Kazimierz Jaszczak

Canine Olfactory Receptor Gene Polymorphism and Its Relation to Odor Detection Performance by Sniffer Dogs

The outstanding sensitivity of the canine olfactory system has been acknowledged by using sniffer dogs in military and civilian service for detection of a variety of odors. It is hypothesized that the canine olfactory ability is determined by polymorphisms in olfactory receptor (OR) genes. We investigated 5 OR genes for polymorphic sites which might affect the olfactory ability of service dogs in different fields of specific substance detection. All investigated OR DNA sequences proved to have allelic variants, the majority of which lead to protein sequence alteration. Homozygous individuals at 2 gene loci significantly differed in their detection skills from other genotypes. This suggests a role of specific alleles in odor detection and a linkage between single-nucleotide polymorphism and odor recognition efficiency.

Differences in ethanol drinking between mice selected for high and low swim stress-induced analgesia

Alcoholism is a complex disorder, still not fully understood, in which environmental and inherited risk factors play essential roles. Of particular importance may be chronic exposure to stress thought to increase preference for ethanol in genetically susceptible individuals. Animal and human data suggest that the opioid system may be involved in the development of alcohol dependence. We studied the effects of chronic mild stress (CMS) on the voluntary intake of 8% ethanol in the mouse lines displaying high (HA) or low (LA) swim stress-induced analgesia. These lines differ in the activity of the endogenous opioid system. Normally, 8% ethanol is aversive to rodents. We found that LA mice with the low opioid system activity exposed to CMS manifested greater ethanol intake than under no stress conditions. No such effect of CMS on ethanol consumption was observed in HA mice that display the enhanced opioid system activity. We conclude that CMS imposed on individuals with a genetically determined low opioid activity may favor the development of ethanol abuse.

A polymorphism in exon 2 of the δ-opioid receptor affects nociception in response to specific agonists and antagonists in mice selectively bred for high and low analgesia

&NA; This study searched for polymorphic sites in the murine &mgr;‐, &dgr;‐ and &kgr;‐opioid receptors that presumably influence pain perception. We employed two mouse lines divergently bred for high (HA, high analgesia line) and low (LA, low analgesia line) swim stress‐induced analgesia (SSIA). These mouse lines differ substantially in pain sensitivity, measured as hind paw withdrawal latency in the hot‐plate test. We found a novel C320T transition in exon 2 of the &dgr;‐opioid receptor gene, resulting in an A107V substitution in the first extracellular loop (EL1) of the peptide chain. Using hot‐plate and tail‐flick tests, we found a significant association between the genotype of this locus and basal nociception and SSIA magnitude. Moreover, this transition affects the pharmacological effects of two specific &dgr;‐opioid receptor ligands, the agonist SNC80 and the antagonist naltrindole. The impact of the C320T polymorphism on the magnitude of SSIA was partially mediated by endogenous opioids. The effectiveness of exogenous &dgr;‐opioid receptor ligands was greater in the HA than in the LA line, and was greater in C320C homozygotes than in C320T heterozygotes within each line. Our results indicate that the C320T polymorphism in the &dgr;‐opioid receptor gene is at least partly responsible for the divergent nociceptive thresholds in HA and LA mice under both basal and post‐stress conditions.

The use of microsatellite polymorphism in genetic mapping of the ostrich (Struthio camelus)

