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PubMed1991

[Occurrence of staphylococcal species in clinically healthy domestic animals].

The incidence of staphylococcus species in healthy animals was investigated in young and adult individuals of cattle, in pigs and in domestic fowl, using the method of selective isolation of strains. A total of 6066 samples was examined; 4567 strains were revealed and they included all known species, except Staphylococcus caseolyticus, S. saccharolyticus, S. schleiferi and S. lugdunensis. 3.8% of strains failed to be identified with any species. The test samples were taken from slaughtered animals, only in calves intravital smears of tonsils were examined. The species most frequently isolated from the tonsil tissue in adult cattle were as follows: S. aureus (19.9%), S. saprophyticus (12.4%), S. hyicus (8.8%) and S. hominis (8.6%). The following species were isolated from the lung tissue: S. saprophyticus (28.8%), S. cohnii (10.6%) and S. epidermidis (10.2%); from the mammary gland parenchyma these were the species S. saprophyticus (17.4%), S. xylosus (13.1%) and S. epidermidis (10%). In the tonsil tissue of pigs the percent proportions of S. aureus and S. hyicus were 44.5% and 31.8%, respectively; the most frequent species detected from the lungs were S. aureus (20.6%), S. saprophyticus (12.3%), S. hyicus (12.1%) and S. epidermidis (11.5%). In domestic fowl the most frequently occurring species were S. epidermidis (23.7%), S. gallinarum (16.5%) and S. aureus (15.4%). In calves the incidence of S. xylosus (37%), S. saprophyticus (19.2%) and S. cohnii (15.2%) was found to be highest. The indicence of the other staphylococcus species in all test animals can be expressed by low percentages.

Animals↗
PubMed1998

Physiological responses of hens divergently selected on the number of chicks obtained from a single insemination.

A series of experiments was conducted in domestic fowl to investigate the consequences of five generations of divergent selection for increased (L+) or decreased (L-) numbers of hatched chicks. After artificial insemination with pooled ejaculates within the same line (L+ males x L+ hens or L- males x L- hens), significant differences were observed between L+ and L- hens for mean fertility rates (L+ 94.8%, L- 70.2%, P < 0.0001) and for effective and maximum duration of fertility (P < 0.00001). A comparison of the overall laying performance and shell quality between the two selected lines showed that L- hens laid fewer eggs than L+ hens (P < 0.00001) and L- eggs had poorer shell quality (shell breaking strength) than L+ eggs (P < 0.00001). These observations were associated with significantly higher percentages of early embryo death in eggs from L- hens compared with L+ hens. Another series of experiments revealed the presence of larger initial populations of spermatozoa in the sperm storage tubules as well as in the perivitelline layer of eggs from L+ hens. The populations of spermatozoa in the sperm storage tubules of commercial laying hens inseminated with pooled semen samples from L+ males was compared with those in hens inseminated with samples from L- males to determine whether the variations in oviductal sperm storage between the two lines were male dependent. No significant differences between the populations of spermatozoa present in the sperm storage tubules of either group of hens could be detected at any of the intervals examined after insemination (days 1, 3 and 10). Finally, an experiment conducted on hens originating from the two selected lines indicated that the utero-vaginal junction of L+ hens contained significantly more sperm storage tubules compared with L- hens (P < 0.01). It is concluded that selection based on overall reproductive performance modifies the number of eggs capable of developing viable embryos and also influences the efficacy of initial sperm storage by increasing or altering the population of sperm storage tubules located in the utero-vaginal junction. Such changes have major consequences on the duration of the fertile period, which in avian species is directly dependent on both the actual population of spermatozoa stored in the oviduct and on their rate of release from the storage sites.

Animals↗
PubMed2006

Neurodegenerative diseases in domestic animals: a comparative review.

