Homozygous NN Research Articles

The effect of the ryanodine receptor gene on the reproductive traits of Welsh sows

The reproductive performance of sows largely determines the efficiency of the entire pig farming industry. The purpose of our work is the evaluation of polymorphism of the ryanodine receptor gene and its impact on the reproductive traits of sows of the Welsh breed of pigs. For this study, 148 pigs of the Welsh breed were used. The reproductive traits of sows were evaluated in two adjacent generations. We conducted a comprehensive assessment of the reproductive ability of sows using the SIRQS (selection index of reproductive qualities of sows), determined phenotypic consolidation coefficients and assessed the genetic potential of the animals’ productivity. The polymorphism of the RYR1 gene was determined using polymerase chain reaction-restriction fragment length polymorphism analysis (PCR-RFLP). Data processing was performed using single-factor analysis of variance (ANOVA). Polymorphism of the ryanodine receptor gene in sows of the Welsh pig breed was evaluated. 8.0% of the animals were identified as carriers of the mutant allele of the RYR1 gene. However, no homozygous RYR1-nn animals were found. Pigs of the maternal generation carrying the homozygous NN genotype had better reproductive performance in all indicators. Sows that were carriers of the mutant allele were characterized by lower values of the genetic productivity potential compared with the entire estimated population for all productive traits. Sows which were free of the mutant allele of the RYR1 gene were characterized by large values of the SIRQS index. The values of the coefficients of phenotypic consolidation of the number of live born piglets in sows without the mutant allele were lower than in sows with the mutant allele n. Better performance of sows free of the mutant allele of the RYR1 gene was established over sows carrying it in all evaluated traits of reproductive capacity (for different traits P ranged from 0.021 to 1.0*10–4), except for number of piglets born alive per sow in the daughter generation. Sows with the NN genotype had better selection index values by 15.7% in the maternal generation and by 10.2% in the daughter generation. In order to increase the reproductive ability of sows in the studied population of Welsh pigs and achieve similar results in other herds of this breed, animals free from the mutant allele of the RYR1 gene should be selected for further reproduction in the process of breeding, while on the contrary, carriers of this gene should be gradually eliminated from the herd. To carry out breeding work, further research is needed on the entire population of Welsh pigs for the RYR1 gene.

CAST/MspI gene polymorphism and its impact on growth traits of Soviet Merinoand Salsk sheep breeds in the South European part of Russia

The purpose of this work was to study MspI polymorphism in the CAST gene in Soviet Merino and Salsk sheep breeds in the South European part of Russia and to find its relation with growth traits. Soviet Merino sheep have been found to have the M and N alleles with a frequency of 0.88 and 0.12 and the MM, MN, and NN genotypes with a frequency of 0.82, 0.12, and 0.06, respectively. Salsk sheep have been established to have the M and N alleles with a frequency of 0.89 and 0.11 and two genotypes, MM and MN, with a frequency of 0.78 and 0.22, respectively. A significant relationship between the CAST genotypes and the growth traits of Salsk sheep has been revealed. The absence of the homozygous NN genotype in Soviet Merino sheep did not allow us to determine what exactly causes the effect of increasing the average daily gain of sheep - the presence of the N allelic variant or the combination of the heterozygous M and N alleles. The results obtained show the CAST/MspI gene to be promising as a marker of sheep production in developing sheep breeding programs to improve fattening and meat qualities.

The Ser680Asn polymorphism in the follicle-stimulating hormone receptor gene is associated with the ovarian response in controlled ovarian hyperstimulation.

