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PubMedDate not supplied

Thebaine variations between germplasm sources within one collection of Papaver bracteatum Lindl.

Plants of Papaver bracteatum Lindl. derived from different germplasm sources within one Iranian collection were grown for 18 and 37 weeks in the greenhouse and controlled environment chambers. Gas-chromatographic analyses showed significant differences between thebaine concentrations of root tissue for 18-week-old plants, but not for 37-week-old plants. The two age groups did not differ in thebaine yield per unit of dry weight of root tissue. However, due to more profuse root growth, the total yield of thebaine from roots of the older plants was about four times that of the younger plants. Shoot thebaine concentrations differed significantly for 18- and 37-week-old plants. The over-all mean thebaine concentration for shoots of older plants was nearly twice that of younger plants. The variation in thebaine concentrations in these plants suggested genetic differences between the germplasm sources. Thus, domestication of P. bracteatum will require selection of germplasm from within and between collections, for plants of the greatest economic potential.

Iran↗
PubMed1988

[Genetic aspects of systematic mineralization disorders].

Forced selection for high daily gains and meatiness induced biological maladaptations of genetical-hormonal origin. They manifest themselves not only by well-known myopathies and predispositions to stress, but also in the so-called leg weakness of pigs, in dyschondroplasias of broilers; similar "correlated" effects are observed even in dogs and laboratory animals. As far as bones, cartilages and joints are concerned by these deficiencies in mineralization and synthesis of fibrous structures, the terms "osteochondrosis" or "osteochondropathies" were introduced recently. Manifestations and severeness of this phenomenon--induced by antagonistic selection criteria--species not always directly comparable from species to species or even from breed to breed within species. This variability can be interpreted as an indication for the compound effects of heredity and environment. Even in pure breeds like German landrace and Piétrain and even under identical rearing and fattening conditions a significant individuality was found with respect to utilization of minerals; this is documented by different biomechanical strength and mineralization of bones and cartilaginous structures in these animals and by estimates of heritability for these traits, which range slightly higher than those estimated for "leg weakness". Selective measures, therefore, against the antagonisms mentioned could be feasible. On the other hand these investigations revealed that at least in some contingents of domestic animals a biological borderline was trespassed when selecting rigorously for a few economically important traits.

Animals↗
PubMed1983

Adipose tissue cellularity and histochemistry in fetal swine as affected by genetic selection for high or low backfat.

Adipose tissue development was studied histochemically and histologically in fetuses from lean and obese sows. At 110 days of gestation, fetuses were removed from Ossabaw (obese-feral) sows and from sows selected for high backfat (obese-domestic) and for low backfat (lean) thickness. Body weights were similar for lean (916 +/- 225 g) and obese (822 +/- 167 g) domestic fetuses, whereas obese feral fetuses were smaller (631 +/- 70 g). Histological and histochemical analysis was conducted on subcutaneous tissue from over the shoulder. Staining for lipid-containing fat cells indicated similar concentrations of fat cells throughout the depth of the subcutaneous tissue from obese (domestic and feral) and lean fetuses. Adipocytes from obese fetuses were slightly larger (domestic 23 +/- 0.22 microns, feral 21.8 +/- 0.26 microns) than cells from lean fetuses (20.7 +/- 0.42 microns). The percentage glycogen positive (PAS) adipocytes was low and similar from all three fetal strains. Less than 10% of adipocytes from lean and obese domestic fetuses were esterase-positive, whereas 42% of adipocytes from obese feral fetuses were esterase-positive. All adipocytes from obese fetuses (domestic and feral) were lipoprotein lipase (LPL)-positive whereas all cells from lean fetuses were negative for LPL activity. Therefore, cellular and metabolic differences exist in adipose tissue of lean and obese pigs during the prenatal period of growth and development.

Adipose Tissue↗
PubMed1992

International comparisons: selected mental health data.

The data set from the Organization for Economic Cooperation and Development (OECD) was explored to investigate the relationship of gross domestic product (which provides an indication of the wealth of a country) and the provision of psychiatric services (specifically inpatient psychiatric services) in selected OECD countries. Gross domestic product per capita correlated .84 with expenditure per capita on psychiatric hospitals but r was zero between number of beds per 1000 population and length of stay.

Cross-Cultural Comparison↗
PubMedDate not supplied

A comparison of genetic variability in strains of Japanese quail selected for heavy body weight.

