Peroxidase activity in hooded and awned barley at successive stages of development

The hooded (KK) and awned (kk) genotypes of barley differ in the amount of peroxidase activity at various stages of development. In hooded, this activity is at most stages higher than in awned, but it varies more from one stage to another, so that at certain stages, particularly the first leaf stages of young plants, it is lower. The peroxidase enzymes of the two genotypes are alike in electrophoretic mobility. Since peroxidase activity is particularly high in meristems of hooded at the beginning of their transition from the vegetative to the flowering condition, which is shortly before the first effects on morphogenesis can be observed, a connection between high peroxidase activity and the morphogenetic effects appears likely.     

Genetics of barley tiller and leaf development

In cereals, tillering and leaf development are key factors in the concept of crop ideotype, introduced in the 1960 s to enhance crop yield, via manipulation of plant architecture. In the present review, we discuss advances in genetic analysis of barley shoot architecture,focusing on tillering, leaf size and angle. We also discuss novel phenotyping techniques, such as 2 D and 3 D imaging, that have been introduced in the era of phenomics, facilitating reliable trait measurement. We discuss the identification of genes and pathways that are involved in barley tillering and leaf development,highlighting key hormones involved in the control of plant architecture in barley and rice. Knowledge on genetic control of traits related to plant architecture provides useful resources for designing ideotypes for enhanced barley yield and performance.     

Genetics of CM-proteins (A-hordeins) in barley

Summary The CM-proteins, which are the main components of the A-hordeins, include four previously described proteins (CMa-1, CMb-1, CMc-1, CMd-1), plus a new one, CMe-1, which has been tentatively included in this group on the basis of its solubility properties and electrophoretic mobility. The variability of the five proteins has been investigated among 38 Hordeum vulgare cultivars and 17 H. spontaneum accessions. Proteins CMa-1, CMc-1 and CMd-1 were invariant within the cultivated species; CMd was also invariant in the wild one. The inheritance of variants CMb-1/CMb-2 and CMe-1/CMe-2,2 was studied in a cross H. spontaneum x H. vulgare. The first two proteins were inherited as codominantly expressed allelic variations of a single mendelian gene. Components CMe-2,2 were jointly inherited and codominantly expressed with respect to CMe-1. Gene CMb and gene(s) CMe were found to be unlinked. The chromosomal locations of genes encoding CM-proteins were investigated using wheat-barley addition lines. Genes CMa and CMc were associated with chromosome 1, and genes CMb and CMd with chromosome 4. These gene locations further support the proposed homoeology of chromosomes 1 and 4 of barley with chromosomes groups 7 and 4 of wheat, respectively. Gene(s) CMe has been assigned to chromosome 3 of barley. The accumulation of protein CMe-1 is totally blocked in the high lysine mutant Riso 1508 and partially so in the high lysine barley Hiproly.     

Genetics of phenotypic plasticity: QTL analysis in barley, Hordeum vulgare

Phenotypic plasticity is the variation in phenotypic traits produced by a genotype in different environments. In contrast, environmental canalization is defined as the insensitivity of a genotype's phenotype to variation in environments. Despite the extensive literature on the evolutionary significance and potential genetic mechanisms driving plasticity and canalization, few studies tried to unravel the genetic basis of this phenomenon. Using both simulations and real data from barley (Hordeum vulgare), we used QTL mapping to obtain insights into the genetics of phenotypic plasticity. We explored two ways of quantifying phenotypic plasticity, namely the phenotypic variance across environments and the Finlay-Wilkinson's regression slope. Each relates to a different concept of stability. Through QTL detection with real and simulated data, we show that each measure of plasticity detects specific types of plasticity QTL. Most of the plasticity QTLs were detected in the data set with the lowest number of environments. All plasticity QTL co-located with loci showing QTL x E interaction and there were no QTL that only affected plasticity. The number of environments that are considered and their homogeneity is a key to interpret the genetic control of phenotypic plasticity. Regulatory pathways of plasticity may vary from one set of environments to another due to unique features of each environment. Therefore, with an increasing number of environments, it may become impossible to detect a single 'consistent' regulatory pathway for all environments.     

Extrapair paternity in hooded warblers

We examined the role of extrapair fertilizations (EPFs) in themating system of the hooded warbler (Wilsonia citrina), a monogamoussongbird. DNA fingerprinting revealed that 8 of 17 (47%) femaleshad extrapair young in their first or second brood, and 23 of78 (29%) nestlings were the result of EPFs. Extrapair youngwere signifkandy more likely to occur in first broods than insecond broods. The proportion of EPFs within a brood was stronglybirnodal among broods: nests had 50% or more extrapair youngor none. In seven of eight broods where EPFs occurred, an adjacentmale neighbor was identified as the actual father. Male-likecoloration in females did not reduce the likelihood of havingextrapair young. Females with extrapair young did not receiveless parental care from their mates. All males who obtainedEPFs were mated to fertile females or were feeding offspringat the time they most likely mated with the extrapair female.Our results are consistent with the female control hypothesis,which predicts that females benefit from extrapair copulations(EPCs) and have some control over which males, if any, obtainEPCs. However, we could not reject the alternative hypothesisthat some male neighbors are particularly dominant and aggressiveduring EPC attempts, so females accept these EPCs to minimizecosts.     

