vulgare L.)

Pyrenophora graminea is the seed-bornepathogen causal agent of barley leaf stripe disease. Nearisogeniclines (NILs) carrying resistance of the cv “Thibaut”against the highly virulent isolate Dg2 were obtainedby introgressing the resistance into the geneticbackground of the susceptible cv “Mirco”. The segregationof the resistance gene was followed in a F2 populationof 128 plants as well as on the F3 lines derived fromthe F2 plants; the segregation fitted the 1:2:1 ratio for asingle gene. By using NILs, a RAPD marker associatedwith the resistance gene was identified; sequence-specific(STS) primers were designed on the basis of the ampliconsequence and a RILs mapping population with anAFLP-based map were used to position this molecularmarker to barley chromosome 1 S (7HS). STS and CAPSmarkers were developed from RFLPs mapped to thetelomeric region of barley chromosome 7HS and threepolymorphic PCR-based markers were developed. Thesegregation of these markers was followed in the F2 populationand their map position with respect to the resistancegene was determined. Our results indicate that theThibaut resistance gene, which we designated as Rdg2a,maps to the telomeric region of barley chromosome 7HSand is flanked by the markers OPQ-9700 and MWG 2018at distances of 3.1 and 2.5 cM respectively. The suitabilityof the PCR-based marker MWG2018 in selectionassistedbarley breeding programs is discussed

Towards the construction of a high density genetic linkage map of wheat chromosome 5A

A high density genetic map is needed for anchoring BAC contigs during the construction of a physical map and for DNA sequence assembly. The International Wheat Genome Sequencing Consortium is dedicated to the development of physical maps of individual chromosomes as the first step towardsthe whole genome sequencing of hexaploid wheat. To undertake this challenge for wheat chromosome 5A, we rely on several mapping populations and different parallel approaches formarker development. Three mapping populations are being used: 1) a Chinese Spring x Renan (CSxR) F2 population; 2) an F2 population derived from CS x CS-Triticum dicoccoides disomicsubstitution line for chromosome 5A and, 3) a RIL (Recombinant Inbred Lines) population derived from Langdon (LDN) x LDN-T. dicoccoides disomic substitution line for chromosome 5A. For marker development, a Diversity Array Technology (DArT) platform specific for the short and long arms of wheat chromosome 5A has been established using DNA from flow sorted chromosomes, and includes more than 6000 wheat probes. So far, this array is under hybridization with one population (CS x R) while the other two populations are in the pipeline. Besides the DArTs, a set of SSR, RFLP-derivedand EST-derived PCR-based markers, specific for 5AS and/or 5AL chromosome arms have been selected from databases and literature. After the assignment to chromosome 5A, performed using CS deletion and aneuploid lines, the markers are being tested for polymorphism between the parents of the three mapping populations. Polymorphic DNA fragments, specific for 5A, will be mapped in the available population(s). The resulting genetic linkage map of the wheat chromosome 5A will bepresented