Electrophoretic analyses of body tissues from three strains of Japanese quail from the Quail Genetic Stock Centre at the University of British Columbia, two selected for heavy body weight and one randombred, were carried out to determine whether genetic variations in selected strains were different from randombred strains. In addition, the data were also compared with those obtained from domestic and wild populations in Japan. The proportion of polymorphic loci was higher in the heavy strains than in the randombred strain. The selected strains also differed from the randombred strain in the allelic frequencies of liver esterase and phosphogluconate dehydrogenase. While the randombred strain was genetically similar to the domestic strains in Japan, the two selected strains were different from each other and from the domestic strains in Japan. This indicates that (1) polymorphic loci have adaptive importance, and (2) heavy body weight can be achieved by separate genetic mechanisms. A previously unreported allele that affects the migration pattern of muscle adenylate kinase was also discovered in one of the selected strains.

Animals↗
PubMed1981

Host feeding profiles of Rhodnius pallescens (Hemiptera: Reduviidae) in rural villages of Central Panama.

Rhodnius pallescens, reported to be the principal vector of Chagas' disease in central Panama, has been shown to feed on opossums, anteaters, sloths, rodents, birds and, rarely, lizards in sylvatic habitats in this country; however, the extent of its anthropophagic affinities in rural areas has never been determined. The host selections of 1,340 R. pallescens from domestic and peridomestic habitats of three Panamanian villages were determined by microcapillary precipitin tests. Slightly more than half of the triatomines collected in houses and nearby palm trees and bird nests had fed on humans. Opossums, which are important reservoirs of Trypanosoma cruzi in Panama, were the second most frequently selected host. The importance for the transmission of Chagas' disease to humans of the close relationship between the principal vector and reservoir in sylvatic and peridomestic environments and the anthropophagy of the former is discussed. Pigeons and chickens were the dominant bloodmeal sources of triatomines collected in their respective shelters. The roof rat, Rattus rattus, was the third most common mammalian host, and may represent an ancillary reservoir in the transmission of Chagas' diseases in rural areas of Panama.

Animals↗
PubMed2006

Gelatinization temperature of rice explained by polymorphisms in starch synthase.

The cooking quality of rice is associated with the starch gelatinization temperature (GT). Rice genotypes with low GT have probably been selected for their cooking quality by humans during domestication. We now report polymorphisms in starch synthase IIa (SSIIa) that explain the variation in rice starch GT. Sequence analysis of the eight exons of SSIIa identified significant polymorphism in only exon 8. These single nucleotide polymorphisms (SNPs) were determined in 70 diverse genotypes of rice. Two SNPs could classify all 70 genotypes into either high GT or low GT types which differed in GT by 8 degrees C. 'A' rather than 'G' at base 2412 determined whether a methionine or valine was present at the corresponding amino acid residue in SSIIa, whilst two adjacent SNPs at bases 2543 and 2544 coded for either leucine (GC) or phenylalanine (TT). Rice varieties with high GT starch had a combination of valine and leucine at these residues. In contrast, rice varieties with low GT starch had a combination of either methionine and leucine or valine and phenylalanine at these same residues. At least two distinct polymorphisms have apparently been selected for their desirable cooking qualities in the domestication of rice.

DNA, Plant↗
PubMed1997

[Domestication-related behavior in sheep].

The motivational nature of domestication-related behavior, as well as its formation and variation at the ontogenetic, population, and breed levels were studied. Food motivation participated in the environmental regulation of sheep defensive reactions to humans: an increase in motivation decreased the strength of defensive behavior, and vice versa. Defensive behavior became weaker with age, with the rate of decrease higher in sheep with high food motivation. Comparison of 11 breeds revealed that the polymorphism of domestication-related behavior was breed-specific. In low-specialized breeds, the "wild" class prevailed (77.0-94.7%); it was characterized by a pronounced defensive behavior. In commercial breeds, the range of variation was broader, with a higher proportion of "domestication" classes. In Ost-Friesian sheep, this proportion was 86.0%. It is suggested that the polymorphism of domestication-related behavior was formed in commercial breeds as a result of natural selection for adaptation to breeding-related stresses and artificial selection for productivity.

Animals↗
PubMed1990

Analysis of the inheritance, selection and evolution of growth trajectories.

