Hormonally regulated programmed cell death in barley aleurone cells

Cell death was studied in barley (cv Himalaya) aleurone cells treated with abscisic acid and gibberellin. Aleurone protoplasts incubated in abscisic acid remained viable in culture for at least 3 weeks, but exposure to gibberellin initiated a series of events that resulted in death. Between 4 and 8 days after incubation in gibberellin, >70% of all protoplasts died. Death, which occurred after cells became highly vacuolated, was manifest by an abrupt loss of plasma membrane integrity followed by rapid shrinkage of the cell corpse. Hydrolysis of DNA began before death and occurred as protoplasts ceased production of alpha-amylase. DNA degradation did not result in the accumulation of discrete low molecular weight fragments. DNA degradation and cell death were prevented by LY83583, an inhibitor of gibberellin signaling in barley aleurone. We conclude that cell death in aleurone cells is hormonally regulated and is the final step of a developmental program that promotes successful seedling establishment.     

Creation of a collection of morphological insertional mutants of Arabidopsis thaliana

A collection of transgenic Arabidopsis thaliana plants has been obtained by Agrobacterium-mediated transformation. The genomes of the transgenic plants contain insertions of T-DNA of the vector plasmids pLD3 or pPCVRN4. Genes bearing T-DNA insertions were shown to constitute 12-18% of the total number of A. thaliana genes. Seventy-five lines have been chosen from the collection and subjected to genetic and molecular-genetic analysis. Of these, 5 were dominant mutants, and 70, recessive insertion mutants with various morphological defects. Identification of mutant phenotypes and genetic characterization of the transgenic lines have been performed with the use of nutrient media supplemented with exogenous hormones, which revealed five recessive lethal mutants and one dominant sterile mutant.     

Functional reserves and adaptive potential of various levels of habitual motor activity

On the basis of longitudinal studies in children of older preschool and early school-age boys and girls with low, medium and high habitual physical activity (NAPA, SPDA, VPDA) identified the basic characteristics of the cardiovascular system, physical capacity and the degree of tension of regulatory mechanisms at rest and during functional loading. Analysis of the statistical distribution of the trait given chi2 and lambda criteria and average data of various functional indicators in the total sample identified a fairly wide area and the divergent levels of physiological individuality in a healthy population and the desirability of allocating the three typological groups--functional types (FT-1 - NAPA, the FT-2 - SPDA, FT-3 - VPDA). Model parameters are allocated first and second order for each CFT, as well as performance tests of the third order, describing the current functional status. Determination of the physiological features of the FT-1 FT-2 FT-3 with the establishment of their functional reserves and adaptive capacity makes it possible to identify the different strategies of interaction with the environment, evaluate their advantages and disadvantages and a more grounded approach to the problem of optimization of physical condition and prenosological diagnosis.     

The concept of typological variability of physiological individuality: III. Psychophysiological characteristics of functional types differing in habitual physical activity

Results of longitudinal studies were used to estimate the psychophysiological characteristics of preschool and young school children and young adults of both sexes belonging to functional types (FTs) with low, medium, and high habitual physical activity (HPA) levels (FT-1, LHPA; FT-2, MHPA, and FT-3, HHPA, respectively). Statistical analysis of the distributions of averaged psychophysiological parameters in the total sample with the use of the χ² and λ tests showed wide quantitative and qualitative ranges of psychophysiological individuality in a healthy population and demonstrated that it is reasonable to distinguish three typological groups (FT-1, FT-2, and FT-3). Typical first- and second-order parameters, as well as the results of third-order tests characterizing the current state, were determined for each FT. Determination of the psychophysiological characteristics of FT-1, FT-2, and FT-3 and their prevailing behavioral tendencies makes it possible to differentiate between strategies of organism-environment interaction and estimate their advantages and disadvantages.     

Contractile behavior of the forelimb digital flexors during steady-state locomotion in horses (Equus caballus): an initial test of muscle architectural hypotheses about in vivo function

The forelimb digital flexors of the horse display remarkable diversity in muscle architecture despite each muscle-tendon unit having a similar mechanical advantage across the fetlock joint. We focus on two distinct muscles of the digital flexor system: short compartment deep digital flexor (DDF(sc)) and the superficial digital flexor (SDF). The objectives were to investigate force-length behavior and work performance of these two muscles in vivo during locomotion, and to determine how muscle architecture contributes to in vivo function in this system. We directly recorded muscle force (via tendon strain gauges) and muscle fascicle length (via sonomicrometry crystals) as horses walked (1.7 m s(-1)), trotted (4.1 m s(-1)) and cantered (7.0 m s(-1)) on a motorized treadmill. Over the range of gaits and speeds, DDF(sc) fascicles shortened while producing relatively low force, generating modest positive net work. In contrast, SDF fascicles initially shortened, then lengthened while producing high force, resulting in substantial negative net work. These findings suggest the long fibered, unipennate DDF(sc) supplements mechanical work during running, whereas the short fibered, multipennate SDF is specialized for economical high force and enhanced elastic energy storage. Apparent in vivo functions match well with the distinct architectural features of each muscle.     

