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  • Schlagwort: single nucleotide polymorphism x
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Low-density genotype panel for both parentage verification and discovery in a multi-breed sheep population

Abstract

The generally low usage of artificial insemination and single-sire mating in sheep, compounded by mob lambing (and lambing outdoors), implies that parentage assignment in sheep is challenging. The objective here was to develop a low-density panel of single nucleotide polymorphisms (SNPs) for accurate parentage verification and discovery in sheep. Of particular interest was where SNP selection was limited to only a subset of chromosomes, thereby eliminating the ability to accurately impute genome-wide denser marker panels. Data used consisted of 10,933 candidate SNPs on 9,390 purebred sheep. These data consisted of 1,876 validated genotyped sire–offspring pairs and 2,784 validated genotyped dam–offspring pairs. The SNP panels developed consisted of 87 SNPs to 500 SNPs. Parentage verification and discovery were undertaken using 1) exclusion, based on the sharing of at least one allele between candidate parent–offspring pairs, and 2) a likelihood-based approach. Based on exclusion, allowing for one discordant offspring–parent genotype, a minimum of 350 SNPs was required when the goal was to unambiguously identify the true sire or dam from all possible candidates. Results suggest that, if selecting SNPs across the entire genome, a minimum of 250 carefully selected SNPs are required to ensure that the most likely selected parent (based on the likelihood approach) was, in fact, the true parent. If restricting the SNPs to just a subset of chromosomes, the recommendation is to use at least a 300-SNP panel from at least six chromosomes, with approximately an equal number of SNPs per chromosome.

Open access
Leptin Promoter Region Genotype Frequencies and Its Variability in the Czech Fleckvieh Cattle

Abstract

To investigate the differences between the lineages of the Czech Fleckvieh cattle in Leptin promoter SNP C963T, 695 Czech Fleckvieh cows (650 from production herds and 45 from the Genetic Resources Program (GR)) were examined using PCR-RFLP. The C and T alleles of Leptin promoter were observed with a predominance of C allele in both groups. The most frequent genotypes were CC (63%) in production herds and CT (48%) in the GR population. The present study describes, for the first time, the genetic differences in production herds and GR population in Leptin promoter C963T SNP. Variation within the Czech Fleckvieh population was observed and resulted in an advantage to the GR population. Results presented herein emphasized the importance of the GR program as a reservoir of genetic diversity for indigenous breeds.

Open access
Single nucleotide polymorphisms in genes MACC1, RAD18, MMP7 and SDF-1a as prognostic factors in resectable colorectal cancer

Abstract

Background

Colorectal cancer (CRC) represents one of the most common malignancies worldwide. Research has indicated that functional gene changes such as single nucleotide polymorphism (SNP) influence carcinogenesis and metastasis and might have an influence on disease relapse. The aim of our study was to evaluate the role of SNPs in selected genes as prognostic markers in resectable CRC.

Patients and methods

In total, 163 consecutive patients treated surgically for CRC of stages I, II and III at the University Medical Centre in Maribor in 2007 and 2008 were investigated. DNA was isolated from formalin-fixed paraffin-embedded CRC tissue from the Department of Pathology and SNPs in genes SDF-1a, MMP7, RAD18 and MACC1 were genotyped using polymerase chain reaction followed by high resolution melting curve analysis or restriction fragment length polymorphism.

Results

We found worse disease-free survival (DFS) for patients with TT genotype of SNP rs1990172 in gene MACC1 (p = 0.029). Next, we found worse DFS for patients with GG genotype for SNP rs373572 in gene RAD18 (p = 0.020). Higher frequency of genotype GG of MMP7 SNP rs11568818 was found in patients with T3/T4 stage (p = 0.014), N1/N2 stage (p = 0.041) and with lymphovascular invasion (p = 0.018). For MACC1 rs1990172 SNP we found higher frequency of genotype TT in patients with T3/T4 staging (p = 0.024). Higher frequency of genotype GG of RAD18 rs373572 was also found in patients with T1/T2 stage with disease relapse (p = 0.041).

Conclusions

Our results indicate the role of SNPs as prognostic factors in resectable CRC.

Open access
Genomic descriptors of biodiversity – A review

Summary

The characterization of livestock genetic diversity has experienced extensive changes with the availability of dense nucleotide markers. Among the various forms of markers, the single nucleotide polymorphisms (SNP) have arguably the largest influence. A wide range of indicators for the assessment of genetic diversity was developed, or the existing methods were improved, enabling us to make informed decisions on the management of livestock populations. This review discusses the selected aspects of diversity assessment, with special attention to the SNP based methods.