We present methods for estimating the parameters of inheritance and selection that appear in a quantitative genetic model for the evolution growth trajectories and other "infinite-dimensional" traits that we recently introduced. Two methods for estimating the additive genetic covariance function are developed, a "full" model that fully fits the data and a "reduced" model that generates a smoothed estimate consistent with the sampling errors in the data. By decomposing the covariance function into its eigenvalues and eigenfunctions, it is possible to identify potential evolutionary changes in the population's mean growth trajectory for which there is (and those for which there is not) genetic variation. Algorithms for estimating these quantities, their confidence intervals, and for testing hypotheses about them are developed. These techniques are illustrated by an analysis of early growth in mice. Compatible methods for estimating the selection gradient function acting on growth trajectories in natural or domesticated populations are presented. We show how the estimates for the additive genetic covariance function and the selection gradient function can be used to predict the evolutionary change in a population's mean growth trajectory.

Animals↗
PubMed1983

Increase in oxygen consumption induced by selective spinal cord cooling in the exercising pigeon.

Six domestic pigeons with chronically implanted spinal thermodes were exercised on a treadmill at neutral ambient temperature. During the exercise the spinal cord was cooled to 34.7 +/- 0.4 degrees C (mean +/- S.E.M.). Oxygen consumption of the pigeons increased from 28.3 +/- 2.1 to 61.2 +/- 3.7 ml X min-1 X kg-1 due to exercise per se, and superimposed cooling of the spinal cord during exercise induced an additional increase in oxygen consumption to 84.9 +/- 4.5 ml X min-1 X kg-1. The result demonstrates that cooling of the spinal cord elicits shivering in exercising pigeons at thermoneutral conditions.

Animals↗
PubMed2007

Using variable rate models to identify genes under selection in sequence pairs: their validity and limitations for EST sequences.

Using likelihood-based variable selection models, we determined if positive selection was acting on 523 EST sequence pairs from two lineages of sunflower and lettuce. Variable rate models are generally not used for comparisons of sequence pairs due to the limited information and the inaccuracy of estimates of specific substitution rates. However, previous studies have shown that the likelihood ratio test (LRT) is reliable for detecting positive selection, even with low numbers of sequences. These analyses identified 56 genes that show a signature of selection, of which 75% were not identified by simpler models that average selection across codons. Subsequent mapping studies in sunflower show four of five of the positively selected genes identified by these methods mapped to domestication QTLs. We discuss the validity and limitations of using variable rate models for comparisons of sequence pairs, as well as the limitations of using ESTs for identification of positively selected genes.

Base Pairing↗
PubMed1995

Domestication and plasticity of brain organization in mallards (Anas platyrhynchos).

The sizes and histological differentiation of structures in the central nervous system of wild and domestic ducks were compared using allometric methods. Whole brain volume is 14.3% less in domestic ducks than in wild birds, and the size of certain brain structures is more variable in domestic ducks than in the wild birds. These findings are consistent with results of studies in other domestic birds and in domestic mammals. Although the brain subdivision volumes are not reduced to the same extent, the relative composition of the brain is maintained in domestic ducks. The overall reduction in rhombencephalic parts of the brain (16.3%) is greater than that in the prosencephalon (13.5%). Within sensory centers the nuclei of the trigeminal system undergo the most marked decrease (21.3%). Optic (13.3%) and limbic (11.1%) structures are less reduced, and the olfactory regions do not show any differences in volume compared to these regions in wild mallards. Reductions in the volumes of brain structures in domesticated animals have been thought to be processes of functional adaptation controlled by artificial selection. Our observations are discussed with regard to hypotheses about trends in domestication and evolutionary plasticity.

Animals↗
PubMed1997

Hereditary polioencephalomyelopathy of the Australian cattle dog.

A vacuolar degeneration affecting primarily the gray matter in the central nervous system (CNS) of young Australian Cattle Dogs is described. An initial presentation of seizures was followed by a progressive spastic tetraparesis. Grossly evident bilateral and symmetrical foci of malacia were in the nuclei of the cerebellum and brain stem and the gray matter of the spinal cord. Microscopically, vacuolation of glial cells, dilation of the myelin sheaths and reactive astrocytosis characterized mild CNS changes. More advanced lesions displayed progressive dissolution of the neuropil, prominent vacuolation of reactive astrocytes, numerous glial fibrillary acidic protein-positive coiled astrocytic processes, neuronal vacuolation and loss with relative sparing of large neurons. Ultrastructurally marked mitochondrial accumulation and swelling were seen in astrocytes. In the appendicular muscles, changes interpreted as long-term denervation atrophy accompanied by widespread expression of the neonatal isoform of myosin were observed. The character of the neurological sings, the nature and the distribution of the lesions within the neuroaxis have not been reported in domestic animals. An inherited biochemical defect, possibly mitochondrial, is proposed as the cause. Selected conditions with a bilateral and symmetrical distribution affecting the gray matter of domestic animals are summarized.