Polymorphisms in the follicle-stimulating hormone receptor (FSHR) gene are reported to be associated with the ovarian response in controlled ovarian hyperstimulation (COH), although there remains some discordance between studies. Here, using the largest patient sample to date, we evaluated the association of the p.Ser680Asn (S(680)N) polymorphism in the FSHR gene with the outcome of COH. Cohort study. Medical academy and hospital. A total of 1250 infertile Chinese women undergoing IVF/ICIS-ET treatment were included. The association between an FSHR polymorphism (S(680)N) and the ovarian response was analysed. Genotyping was performed by utilizing direct sequencing and the Sequenom MassARRAY iPLEX platform. Follicular fluid oestradiol (E₂) and follicle-stimulating hormone (FSH) concentrations were determined using electrochemiluminesence immunoassays. The ovarian response parameters were analysed based on the FSHR genotypes. The odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated for the risk genotypes and alleles. There were linear correlations between the basal FSH level, exogenous gonadotropin consumption, and oocytes retrieved and the Ser680 alleles. Patients in the homozygous SS group demonstrated higher basal FSH levels, required more dosage of exogenous gonadotropin for ovarian stimulation, and had fewer numbers of oocytes retrieved compared with patients in the homozygous NN and heterozygous groups. Logistic regression analysis revealed that the OR of a poor ovarian response for the NS genotype was 1·79 (95% CI 1·28-2·61; P < 0·001), whereas that for the SS genotype was 2·25 (95% CI 1·40-3·58; P < 0·001) after adjusting for age, BMI and basal FSH level. The concentration of E2 in the follicular fluid was significantly higher in subjects with the NN genotype than the SS genotype (772 ± 545 ng/ml vs. 1299 ± 504 ng/ml). Follicle-stimulating hormone receptor gene polymorphism at position 680 is associated with different ovarian responses to controlled ovarian hyperstimulation.

The Role of Endothelial PECAM-1 Polymorphism (S536N) as Heterophilic Counter Receptor for Neutrophil Specific CD177 in Transendothelial Cell Migration.

The human neutrophil-specific adhesion antigen CD177 (NB1, HNA-2a or PRV-1) becomes upregulated on the cell surface in a number of inflammatory settings, and human alloantibodies specific for CD177 have been implicated in the development of transfusion related acute lung injury (TRALI). Recent studies have shown that CD177 functions as an important counter-receptor for the endothelial cell-cell junctional protein PECAM-1 (CD31) – a heterophilic adhesive interaction that appears to be mediated by Ig domain 6 of PECAM-1 and a still-to-be-identified site on CD177. Interestingly, a common single nucleotide polymorphism (SNP) exists within the PECAM-1 gene that produces an S536N amino acid substitution within Ig domain 6 that is proximal to the CD177 binding site. Whether this polymorphism influences PECAM-1/CD177 interactions and subsequent neutrophil transendothelial cell migration, however, is not known. To investigate the potential for the S536N PECAM-1 SNP to affect functionally important interactions between PECAM-1 and CD177, recombinant CD177 and PECAM-1 S536 or N536 allelic isoforms were produced in CHO mammalian cells, purified by affinity chromatography, and subjected to surface plasmon resonance analysis. We found that the S536 isoform of PECAM-1 bound with much higher affinity to CD177 than did its N536 counterpart (Ka for PECAM-1S536/CD177 = 5×10−7 versus a Ka for PECAM-1N536/CD177=1×10−7). To analyze the possible functional impact of the S536N polymorphism on neutrophil transendothelial migration, fMLP-stimulated neutrophils were allowed to transmigrate across human umbilical vein endothelial cell (HUVEC) monolayers that had been genotyped to be either PECAM-1 homozygous SS, heterozygous NS, or homozygous NN. We found that neutrophils migrated significantly faster across HUVECs expressing the PECAM-1S536, rather than the PECAM-1N536, allelic isoform. In addition, western blot analysis using a phospho-specific antibody revealed that cytoplasmic PECAM-1 ITIM tyrosines became phosphorylated to a greater extent in PECAM-1S536- versus PECAM-1N536-expressing HUVECs that had been incubated with either soluble recombinant CD177 or an anti-PECAM-1 mAb specific for Ig domain 6. Taken together, these data demonstrate thatheterophilic interactions between neutrophil CD177 and endothelial cell PECAM-1 play an important role in neutrophil transendothelial migration, andthe naturally-occurring S536N polymorphism within Ig domain 6 likely affects ligand binding-induced downstream PECAM-1 signaling.Allele-specific, PECAM-1-mediated effects on neutrophil transendothelial migration and inflammatory events such as TRALI may represent an important area for future investigation.