The aim of this study was to determine microsatellite polymorphism in ostriches and using it in creation the genetic map of the ostrich. The polymorphism analysis covered 30 microsatellite markers characteristic of ostrich, for the CAU (China Agricultural University) group. The material consisted of 150 ostriches (Struthio camelus). The 30 microsatellite loci was examined and a total of 343 alleles was identified. The number of alleles at a single locus ranged from 5 at locus CAU78 to 34 at locus CAU85. The values for the observed heterozygosity Ho ranged from 0.467 (locus CAU78) to 0.993 (locus CAU16), whereas for the expected heterozygosity He - from 0.510 (locus CAU78) to 0.953 (locus CAU85). Analyzing the individual loci, the highest PIC value, more than 0.7 was observed for: loci CAU85 (0.932), CAU64 (0.861) and CAU32, 75 (0.852), respectively. It should be noted, that the microsatellite markers used in our study were very polymorphic as evidenced by the large number of detected alleles and high rates of heterozygosity, PIC and PE as well. The analysed microsatellite markers may be used in genetic linkage mapping of ostrich, the construction of a comparative genetic map with other ratites, such as emu and rhea, and population genetics studies or phylogenetic studies of these birds.

The comparative analysis of NOR polymorphism detected by FISH and Ag-staining on horse chromosomes

Summary The nucleolus organizer regions were investigated by FISH with biotinylated rDNA probe and silver staining on chromosomes of the domestic horse (Equus caballus}. Ribosomal RNA loci were mapped at the secondary constrictions of the short arm of chromosome 1 and at the pericentromeric regions of chromosomes 27, 28 and 31. A new nucleolus-organizing chromosome 27 was identified. The interindividual, and interchromosomal polymorphism of NORs was described in 26 horses from 5 breeds. The relative rRNA gene activity was evaluated by the number of silver-stained chromosomes, and the size of silver deposits. The relative amount of rDNA in NORs was estimated by intensity of fluorescent hybridization signals. The size of silver deposits and intensity of fluorescence after FISH were determined for each NOR using arbitrary scales of 0–3 and 0–5, respectively. The statistical analysis of these data revealed a tendency for differentiation of NOR-bearing chromosome pairs by the rRNA gene number of copies, and th...

Chromosomal NOR Activity in Mice Selected for High and Low Swim Stress-Induced Analgesia

Metaphase nucleolar organizer region (NOR) activity was studied in mouse lines selectively bred for high analgesia (HA) and for low analgesia (LA) induced by 3-min swimming in 20°C water. Apart from pain-related traits, HA mice also manifest, as compared to the LA line, higher emotionality in certain behavioral tests and are less capable of coping with the hypothermic challenge of swimming in cold water, in addition to being more susceptible to the mutagenic effect of whole-body γ-radiation and mitomycin C injection. We here compared NOR activity in HA and LA mice. A statistically significant difference (p ≤ .01) was detected in mean silver-stained nucleolar number/cell between the HA and LA lines, being lower for HA mice. We propose that the breeding strategy, along with the differentiation of stress-related phenomena, has altered the activity of genes coding rRNA and that this activity is important in controlling DNA repair in each line. It is concluded that quantitative studies of nucleolar changes may be useful in evaluating the biological reactivity to stress stimuli.

Opposite effects of alcohol in regulating stress-induced changes in body weight between the two mouse lines with enhanced or low opioid system activity.

Considering the involvement of the opioid system in alcoholism, depression and metabolism - known risk factors in human obesity, we studied the effects of chronic mild stress (CMS) and alcohol intake on body weight in two mouse lines selected for high (HA-high analgesia) or low (LA-low analgesia) swim stress-induced analgesia. In comparison to LA mice, HA mice exhibit an upregulation of opioid receptor system function, different depression-like behavior and reduced energy expenditure in stress. LA animals showed enhanced basal and CMS-induced alcohol drinking versus HA. Now we report different effects of alcohol under no stress (control) and CMS conditions on food intake and body weight between the lines. CMS in animals with no access to alcohol increased body weight in both HA and LA mice, with no effect of CMS on food intake in either line and without differences between the lines. In LA mice alcohol reduced body weight under both conditions although significantly more under the control than CMS conditions. In contrast, in HA mice alcohol increased body weight more under the CMS than under control conditions. The results suggest that opioid system may modulate effects of alcohol on stress -induced changes in body weight.