Animals↗
PubMed1998

[Seroepidemiology of Toxoplasma gondii infection among dogs in Taipei, Taiwan].

Seroprevalence of toxoplasmosis in dogs was investigated in Taipei from July 1995 to June 1996 by the latex agglutination assay. A total of 289 serum samples were taken from stray and domestic dogs as well as from dogs in randomly selected animal hospitals and pet stores. The overall seroprevalence among all dogs was 24.6% (71/289). With regard to the source of the dogs, the seropositivity was 15.4% (10/65) for dogs in animal hospitals, 16.3% (7/43) for dogs in pet stores, 15.5% (11/71) for domestic dogs and 39.1% (43/110) for stray dogs. The seropositivity of stray dogs was significantly higher than that of the domestic dogs (P < 0.05). However, there was no significant difference among the randomly selected places or dog strains (P > 0.05).

Animals↗
PubMed2004

A genetic variation map for chicken with 2.8 million single-nucleotide polymorphisms.

We describe a genetic variation map for the chicken genome containing 2.8 million single-nucleotide polymorphisms (SNPs). This map is based on a comparison of the sequences of three domestic chicken breeds (a broiler, a layer and a Chinese silkie) with that of their wild ancestor, red jungle fowl. Subsequent experiments indicate that at least 90% of the variant sites are true SNPs, and at least 70% are common SNPs that segregate in many domestic breeds. Mean nucleotide diversity is about five SNPs per kilobase for almost every possible comparison between red jungle fowl and domestic lines, between two different domestic lines, and within domestic lines--in contrast to the notion that domestic animals are highly inbred relative to their wild ancestors. In fact, most of the SNPs originated before domestication, and there is little evidence of selective sweeps for adaptive alleles on length scales greater than 100 kilobases.

Alleles↗
PubMed1996

Excessive stimulation of serotonin2 (5-HT2) receptors during late development of chicken embryos causes decreased embryonic motility, interferes with hatching, and induces herniated umbilici.

The existence and functional significance of 5-HT2 receptors in chicken embryos was studied by injecting the selective agonist dimethoxyiodophenylaminopropane (DOI), alone or in conjunction with the selective 5-HT2 antagonist ritanserin (RIT), into domestic chicken eggs with embryos of varying ages. DOI caused dose-dependent reductions in hatchability and herniated umbilici in hatchlings. These effects were observed after injection early, mid, or late during embryonic development, with evidence of the toxic effects of DOI being greater in older embryos, probably due to 5-HT2 receptor activation late in development, even after injecting DOI as early as on day 3 of embryogenesis. This is based upon the fact that embryos in eggs injected with DOI early continued to develop apparently normally, failing to hatch, often after pipping their shells. Additionally, those that hatched often did so with herniated umbilici, as did late-exposed embryos, indicating that DOI's effects upon this organ were most likely mediated during the prehatching period (i.e., days 18-20). The agonist's selectivity was confirmed by the capacity of RIT to dose dependently block both of these toxic effects of DOI. Reduced embryonic motility monitored on day 19, after injection of DOI on the evening of day 18, suggests that excessive activation of 5-HT2 receptors late during development of this species interferes with some normal embryonic behaviors and physiological changes necessary for inducing and/or maintaining the hatching process.

Animals↗
PubMed1981

Effects of domestication on production and perception of mallard maternal alarm calls: developmental lag in behavioral arousal.

The process of domestication involves intense inbreeding. Field and laboratory studies were conducted to assess the effects of such intense genetic selection on the production and perception of the maternal alarm calls of domestic (Peking) and wild mallard ducks (Anas platyrhynchos). With respect to production, the calls of wild and domestic ducks were comparable in four acoustic features and differed only slightly on two features. With respect to perception, the calls of wild and domestic hens were equally effective in promoting behavioral inhibition in wild and domestic ducklings. Although these data revealed little or no effect of domestication on the structure and function of the maternal alarm call, an unexpected effect was found regarding the domestic ducklings' behavior. Specifically, Pekings showed a greater level of behavioral inhibition than did mallards at 24 hr of age. Further experiments indicated that the differential level of inhibition in the wild and domestic birds reflects a developmental lag in arousal consequent to domestication: 72-hr-old Peking ducklings are behaviorally more aroused than 24-hr-old Peking ducklings and are similar to 24-hr-old mallard ducklings in that respect. This appears to be the first demonstration of behavioral heterochrony, which is believed to be an important mechanism of behavioral evolution.

Animals↗