Neurodegenerative diseases are characterised by selective damage to specific neurons in the nervous system. Interest in such diseases in humans has resulted in considerable progress in the molecular understanding of these disorders in recent decades. Numerous neurodegenerative diseases have also been described in domestic animals but relatively little molecular work has been reported. In the present review, we have classified neurodegenerative disease according to neuroanatomical criteria. We have established two large groups, based on whether the neuronal cell body or its axon was primarily affected. Conditions such as motor neuron diseases, cerebellar degenerations and neuroaxonal dystrophies are discussed in terms of their clinical and neuropathological features. In the most studied disorders, we also present what is known about underlying pathomechanisms, and compare them with their human counterparts. The purpose of this review is to re-kindle interest in this group of diseases and to encourage veterinary researchers to investigate molecular mechanisms by taking advantage of current diagnostic tools.

Animal Diseases↗
PubMed2003

Functional trade-offs in the limb muscles of dogs selected for running vs. fighting.

The physical demands of rapid and economical running differ from those of physical fighting such that functional trade-offs may prevent simultaneous evolution of optimal performance in both behaviours. Here we test three hypotheses of functional trade-off by measuring determinants of limb musculoskeletal function in two breeds of domestic dogs that have undergone intense artificial selection for running (Greyhound) or fighting performance (Pit Bull). We found that Greyhounds differ from Pit Bulls in having relatively less muscle mass distally in their limbs, weaker muscles in their forelimbs than their hindlimbs, and a much greater capacity for elastic storage in the in-series tendons of the extensor muscles of their ankle joints. These observations are consistent with the hypothesis that specialization for rapid or economical running can limit fighting performance and vice versa. We suggest that functional trade-offs that prevent simultaneous evolution of optimal performance in both locomotor and fighting abilities are widespread taxonomically.

Agonistic Behavior↗
PubMed1992

Exonic polymorphism vs intronic simple repeat hypervariability in MHC-DRB genes.

Gene products encoded by the major histocompatibility complex often exhibit a high degree of polymorphism. In humans the HLA-DR polymorphism is due to more than 50 alleles with varying exon 2 sequences. Each group of DRB alleles contains a certain form of the basic simple repeat motif (gt)n(ga)m in intron 2. Identical alleles can be differentiated on the basis of the hypervariable repeat. In this study focused on cattle (Bos taurus) we identified different Bota-DRB alleles in a limited survey by amplification via polymerase chain reaction and sequencing. In addition DRB exon 2 sequences were also obtained from eight additional hoofed animal species (seven horned artiodactyls and one pig) revealing artiodactyl-specific polymorphic and nonpolymorphic substitutions. In the genus Bos the intronic simple repeat variability was compared with exonic DRB polymorphism. As in humans all Bota-DRB exons were always associated with specifically organized basic simple repeat structures. Yet the extent of simple repeat variability was lower in cattle compared to humans. Selective breeding in the process of domestication might be responsible for the diminished intronic hypervariability. Nevertheless, the hypermutable simple repeat sequences have been preserved in the same position and with the same principal structure for at least 70 x 10(6) years of evolution. Unexpectedly, the rate of intronic simple repeat and exonic changes appear quite similar.

Alleles↗
PubMed1981

Genetic influences on locomotor activity in 11-day-old housemice.

An 8 X 8 diallel analysis of locomotor activity related to nest return in mice just prior to eye opening indicated a pattern of dominance toward high activity, with little additive genetic variance. Groups of laboratory-reared wild mice did not differ from each other or from the diallel mean, suggesting little relaxation of selection toward rapid nest return during domestication. In contrast to the nest return situation, an eight-strain triple test-cross analysis of locomotion in a test environment unlikely to be encountered by 11-day-old mice indicated only additive genetic variance, with no evidence of dominance for increased activity. When measured in an ecologically relevant environment, the nature of genetic variation appears to change with age in a manner concordant with what one would intuitively assume to be adaptive behavior at each stage of development.

Aging↗
PubMed1985

A simple method for the establishment of tissue culture melanocytes from regenerating fowl feathers.