One of the core concepts in genomics of diversity is the linkage disequilibrium (LD), as it was shaped by demographic events during the development of breeds and species. These events, either natural or artificial, left detectable signals within the livestock genomes. Further changes were induced by human activity when mating related animals, leading to fixing or improving the desired traits in the breed, but reducing their genetic variability. The assessment of relatedness is also pivotal to construct meaningful mating plans and to avoid the negative consequences of inbreeding depression that might be detrimental especially in small, endangered populations. Both LD and relatedness are of interest on their own, as well as in their follow-up applications deriving overall measures of effective population size.

Open access
Melatonin Receptor 1B Gene Polymorphisms, Haplotypes and Susceptibility to Schizophrenia

Abstract

Melatonin has an important role in the regulation of human sleep circadian rhythms. Sleep disturbances commonly exist in schizophrenia (SCZ) patients. To begin its performance, melatonin must interact to its receptor. In the present study, Single Nucleotide Polymorphisms (SNPs) of melatonin receptor gene 1 B (MTN1B) with SCZ development in Iranian population were investigated. The current case-control study was performed on 92 SCZ patients and 92 healthy control (HC) subjects. NESTED-PCR and ARMS-PCR modified methods (combination) and ARMSPCR method were used on the genotype. The impact of MTN1B rs3781637 (T/C) and rs10830963(C/G) polymorphism variants on the risk SCZ in the sample of Iranian population was investigated. The findings showed significant association between MTN1B rs10830963(C/G) variant and SCZ (OR=2.78, 95%CI=1.25-6.25, P=0.012, GG vs. CC, OR=1.66, 95%CI=1.09-2.51, P=0.021 G vs. C, OR=3.85 95%CI=.89-8.33, P<0.0001, GG vs. CC+CG). There was no association between MTN1B rs3781637 (T/C) and SCZ risk. In addition, haplotype analysis revealed that TG and CC haplotype of rs3781637 (T/C) and rs10830963 (C/G) polymorphisms were associated with SCZ risk (P=0.039) and protective (P<0.0001) effects, respectively. The findings revealed that MTN1B rs10830963 (C/G) polymorphism was associated with the risk of SCZ; while another SNP rs3781637 (T/C) MTN1B gene did not show any risk/protection association with SCZ. Further studies with larger sample sizes and different ethnicities are required to approve the results.

Open access
Insulin-like growth factor-I gene polymorphism and its association with growth and slaughter characteristics in broiler chickens

Insulin-like growth factor-I gene polymorphism and its association with growth and slaughter characteristics in broiler chickens

Chicken insulin-like factor 1 gene (IGF1) is a biological candidate gene for the investigation of growth, body composition, and metabolic and skeletal traits, and is also a positional candidate gene for growth and fat deposition in chickens. Two broiler populations Ross 308 and Cobb 500 were used to study the relationship between IGF1 gene polymorphism and phenotypic traits. A single nucleotide polymorphism (SNP) was identified in 132 individuals using the PCR-RFLP technique. Genotypical frequencies were, for genotype AA: 0.83-0.86, and for AC: 0.14-0.17. Associations between IGF1 promotor polymorphism and liver weight (P≤0.05) and liver weight as a percentage of the weight of the poultry carcass with the giblets (P≤0.05), were found in the AC genotype in a comparison of broiler homozygous chickens AA in the Cobb 500 line. In these broilers, the breast muscle and leg muscle weight in the AC genotype were higher, and abdominal fat weight lower compared with AA genotype chickens, but these differences were not significant.

Open access
Y Chromosome Single Nucleotide Polymorphisms Typing by SNaPshot MINISEQUENCING

Y Chromosome Single Nucleotide Polymorphisms Typing by SNaPshot MINISEQUENCING

Analysis of Y chromosome haplogroups, defined by single nucleotide polymorphisms (SNPs), is now a standard approach for study of the origin of human populations and measurement of the variability among them. It is also a new forensic tool, because it may allow determination of the origin of any male sample of interest. We have used a strategy for rapid, simple and inexpensive Y chromosome SNP typing of 343 male DNA samples, of which 211 were Macedonians, 111 Albanians and 21 Roma, Serbs or Turks. Using multiplex polymerase chain reaction (mPCR) and a SNaPshot multiplex kit for single nucleotide extension reaction, 28 markers were grouped into five multiplexes. Twenty different Y haplogroups were found in these samples. The most common Y haplogroups in Macedonians were I2a-P37b (27.5%), E1b1b1a-M78 (15.6%), R1a1-SRY1532 (14.2%) and R1b1-P25 (11.4%). In the Albanians E1b1b1a-M78 accounted for 28.8%, R1b1-P25 for 18.0%, J2b2-M241 for 13.5% and R1a1-SRY1532 for 12.6%. We conclude that five haplogroups (E1b1b1a-M78, I2a-P37b, J2b2-M241, R1a1-SRY1532 and R1b1-P25) comprised 72.6% of the Y chromosomes, this being characteristic of the typical European Y chromosome gene pool.