Microsatellite markers may be ineffective in selection of laying hens for polygenic production traits

Previous research on mapping QTL in a reference family of laying hens indicated that 5 microsatellite loci (MCW0133, MCW0170, MCW0114, MCW0139, and LEI0074) were significantly associated with genome regions affecting shell strength as well as egg and yolk weights. The aim of our investigation was to verify if those markers could be useful in selection of laying hens. The study involved 2 breeds of randomly segregating populations: Rhode Island Reds selected divergently and Green-legged Partridgenous chickens selected upwardly, over 4 generations, for the mentioned egg quality traits. The influence of marker genotype on bird performance was assessed through the prediction of breeding values using a model that distinguished the marker effect from that of the polygenic effect and by comparing breeding values between different genotypes at given marker loci. The effects of the linked QTL regions appeared too small to significantly differentiate the outcomes of classifications fitting or not fitting the marker genotype. Comparison of breeding values between microsatellite genotypes for laying and egg traits revealed that antagonistic pleiotropic effects exist between these 2 groups of traits, adding to the difficulty of accounting for marker genotypes in the selection of laying hens.

Studies on resources of genetic diversity in conservative flocks of geese using microsatellite DNA polymorphic markers

The studies conducted aimed at evaluating the genetic diversity within and between varieties of conservative flocks of geese, using the polymorphism of 14 microsatellite sequences. The experimental material included conservative flocks of geese the following indigenous breeds and varieties kept in Poland: Kielecka (Ki), Kartuska (Ka), Lubelska (Lu), Suvalska (Su), Rypinska (Ry), Sub-Carpathian (SC), Hunched Beak (HB) and Pomeranian (Po). Among the 14 microsatellite sequences a total of 97 microsatellite alleles were identified. The number of alleles at one locus ranged from 3 to 19. In the overall pool of 97 alleles, 26 (26.8%) were specific for individual breeds and varieties of geese. The values of the expected heterozygosity (He) for individual geese ranged from 0.38 (Sub-Carpathian) to 0.51 (HB). Similarly, the mean values for the observed heterozygosity (Ho) ranged from 0.45 (Po) to 0.55 (Ki and Su). The polymorphic information content reached the highest value of 0.80 at loci CKW21 (Ki) and TTUCG5 (Po and Su). The greatest genetic distance was observed between the HB and Ry (0.44) and between the HB and Po (0.39) varieties, while the smallest–between the Lu and Po as well as Lu and Ki (0.028) varieties. The phylogenetic tree, elaborated on the basis of the genetic distances, clearly confirms the specificity of the HB goose as compared to the remaining breeds and varieties.

Alternative Transcription of Peroxisome Proliferator-Activated Receptor Gamma in the Liver Is Associated with Fatness of Chickens

The expression of four transcription variant of peroxisome proliferatoractivated receptor gamma gene (PPARG) (XM_015292931.1; XM_015292932.1; XM_015292933.1 and NM_001001460.1) in the liver of broilers was measured and its correlation with abdominal fat weight and relative abdominal fat content was investigated. The study was conducted with 92 slow-growing crossbred chickens (Cobb males x indigenous Green-legged Partridge female chickens) divided into “fat” and “lean” groups, according to their abdominal fat yield. The NM_001001460.1 transcriptwas upregulated with ratio of means 4.26 (p≤0.01) in the “fat” group in relation to the “lean” group. Expression of this transcript was highly correlated with relative abdominal fat content (0.71, p≤0.01) and abdominal fat weight (0.59, p≤0.01). Two SNPs are located in putative transcription factor binding sites. Mutation -991C>A disrupts PPAR while mutation -884C>T disrupts C/EBP putative binding site. The gene expression analysis of PPARg showed that the expression of the transcripts (NM_001001460.1) was more than four times higher in fat than in lean chickens. These results point out that the peroxisome proliferator-activated receptor gamma NM_001001460.1 transcript could be candidate gene for determination of abdominal fat deposition in the chickens.