A quick and simple method for the establishment of tissue cultures of nonembryonic domestic fowl melanocytes was desired. The selected source of these cells was the 14-d-old regenerating feather. Three procedures were compared on the basis of the yield and purity of melanocytes. For the first method, 2 mm of the proximal end of the feather was cut off under sterile conditions and placed immediately in Hanks' balanced salt solution (BSS) containing antibiotics. The feather was split longitudinally and the pulp removed. The tissue was placed pulp side down in several drops of Ham's F12 medium containing 2.5 micrograms/ml Fungizone, 50 micrograms/ml gentamicin, 100 micrograms/ml streptomycin, 100 micrograms/ml penicillin, and 10% fetal bovine serum. After 2 h at 37 degrees C, the tissue was attached to the dish and new medium was added and changed every 3 d thereafter. Cells migrated from the tissue starting on Day 2 and the tissue was removed on Day 5. Large dendritic peripheral cells and small round central cells were seen. Approximately 6.5 X 10(4) cells were present on Day 10 and 8 X 10(4) cells were counted on Day 20. By Day 30, the pigmented melanocytes were large, flat, dendritic cells. Electron microscopy and the use of the dopa reaction indicated that the population of cells was almost entirely melanocytes. The second method used was similar to the first, the only difference being that the feather sheath was also removed and thus only the collar of cells remained. The third method tried was similar to the second with the difference that the collar of cells was gently agitated with 0.25% trypsin for 5, 10, and 20-min intervals at 37 degrees C. The trypsin supernatant fluid was removed by gentle centrifugation and medium plus fetal bovine serum was added to stop tryptic action. The second method showed no advantage over the first. The purity and yield of melanocytes in the third method were lower than in either of the previous two methods. The number of cells desired can be controlled by varying the number of the feather pieces used per culture.

Animals↗
PubMed2004

Excitotoxic lesions of the medial striatum delay extinction of a reinforcement color discrimination operant task in domestic chicks; a functional role of reward anticipation.

To reveal the functional roles of the striatum, we examined the effects of excitotoxic lesions to the bilateral medial striatum (mSt) and nucleus accumbens (Ac) in a food reinforcement color discrimination operant task. With a food reward as reinforcement, 1-week-old domestic chicks were trained to peck selectively at red and yellow beads (S+) and not to peck at a blue bead (S-). Those chicks then received either lesions or sham operations and were tested in extinction training sessions, during which yellow turned out to be nonrewarding (S-), whereas red and blue remained unchanged. To further examine the effects on postoperant noninstrumental aspects of behavior, we also measured the "waiting time", during which chicks stayed at the empty feeder after pecking at yellow. Although the lesioned chicks showed significantly higher error rates in the nonrewarding yellow trials, their postoperant waiting time gradually decreased similarly to the sham controls. Furthermore, the lesioned chicks waited significantly longer than the controls, even from the first extinction block. In the blue trials, both lesioned and sham chicks consistently refrained from pecking, indicating that the delayed extinction was not due to a general disinhibition of pecking. Similarly, no effects were found in the novel training sessions, suggesting that the lesions had selective effects on the extinction of a learned operant. These results suggest that a neural representation of memory-based reward anticipation in the mSt/Ac could contribute to the anticipation error required for extinction.

Analysis of Variance↗
PubMed2005

Investigation on dynamic changes of photosynthetic characteristics of 10 wheat (Triticum aestivum L.) genotypes during two vegetative-growth stages at water deficits.

Drought is a worldwide problem, seriously influencing plant (crop) productivity. Wheat is a stable food for 35% of the world population, and moreover, about 60% of land area on the globe belongs to arid and semiarid zone. Wheat drought resistance is a multi-gene controlling quantitative character and wheat final production in field is realized mainly by physiological regulation under the condition of multi-environmental factor interaction. Exploring drought resistance physiological mechanisms for different wheat genotypes is of importance to finding new drought resistance gene resources and conventional breeding, and the basis for wheat drought resistance biotechnological breeding and platform. Photosynthesis is the main component for physiological machinery of wheat assimilates conversion and wheat production. Investigation on photosynthetic characteristics of different wheat genotypes at soil water deficits also has other implications for refine physiological regulation of photosynthesis in fields and field management of crops in arid and semiarid areas. By pot-cultivating experiments, investigation of photosynthesis for 10 wheat genotypes at seedling stage and tillering stage at soil water deficits (75%FC, 55%FC and 45%FC, respectively) was conducted. The main results were as followed: developmental stages influenced wheat photosynthesis greatly and tillering stage played more roles; there were significant difference in the main photosynthetic parameters, photosynthesis rate (Photo), stomatal conductance (Cond) and transpiration rate (Tr), among 10 wheat genotypes; general photosynthesis and drought resistance in different wheat genotypes was related much to their domesticated origin soil water environment and selected generations and there was a photosynthetic threshold effect in terms of different wheat genotypes at soil water deficits.