Open access
DICENTRIC CHROMOSOME 14;18 PLUS TWO ADDITIONAL CNVs IN A GIRL WITH MICROFORM HOLOPROSENCEPHALY AND TURNER STIGMATA

ABSTRACT

We report a 20-year-old female with features evocative of Turner syndrome (short stature, broad trunk, mild webbed neck), dysmorphic face, minor features of holo-prosencephaly (HPE), small hands and feet, excessive hair growth on anterior trunk and intellectual disability. Cytogenetic analysis identified a pseudodicentric 14;18 chromosome. Genome wide single nucleotide polymorphism (SNP) array showed a terminal deletion of approximately 10.24 Mb, from 18p11.32 to 18p11.22, flanked by a duplication of approximately 1.15 Mb, from 18p11.22 to 18p11.21. In addition, the SNP array revealed a duplication of 516 kb in 16p11.2. We correlated the patient’s clinical findings with the features mentioned in the literature for these copy number variations. This case study shows the importance of microarray analysis in the detection of cryptic chromosomal rearrangements in patients with intellectual disability and multiple congenital anomalies

Open access
Analysis in silico of the single nucleotide polymorphism G–152A in the promoter of the angiotensinogen gene of Indonesian patients with essential hypertension

Abstract

Background

Single nucleotide polymorphism (SNP) G–152A (rs11568020) in the promoter of the angiotensinogen gene (AGT) may modulate its transcription. Translation of mRNA to angiotensinogen induces hypertension during hypoxia. The G allele at position –152 is located within the hypoxia-response element (HRE) transcription factor-binding site for the hypoxia-inducible factor 1 (HIF-1) heterodimer. However, the function of the –152 site in HIF-1 binding is not fully elucidated.

Objectives

To determine the frequency of SNP G–152A in Indonesian patients with hypertension and the function of this SNP.

Methods

We determined the frequency of the SNP in 100 patients by direct sequencing, and the influence of SNP G–152A on predicted binding of HIF-1 to the HRE using a docking approach in silico.

Results

The AGT promoter in our patients had genetic variants –152G and –152A (19:1). Predicted binding indicated that HIF-1 directly contacts the major groove of the G allele, but not the A allele. Scoring according to weighted sum High Ambiguity Driven biomolecular DOCKing showed that the score for the A allele–HIF-1 complex (–47.1 ± 6.9 kcal/mol) was higher than that for the G allele–HIF-1 complex (–94.6 ± 14.1 kcal/mol), indicating more favorable binding of HIF-1 to the G allele.

Conclusions

SNP G–152A reduces the favorability of binding of HIF-1 to the HRE. The occurrence of this SNP in the AGT promoter of Indonesian patients with essential hypertension suggests that the G allele is a genetic susceptibility factor in hypertension regulated by HIF-1.

Open access
Polymorphism of the IL13 gene may be associated with Uterine leiomyomas in Slovenian women

Abstract

Uterine leiomyomas (ULM) are a common cause of solid pelvic tumors in women. Their etiopathogenesis remains unclear. Interleukins (ILs) and their receptors can influence tumor biology of ULM. The aim of this study was to evaluate single nucleotide polymorphisms (SNPs) exhibited in the genes IL4 (rs2070874), IL4R (rs1801275), IL12RB1 (rs11575934), IL12B (rs6887695), IL13 (rs20541) and IL23R (rs7517847) as risk factors for ULM in Slovenian women and to identify associations between corresponding clinical parameters and the analyzed SNPs. In addition, solitary and multiple ULM were compared to identify clinical and/or genetic parameters influencing their occurrence. We conducted a case-control study that included 181 women with leiomyomas and 133 control subjects. Genotyping of selected SNPs was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and high resolution melting (HRM) techniques. The TT genotype of rs20541 (IL13) was significantly associated with decreased risk of ULM compared to both the CC and CT genotypes [p = 0.018; odds ratio (OR) = 0.184; 95% confidence interval (95% CI) = 0.048-0.7121. Using genetic and clinical data to develop a predictive model with logistic regression, we found that adenomyosis, higher age at diagnosis, family history of ULM occurrence, earlier menarche, lower number of pregnancies and lower age at first sexual intercourse, the G allele and genotypes AG and GG of rs1801275 (IL4R) were associated with an increased risk of multiple ULM occurrence. We also found an association between rs20541 (IL13) and 17ß-estradiol serum levels in patients with multiple ULM (p 0.003). Our study showed, for the first time, that rs20541 (IL13) may contribute to susceptibility of ULM development and that rs1801275 (IL4R) can predispose patients to develop multiple ULM.

Open access