&amp;lt;sup&amp;gt;13&amp;lt;/sup&amp;gt;C nuclear magnetic resonance spectroscopy – a non-invasive &amp;lt;i&amp;gt;in vivo&amp;lt;/i&amp;gt; method to measure muscle glycogen metabolism in pigs of different genotypes

Abstract. The three ryanodine receptor 1 gene variants (NN: homozygous normal, Nn: heterozygous, nn: homozygous defective) and the degree of Hampshire origin (0 %, 25 %, 50 %) serve as model for the investigation of the in vivo glycogen muscle metabolism in 27 pigs. The pigs originate from 4 different cross-breeding lines with an age varying between 41 and 58 days and a body weight between 7.3 and 19 kg. 13C nuclear magnetic resonance spectroscopy was applied non-invasively in vivo and in a few pigs also post mortem to study the metabolic processes in the biceps femoris muscle after halothane exposure. In contrast to no visible effects of the halothane challenge test, the heterozygous defective allele carriers showed a drastic reduction in the level of glycogen (57 %) coupled with an increase in body temperature (1.36 °C). Overall, these changes were intermediate compared to the dramatic response in the homozygous nn genotype and to the very slow processes in NN, considering that the drastic glycogen depletion in the heterozygous genotype occurred after a rather long time of halothane exposure ( &gt;20 min). In addition, pigs with the highest degree of Hampshire origin (50% → RN– allele frequency: ~31.5 %) showed the slowest glycogen depletion compared to pigs with a lower degree of Hampshire origin (0 or 25 %).

Influence of halothane genotype and body-weight on myosin heavy chain composition in pig muscle as related to meat quality

In an effort to understand the relationship between muscle fiber type, live weight, genotype, and PSE development, enzyme-linked immunosorbent analyses were used to evaluate myosin heavy chain (MyHC) isoform content in the longissimus muscle of pigs differing in halothane gene status (nn, homozygous mutant; Nn, heterozygous; NN, homozygous normal) that were slaughtered at three different weights (100, 120 and 140 kg). Pigs carrying the n gene (Nn and nn) exhibited more IIB MyHC and less slow type I MyHC than those pigs free of the n gene, while NN pigs had greater amounts of IIAX MyHC. The relative abundance of IIB and IIAX MyHC in muscle of all pigs studied was strongly negatively correlated ( r=−0.834). Heavier pigs (140 kg) had the greatest amounts of slow and IIA MyHC. Across all genotypes, the relative abundance of IIB MyHC and muscle pH at 45 min postexsanguination (pH45) was negatively correlated ( r=−0.418). In addition, the relative amount of slow was positively correlated with pH45 ( r=0.386). Because muscle of homozygous nn positive pigs exhibited similar IIB/slow MyHC ratios to that of heterozygous Nn pigs, yet less desirable pH45 values and ultimate meat quality scores argues against a role of MyHC content per se in contributing to PSE development. However, these data do not preclude that those pigs with greater amounts of IIB MyHC are more ‘susceptible’ to adverse pork quality development than those pigs with less IIB MyHC.

Effects of the MHS locus on growth, carcass and meat quality traits in F&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; crosses between Mangalitza and Piétrain breeds

Abstract. A total of 345 F2 animals from a crossbred design Mangalitza (homozygous NN) x Piétrain (homozygous nn) were fed ad libitum at the institute's Thalhausen Research Station and slaughtered at a live weight of approximately 100 kg. MHS genotypes (67 nn, 192 Nn and 86 NN) were determined directly in a DNA test targeting the ryanodine reeeptor locus. Models for analysis of variance included sire, dam, pen, slaughter group, sex and MHS effects. Growth Performance was generally lower and carcass composition minor compared to other breeds and crosses. No significant differences were found between MHS genotypes for growth traits but NN animals tended to be less eflicient with respect to food conversion. However, nearly all measurements of the carcass showed significant differences between nn and NN which were especially pronounced for sidefat thickness (−7 1mm) fat over the musculus longissimus dorsi (−8.8 mm) and loin eye area (+8.7 cm2) as well as fat area (−5.1 cm2) We found Nn animals performing similar to NN animals due to incomplete dominance of the N allele. As expected nn had a substantial negative influence on meat quality compared to NN and Nn (e.g. −0.61 and −0.15 for pH 45 min, respectively). Intramuscular fat content was at a high level and nn had significantly lower values with differences of −0.40% and −0.25% relative to NN and Nn, respectively. A whole genome scan is currently underway with emphasis on fat measurements which showed promising Variation in this study.