Antioxidants↗
PubMed2002

QTL analysis of a red junglefowl x White Leghorn intercross reveals trade-off in resource allocation between behavior and production traits.

Behaviors with high energetic costs may decrease in frequency in domestic animals as a response to selection for increased production. The aim of this study was to quantify production traits, foraging behavior, and social motivation in F2 progeny from a White Leghorn x red junglefowl intercross (n = 751-1046) and to perform QTL analyses on the behavioral traits. A foraging-social maze was used for behavioral testing, which consisted of four identical arms and a central box. In two arms there was ad libitum access to the birds' usual food, and in the other two there was novel food (sunflower seeds) mixed with cat litter. In one arm with each of the two food sources, social stimuli were simulated by the presence of a mirror. Each bird could therefore feed on novel or well known food either alone or in the perceived company of a conspecific. Egg production, sexual maturity (females), food intake, and growth were measured individually, and residual food intake and metabolic body weight were estimated using standard methods. A genome scan using 104 microsatellite markers was carried out to identify QTLs affecting behavioral traits. Phenotypic growth rates at different ages showed weak associations in both sexes. Sexual maturity and egg weight were not strongly correlated to growth, indicating that these traits are not genetically linked. Time spent in each arm and in the central part of the maze was analyzed using principal component analyses. Four principal components (PC) were extracted, each reflecting a pattern of behavior in the maze. Females with early onset of sexual maturity scored higher on the PC1 reflecting preference for free food without social stimuli, and females with higher egg production scored higher on the PC2 reflecting exploration. Males with an overall higher growth rate and higher residual food intake scored higher on the PC3, which possibly reflected fear of the test situation, and tended to score higher on the PC4 reflecting low contrafreeloading. Significant QTLs were found for PC1 and PC4 scores on chromosomes 27 and 7, respectively. The location of the QTLs coincided with known QTLs for growth rate and body weight. The results suggest a trade-off between energy-demanding behavior and high production and that some of this may be caused by genetic linkage or pleiotropic gene effects.

Animals↗
PubMed2006

The origin of European cattle: evidence from modern and ancient DNA.

Cattle domestication from wild aurochsen was among the most important innovations during the Neolithic agricultural revolution. The available genetic and archaeological evidence points to at least two major sites of domestication in India and in the Near East, where zebu and the taurine breeds would have emerged independently. Under this hypothesis, all present-day European breeds would be descended from cattle domesticated in the Near East and subsequently spread during the diffusion of herding and farming lifestyles. We present here previously undescribed genetic evidence in contrast with this view, based on mtDNA sequences from five Italian aurochsen dated between 7,000 and 17,000 years B.P. and >1,000 modern cattle from 51 breeds. Our data are compatible with local domestication events in Europe and support at least some levels of introgression from the aurochs in Italy. The distribution of genetic variation in modern cattle suggest also that different south European breeds were affected by introductions from northern Africa. If so, the European cattle may represent a more variable and valuable genetic resource than previously realized, and previous simple hypotheses regarding the domestication process and the diffusion of selected breeds should be revised.

Animals↗
PubMed2006

Overdominant quantitative trait loci for yield and fitness in tomato.

