Two co-inherited SNPs of the telomerase reverse transcriptase (TERT) gene are associated with Iraqi patients with lung cancer.

Background: The telomerase reverse transcriptase (TERT) gene is essential polymorphic loci linked to most malignant tumors. This study assessed the association between the TERT gene and non-small cell lung carcinoma (NSCLC) in Iraq. Methods: Genomic DNA samples were extracted from a total of 200 samples of blood. Four specific PCR fragments were designed to amplify four high-frequency rs2735940, rs2736098, rs2736100, and rs10069690 SNPs within the TERT gene. Single-strand conformation polymorphism (SSCP) followed by sequencing reactions were used for genotyping and validating the amplified fragments.

The relationship between OXT gene polymorphisms and reproductive hormones in pregnant and lactating Awassi Ewes.

BACKGROUND: Numerous genetic loci interact intricately to control reproduction in mammals. The oxytocin gene (OXT) is a promising candidate for reproductive traits in mammals. Previously, sheep and goats have been studied for the presence of the OXT polymorphism. As of yet, no polymorphisms have been identified in the OXT gene of Awassi sheep. Thus, this study was conducted to determine the effects of OXT polymorphism and litter size on reproductive hormones in pregnant and lactating Awassi ewes. METHODS AND RESULTS: This study evaluated 232 ewes aged 3 and 4 years (123 single-progeny ewes and 109 twin-producing ewes). Serum was collected to measure reproductive hormones using ELISA kits manufactured by ELK Biotechnology. DNA was extracted from sheep blood for genotyping and sequencing to identify variations in OXT gene (exon 2, 266 bp). Genotyping analysis revealed three genotypes within 266 bp: CC, CA, and AA. Sequence analysis revealed a novel mutation in exon 2: 188 C > A. Statistical analysis showed significant associations between the 188 C > A SNP and phenotypic traits. Twin-pregnant ewes carrying CC genotypes had higher estrogen, progesterone, and follicle-stimulating hormone/luteinizing hormone levels (65.86 ± 3.87) (pg/mL), (6.51 ± 0.39) (ng/mL), and (20.22 ± 1.27) (ng/mL)/( 23.37 ± 2.14) (ng/mL) respectively, compared to CA and AA genotypes in the fourth month of twin-pregnant ewes compared to single-pregnant ewes. CONCLUSIONS: This study found that the 188 C > A SNP negatively affected reproductive hormone levels in Awassi sheep. These findings provide breeders with a new insight into the sheep OXT gene, useful for future breeding.

Association of Novel C319T Variant of PITX2 Gene 3'UTR Region With Reproductive Performance in Awassi Sheep.

Several genes influence sheep's reproductive performance, among them the paired-like homeodomain transcription factor 2 (PITX2) gene. Thus, this study aimed to examine whether the variability within the PITX2 gene is associated with the reproductive performance of Awassi ewes. A total of 123 single-progeny ewes and 109 twin ewes were used to extract genomic DNA. An amplicon of 4 sequence fragments from exons 2, 4, 5 (upstream portion), and 5 (downstream portion) of the PITX2 gene was generated by polymerase chain reaction (PCR), 228, 304, 381, and 382 bp, respectively. Three genotypes of 382 bp amplicons were identified: CC, CT, and TT. Sequence analysis revealed a novel mutation in the CT genotype 319C > T. Statistical analysis revealed that single-nucleotide polymorphism (SNP) 319C > T was associated with reproductive performance. Single-nucleotide polymorphism 319C > T-carrying ewes had significantly (P ⩽ .01) lower litter sizes, twinning rates, lambing rates, and more days to lambing than those carrying CT and CC genotypes. Based on a logistic regression analysis, it was confirmed that the 319C > T SNP decreased litter size. Ewes with TT genotype produced fewer lambs than ewes with CT and CC genotypes. According to these results, the variant 319C> T SNP negatively affects the reproductive performance of Awassi sheep. Ewes carrying the 319C > T SNP have a lower litter size and are less prolific than those without the SNP.

A Novel c.100C > G Mutation in the FST Gene and Its Relation With the Reproductive Traits of Awassi Ewes.

Reproductive traits are affected by many factors, including ovarian function, hormones, and genetics. Genetic polymorphisms of candidate genes are associated with reproductive traits. Several candidate genes are associated with economic traits, including the follistatin (FST) gene. Thus, this study aimed to evaluate whether the genetic variations in the FST gene are associated with the reproductive traits in Awassi ewes. The genomic DNA was extracted from 109 twin ewes and 123 single-progeny ewes. Therefore, 4 sequence fragments from the FST gene were amplified using polymerase chain reaction (PCR) (exon 2/240, exon 3/268, exon 4/254, and exon 5/266 bp, respectively). For a 254 bp amplicon, 3 genotypes were identified: CC, CG, and GG. Sequencing revealed a novel mutation in CG genotypes c.100C > G. The statistical analysis of c.100C > G showed an association with reproductive characteristics. Ewes carrying the c.100C > G had significantly (P ⩽ .01) lower litter sizes, twinning rates, lambing rates, and more days to lambing compared with CG and CC genotypes. Logistic regression analysis confirmed that the c.100C > G single-nucleotide polymorphism (SNP) is responsible for decreasing litter size. According to these results, the variant c.100C > G negatively affects the traits of interest and is associated with lower reproductive traits in Awassi sheep. As a result of this study, ewes carrying the c.100C > G SNP have lower litter size and are less prolific.

A Missense p.Q>R234 Mutation in the Osteopontin Gene Is Associated With the Prolificacy of Iraqi Awassi Ewes.