Pork quality and the expression of stress protein Hsp 70 in swine

The expression of heat shock protein with a molecular weight of 70 kDa (Hsp 70) in porcine tissue and its potential relationship to stress susceptibility was studied. Twelve pigs, four of each genotype (NN, Nn, and nn) for halothane sensitivity were slaughtered. At 45 min postmortem, several tissues (liver, kidney, spleen, skeletal and cardiac muscle, and adrenal gland) were sampled for Hsp 70 analysis. At 24 h postmortem, longissimus and semimembranosus muscle were sampled for assessment of meat quality. Water-holding and water-binding capacity, color, and protein denaturation of samples from halothane-positive animals indicated that these animals had been stressed. Homozygous nn pigs demonstrated a lower pH45 and higher L-value at 48 h than their NN and Nn counterparts (P < .05). The longissimus, but not semimembranosus, muscle of nn pigs demonstrated lower water-holding capacity and greater protein denaturation than that of NN or Nn pigs (P < .05). The water-binding capacity of both longissimus and semimembranosus was less in nn than in Nn or NN pork (P < .05). Using one-dimensional PAGE and Western blotting, Hsp 70 was shown to be present in all tissues examined. With two-dimensional PAGE followed by blotting, the presence of the cognate and inducible form of Hsp 70 was investigated. There did not seem to be a relationship between stress (based on meat quality) and expression of either form of Hsp 70.

Frequencies of HPRT − lymphocytes and glycophorin A variants erythrocytes in Fanconi anemia patients, their parents and control donors

The mutant frequency of 6-thioguanine resistance ( HPRT locus) in circulating T lymphocytes from 23 Fanconi anemia (FA) patients has been determined. The glycophorin A (GAP) in vivo cell mutants assay, which detects allele lost variant phenotypes arising from mutationss in erythroid progenitor cells of GPA heterozygous MN individuals, has been applied in parallel to FA patients. No significant difference in frequency of HPRT − mutants was observed in FA compared to age matched healthy donors. In contrast, the mean frequency of GPA variants cells was elevated 31-fold for hemizygous NO variants and 8-fold for homozygous NN variants in FA patients over normal controls. In heterozygous FA parents, HPRT − mutant frequencies and GPA variant frequencies were within the normal change. Molecular analysis of HPRT − mutants has previously shown that FA cells have a high tendency to form deletions. Knowing that the cellular events allowing the detection of mutations at the HPRT and the GPA locus differ, our results emphasize the possible correlation between events of spontaneous loss of heterozygosity and genetic predisposition to cancer as observed in FA.

Application of the scale cover gene (N) to identification of type of gynogenesis and determination of ploidy in common carp

Eggs from nude common carp females heterozygous for the scale cover gene N (ssNn) were used for induction of mitotic gynogenesis and triploidy by heat shock. The type of scale cover for reared fingerling progeny was identified. Among gynogenetic progeny, 99.8% of fish were scattered (ssnn) and 0.02% were nude (ssNn). As the N gene has a very high frequency of recombination relative to the centromere, the occurrence of homozygous nn scattered fishes (NN homozygotes are inviable) proved the mitotic character of induced gynogenesis. In the triploidy experiment, eggs from nude females were inseminated with sperm collected from scattered males. In progeny produced with heat shock, the ratio of nude and scattered fishes was 13:1 instead of 1:1 usually observed at crossing between nude and scattered carp. Such a shift in the ratio in experimental progeny was explained as being due to the high recombination frequency for gene N artificially suppressing the second meiotic division, resulting in triploids with genotype Nnn. All scattered fingerlings karyologically investigated were diploids. It was found that nude triploid Nnn and nude diploid Nn fish differed in the rate of reduction of scale cover and soft rays in the anal fin. This provides an opportunity to identify triploids simply by means of external examination.