Heterosis, or hybrid vigor, is a major genetic force that contributes to world food production. The genetic basis of heterosis is not clear, and the importance of loci with overdominant (ODO) effects is debated. One problem has been the use of whole-genome segregating populations, where interactions often mask the effects of individual loci. To assess the contribution of ODO to heterosis in the absence of epistasis, we carried out quantitative genetic and phenotypic analyses on a population of tomato (Solanum lycopersicum) introgression lines (ILs), which carry single marker-defined chromosome segments from the distantly related wild species Solanum pennellii. The ILs revealed 841 quantitative trait loci (QTL) for 35 diverse traits measured in the field on homozygous and heterozygous plants. ILs showing greater reproductive fitness were characterized by the prevalence of ODO QTL, which were virtually absent for the nonreproductive traits. ODO can result from true ODO due to allelic interactions of a single gene or from pseudoODO that involves linked loci with dominant alleles in repulsion. The fact that we detected dominant and recessive QTL for all phenotypic categories but ODO only for the reproductive traits indicates that pseudoODO due to random linkage is unlikely to explain heterosis in the ILs. Thus, we favor the true ODO model involving a single functional Mendelian locus. We propose that the alliance of ODO QTL with higher reproductive fitness was selected for in evolution and was domesticated by man to improve yields of crop plants.

Chromosomes, Plant↗
PubMed2000

Expression pattern of Oct-4 in preimplantation embryos of different species.

POU transcription factors are involved in transcriptional regulation during early embryonic development and cell differentiation. Oct-4, a member of this family, has been shown to be under strict regulation during murine development. The expression of Oct-4 correlates with the undifferentiated cell phenotype of the mouse preimplantation embryo. In this study, expression of a gene construct consisting of selected parts of the region upstream from the murine Oct-4 gene as promoter/enhancer, enhanced green fluorescent protein (EGFP) as reporter and the five exons of the murine Oct-4 gene (GOF18-delta PE EGFP) was evaluated in murine, porcine, and bovine preimplantation embryos. For comparison, expression of the endogenous Oct-4 gene was also analyzed in all three species by immunocytochemistry. The transgene construct was microinjected into zygotes cultured in vitro to various developmental stages. The EGFP fluorescence was visualized in developing embryos by excitation with blue light at different days following microinjection and showed similar expression patterns in all three species. Most embryos displayed a mosaic pattern of transgene expression. The EGFP fluorescence was not restricted to the inner cell mass (ICM) but was also seen in trophoblastic cells. An affinity-purified polyclonal antibody specific to Oct-4 was used for immunocytochemical analysis of in vivo- and in vitro-derived bovine and porcine blastocysts and also of in vivo-derived murine blastocysts. In the in vivo-derived murine embryos, Oct-4 protein was detectable in the ICM but not the trophectoderm, whereas in porcine and bovine blastocysts, derived in vivo or in vitro, Oct-4 protein was detected in both the ICM and the trophectoderm. Thus, in the two large animal species, Oct-4 expression from the endogenous gene was clearly not restricted to the pluripotent cells of the early embryo. These results show that Oct-4 regulation differs between these species and that the presence of Oct-4 protein may not be sufficient for selection of undifferentiated cell lines in domestic animals.

Animals↗
PubMed2006

Does caloric restriction extend life in wild mice?

To investigate whether mice genetically unaltered by many generations of laboratory selection exhibit similar hormonal and demographic responses to caloric restriction (CR) as laboratory rodents, we performed CR on cohorts of genetically heterogeneous male mice which were grandoffspring of wild-caught ancestors. Although hormonal changes, specifically an increase in corticosterone and decrease in testosterone, mimicked those seen in laboratory-adapted rodents, we found no difference in mean longevity between ad libitum (AL) and CR dietary groups, although a maximum likelihood fitted Gompertz mortality model indicated a significantly shallower slope and higher intercept for the CR group. This result was due to higher mortality in CR animals early in life, but lower mortality late in life. A subset of animals may have exhibited the standard demographic response to CR in that the longest-lived 8.1% of our animals were all from the CR group. Despite the lack of a robust mean longevity difference between groups, we did note a strong anticancer effect of CR as seen in laboratory rodents. Three plausible interpretations of our results are the following: (1) animals not selected under laboratory conditions do not show the typical CR effect; (2) because wild-derived animals eat less when fed AL, our restriction regime was too severe to see the CR effect; or (3) there is genetic variation for the CR effect in wild populations; variants that respond to CR with extended life are inadvertently selected for under conditions of laboratory domestication.