Latitudinal clines in body size,but not in thermal tolerance or heat‐shock cognate 70 (HSC70), in the highly‐dispersing intertidal gastropod Littorina keenae (Gastropoda: Littorinidae)

Natural populations of widely‐distributed animals often exhibit clinal variation in phenotypic traits or in allele frequencies of a particular gene over their geographical range. A planktotrophic intertidal snail, Littorina keenae is broadly distributed along the north‐eastern Pacific coast through a large latitudinal range (24°50′N–43°18′N). We tested for latitudinal clines in two complex phenotypic traits – thermal tolerance and body size – and one single locus trait – heat shock cognate 70 (HSC70) – in L. keenae along almost its entire geographical range. We found only weak evidence for a latitudinal cline in the thermal tolerance and no evidence for a cline in allele frequencies at HSC70. However, as predicted by Bergmann's rule, we detected a strong latitudinal cline that accounted for 60% of the variance in body size (R² = 0.598; P < 0.001). In contrast, body size did not significantly affect thermal tolerance. HSC70 showed no genetic differentiation among the populations, supporting our previous mitochondrial gene‐based estimate of high gene flow during this snail's free‐swimming larval stage. Given that L. keenae experiences panmixia along its species range, the observed size cline may be partially or entirely caused by a phenotypically plastic response to local thermal environments rather than by genetic divergence in body size among populations in response to locally optimizing natural selection. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100 , 494–505.     

Identification of the gene whose mutation leads to the morphological changes in the hypocotyl of <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis>

The results of genetic and molecular genetic analysis of line 176 of Arabidopsis thaliana with reduced hypocotyls obtained from a previously developed collection of insertion mutants, are presented. The examined mutation proved to be recessive and based on a single insertion of the T-DNA vector pLD3 into the A. thaliana genome. Computer-aided analysis of the amplified in TAIL-RCR DNA region adjacent to the left border of the insertion revealed a putative site of T-DNA insertion, the 2.5-kb At2g09920 gene located in the long arm of chromosome 2, near the centromere.Translated from Genetika, Vol. 41, No. 2, 2005, pp. 166–170.Original Russian Text Copyright © 2005 by Ogarkova, Tomilov, Tomilova, Pogorelko, Tarasov.     

Identification of the gene whose mutation leads to hypocoptyl tropism in <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis>

Genetic and molecular analysis of a mutant of Arabidopsis thaliana with bended hypocoptyl from a previously obtained collection of insertion mutants is presented. The examined mutation was shown to be recessive and based on a single insertion of pLD3 vector T-region into the A. thaliana genome. Computer-aided TAIL-PCR analysis of a DNA region adjacent to the left border of the insertion revealed a putative site of T-DNA insertion, the 609-bp At1g15760 gene from chromosome 1 represented by a single exon.Translated from Genetika, Vol. 41, No. 3, 2005, pp. 427–429.Original Russian Text Copyright © 2005 by Ogarkova, Tomilov, Tomilova, Tarasov.     

Demographic Data of a Population of Insured Swedish Dogs Measured in a Questionnaire Study

Dogs, in the age range 1–3 years old, were randomly selected from the largest animal insurance database in Sweden for inclusion in the study. The study was performed in 1997, and a total of 680 dog owners were selected for the study. A total of 461 dog owners completed the survey, at an overall response rate of 68%. Data was compared to a recent gallup performed on a sample of all dogs in Sweden. The demographic statistics of the insured dog population were in many aspects similar to the total dog population of Sweden. Typical for both insured dogs and the total population of dogs were a low proportion of neutered dogs, that many dogs were bought at an early age, that many dogs were in contact with a "breeder" when sold, and a similar profile of health status. However, "dog breeders" seemed to have their dogs insured to a higher extent than the general dog owner. It was concluded that as the populations were alike in many respects, it is reasonable to use the insurance database for epidemiological studies on diet and exercise in Swedish dogs.