Prototype symbolization in hooded crows

The ability in prototype symbolization was studied in four crows trained in matching concept. The experimental approach was characterized by the absence of direct training providing an association between the pictured arrays and Arabic numerals. Experimental sessions were divided into demonstrative and test phases. In the demonstrative phases, the sample and the reinforced stimulus belonged to the same category: if the sample was a pictured array, the reinforced stimulus was also the pictured array, if the sample was a numeral, the reinforced stimulus was likewise a numeral. Matching-to-sample competence was sufficient to perform this task successfully. In case of a correct choice a crow received some mealworms, their number was equal to the number of items in the pictured array or the Arabic numeral. In the test phases, the sample and the comparison stimuli were of different categories. If the sample was a pictured array, the comparison stimuli were numerals; if the sample was a numeral, the comparisons were the pictured arrays. Such tests required the birds to choose a numeric symbol corresponding to the pictured array or to choose the array of pictured items numerically equal to the Arabic symbol. All four crows performed this task successfully. Birds were able to set up a correspondence between the Arabic numeral from 1 to 4 and the number of elements in pictured arrays by way of mental juxtaposition of the earlier received information. Similar experiments showed that crows are likely to be able to perform mental operations with numerals analogous to simple arithmetic addition.     

Genes mapping to boron tolerance QTL in barley identified by suppression subtractive hybridization

Boron tolerance is a quantitative trait controlled by multiple genes. Suppression subtractive hybridization was carried out on root cDNA from bulked boron tolerant and intolerant doubled haploid barley lines grown under moderate boron stress to identify genes associated with boron tolerance. One hundred and eleven clones representing known proteins were found to be up‐regulated in the tolerant bulk upon boron stress. Nine clones were genetically mapped to previously reported boron tolerance QTL. These include a clone identical to the boron transporter gene Bot1 and a clone coding for a bromo‐adjacent homology domain‐containing protein, mapping to the 6H boron tolerance locus and co‐segregating with reduced boron intake in a Clipper × Sahara‐3771 mapping population. A third clone mapping to the 2H QTL region encoding an S‐adenosylmethionine decarboxylase precursor was found to provide tolerance to high boron by heterologous expression. Yeast cells expressing Sahara SAMDC were able to grow on 15 mm boron solid media and maintained cellular boron concentrations at 13% lower than control cells expressing empty vector. The data suggest that an antioxidative response mechanism involving polyamines and the ascorbate–glutathione pathway in Sahara barley may provide an advantage in tolerating high soil concentrations of boron.     

Covert extraterritorial behavior of female hooded warblers

Extraterritorial forays are one specialized tactic that femalesuse to obtain extrapair copulations (EPCs). By radio-trackingfemale hooded warblers (Wilionia citrina) during the breedingseason, we found that females made covert forays onto neighboringterritories. Almost 80% of females made extraterritorial foraysduring their fertile stages, but none visited territories duringthe nonfertile (incubation) stage, which is consistent withthe extraterritorial foray hypothesis. Females that left theirterritories visited from one to four neighboring territories,and they intruded at a rate of 0.6 territories/h. The propensityof females to foray from their territory did not correlate withbody size or age of the social mate. One female that left herterritory obtained an extrapair fertilization. Females may useforays to assess male quality as well as participate in extrapaircopulations. An alternative hypothesis for extra-territorialforays is that females may foray onto neighboring territoriesto obtain food during the energetically stressful period ofegg production. The extraterritorial foray hypothesis and foraginghypothesis may not be mutually exclusive. Females may obtainbenefits of foraging while at the same time assessing malesfor EPCs. Extraterritorial behavior of female birds may be morecommon than previously believed and in many cases may only beruled out through radio-tracking     

Rabies in hooded and striped skunks in Arizona

Arizona is home to four species of skunks, and rabies is enzootic in the region in which their ranges overlap. Examination of state health data from 1985 to 2004 revealed an irregular 4-10 yr periodicity in the number of cases annually, which may be related to past precipitation patterns. The number of rabid skunks peaked during springtime. Locations of rabies epizootics changed over time, but there was no evidence of a large-scale geographic spread. Skunks live-trapped during 1996-2002 had a low prevalence of rabies-virus neutralizing antibodies. This study was the first to document rabies in hooded skunks (Mephitis macroura).     

Spontaneous arthritis in nude rats of Rowett hooded strain

Spontaneous arthritis was found in 19 of 55 Rowett hooded strain rats with rnu gene. Most cases were in the male rnu/rnu (15/19) but a few occurred in the male rnu/+ (3/10) and female rnu/rnu (1/8). The lesions were first noted as reddened swelling due to exudative inflammation of periarticular soft tissues including synovial membranes in the tarsal and/or carpal joints. Most of the affected animals cured leaving slight induration but in a few male rnu/rnu ankylosis with pannus formation and exostosis developed. No sign of mycoplasmal or bacterial infection was noticed in the colony.