Aging↗
PubMed2006

The effects of selective breeding against scrapie susceptibility on the genetic variability of the Latxa Black-Faced sheep breed.

Breeding sheep populations for scrapie resistance could result in a loss of genetic variability. In this study, the effect on genetic variability of selection for increasing the ARR allele frequency was estimated in the Latxa breed. Two sources of information were used, pedigree and genetic polymorphisms (fifteen microsatellites). The results based on the genealogical information were conditioned by a low pedigree completeness level that revealed the interest of also using the information provided by the molecular markers. The overall results suggest that no great negative effect on genetic variability can be expected in the short time in the population analysed by selection of only ARR/ARR males. The estimated average relationship of ARR/ARR males with reproductive females was similar to that of all available males whatever its genotype: 0.010 vs. 0.012 for a genealogical relationship and 0.257 vs. 0.296 for molecular coancestry, respectively. However, selection of only ARR/ARR males implied important losses in founder animals (87 percent) and low frequency alleles (30 percent) in the ram population. The evaluation of mild selection strategies against scrapie susceptibility based on the use of some ARR heterozygous males was difficult because the genetic relationships estimated among animals differed when pedigree or molecular information was used, and the use of more molecular markers should be evaluated.

Alleles↗
PubMed2005

thick tassel dwarf1 encodes a putative maize ortholog of the Arabidopsis CLAVATA1 leucine-rich repeat receptor-like kinase.

Development in higher plants depends on the activity of meristems, formative regions that continuously initiate new organs at their flanks. Meristems must maintain a balance between stem cell renewal and organ initiation. In fasciated mutants, organ initiation fails to keep pace with meristem proliferation. The thick tassel dwarf1 (td1) mutation of maize affects both male and female inflorescence development. The female inflorescence, which results in the ear, is fasciated, with extra rows of kernels. The male inflorescence, or tassel, shows an increase in spikelet density. Floral meristems are also affected in td1 mutants; for example, male florets have an increase in stamen number. These results suggest that td1 functions in the inflorescence to limit meristem size. In addition, td1 mutants are slightly shorter than normal siblings, indicating that td1 also plays a role in vegetative development. td1 encodes a leucine-rich repeat receptor-like kinase (LRR-RLK) that is a putative ortholog of the Arabidopsis CLAVATA1 protein. These results complement previous work showing that fasciated ear2 encodes a CLAVATA2-like protein, and suggest that the CLAVATA signaling pathway is conserved in monocots. td1 maps in the vicinity of quantitative trait loci that affect seed row number, spikelet density and plant height. We discuss the possible selection pressures on td1 during maize domestication.

Amino Acid Sequence↗
PubMed2002

Utilization of counseling and supportive services by female victims of domestic abuse.

Increasing attention to the high prevalence of domestic violence (DV) and its impact on women's physical and mental health has resulted in expanded services for abused women. Abused women appear to underutilize the formal counseling services available in many communities, however, and further research is needed to identify factors related to service utilization. In the present study, 1,746 women assaulted by a male intimate partner were identified from a larger pool of women interviewed by Pretrial Services following the arrest of their spouse/partner on domestic abuse charges. The women were selected for the current study if they reported prior physical assaults perpetrated by the same spouse/partner listed in the instant offense. In addition to describing previous physical assaults and psychological abuse by their current spouse/partner, women were also asked whether they had ever sought "formal counseling/supportive services" to address the abuse. Consistent with the prior literature, only a minority of the victims reported prior use of these services (14.9%). Additional analyses indicated that the likelihood of having accessed services varied as a function of victim demographic factors (race, relationship to the offender, income), characteristics of the prior DV (prior injury by partner, forced sexual activity, prior psychological abuse), and whether the victim's children witnessed the fighting. Limitations of the study and implications for service providers and the courts are discussed.

Adult↗