One of the most valuable traits in production and breeding is a sheep's prolificacy which is influenced by several genes, one of which is the osteopontin (OPN) gene. Thus, this study aimed to determine the effect of genetic variation within the OPN gene on Awassi ewe prolificacy. Genomic DNA was extracted from 123 single-progeny ewes and 109 twin ewes. Polymerase chain reaction (PCR) was used to amplify 4 sequence fragments (289, 275, 338, and 372 bp), representing exons 4, 5, 6, and 7 of the OPN gene. A 372 bp amplicon was identified with 3 different genotypes: TT, TC, and CC. Sequence analysis revealed a novel mutation in TC genotypes p.Q>R234. Statistical analysis revealed that the single nucleotide polymorphism (SNP) p.Q>R234 was associated with prolificacy. Ewes carrying the p.Q>R234 SNP had significantly (P ⩽ .01) lower litter sizes, twinning rates, and lambing rates, and more days to lambing than those with the TC and TT genotypes. The p.Q>R234 SNP was confirmed to be responsible for lower litter size through logistic regression analysis. From these results, we can conclude that the missense variant p.Q>R234 adversely affects the traits of interest and shows that the p.Q>R234 SNP negatively influences the prolificacy of Awassi sheep. Based on this study, it is evident that ewes in this population carrying the p.Q>R234 SNP have a lower litter size and are less prolific.

Association of birth type and LHX4 gene polymorphism with reproductive hormones, growth hormone, and prolactin in Awassi ewes.

BACKGROUND: LIM homeobox transcription factor 4 (LHX4) is a promising candidate gene for mammalian reproductive traits. LHX4 polymorphism has previously been associated with phenotypic traits in goats and cattle. However, there have been no LHX4 gene polymorphisms identified in Awassi sheep. Therefore, this study investigated the effects of the LHX4 polymorphism on reproductive hormones, growth hormones, and prolactin in Awassi ewes. METHODS AND RESULTS: A total of 232 ewes between the ages of 3 and 4 years were selected for this study (123 single-progeny ewes and 109 twin-producing ewes). Serum was collected to measure reproductive hormones, growth hormone, and prolactin using ELISA kits made by ELK Biotechnology. Genomic DNA was extracted from sheep blood, genotyped, and sequenced to confirm variations in LHX4 (exon 1, 207 bp). Genotyping revealed three genotypes in 207 bp: AA, AG, and GG. Sequence analysis detected a novel mutation in exon 1: 160 A > G. Statistically, the 160 A > G SNP was significantly associated with the phenotypic traits. Ewes carrying AA genotypes had higher estrogen, progesterone, follicle-stimulating hormones/luteinizing hormones, and growth hormone, and lower prolactin levels (65.63 ± 3.84) (pg/mL), (6.67 ± 0.38) (ng/mL), (22.34 ± 1.27) (ng/mL)/(23.89 ± 2.13) (ng/mL), (1.30 ± 0.05) (ng/mL), and (13.16 ± 0.75) (pg/mL), respectively, compared to AG and GG genotypes in the fourth month of twin-pregnant ewes compared to single-pregnant ewes. CONCLUSION: This study suggests that the 160 A > G SNP negatively affects the Awassi sheep's hormone levels. It provides valuable insight into the sheep LHX4 gene, which could be an effective marker in marker-assisted selection.

A novel deleterious oxytocin variant is associated with the lower twinning ratio in Awassi ewes.

This study aimed to assess the possible association of oxytocin (OXT) gene with reproductive traits in two groups of Awassi ewes that differ in their reproductive potentials. Sheep were genotyped using PCR-single-stranded conformation polymorphism approach. Three genotypes were detected in exon 2, CC, CA, and AA, and a novel SNP was identified with a missense effect on oxytocin (c.188C > A → p.Arg55Leu). A significant (p < 0.01) association of p.Arg55Leu with the twinning rate was found as ewes with AA and CA genotypes exhibited, respectively a lower twinning ratio than those with the wild-type CC genotype. The deleterious impact of p.Arg55Leu was demonstrated by all in silico tools that were utilized to assess the effect of this variant on the structure, function, and stability of oxytocin. Molecular docking showed that p.Arg55Leu caused a dramatic alteration in the binding of oxytocin with its receptor and reduced the number of interacted amino acids between them. Our study suggests that ewes with AA and CA genotypes showed a lower reproductive performance due to the presence of p.Arg55Leu, which caused damaging impacts on oxytocin and is binding with the OXT receptor. The utilization of the p.Arg55Leu could be useful for improving Awassi reproductive potential.

Two missense variants of the epidermal growth factor receptor gene are associated with non small cell lung carcinoma in the subjects from Iraq.

BACKGROUND: Lung carcinoma is a foremost cause of cancer-related mortality worldwide. Variable genetic factors are associated with the development of lung cancer. This study was performed to evaluate the possible association of epidermal growth factor receptor (EGFR) gene polymorphisms with non small cell lung carcinoma (NSCLC) in Iraqi population. METHODS: DNA samples were extracted from 100 patients and 100 controls. Four PCR fragments were designed to amplify four high-frequency variants within EGFR, namely rs1050171, rs2072454, rs2227984, and rs2227983. The PCR fragments were genotyped by single-strand conformation polymorphism (SSCP) method, and each genotype was subjected to direct sequencing. RESULTS: Genotyping experiments confirmed the variability of three targeted variants, and logistic regression analysis showed that two of these variants (rs1050171 and rs2227983) tend to exhibit a significant association with NSCLC. Individuals with rs1050171:GA genotype showed a possible association with the increased risk of NSCLC (P = 0.0110; OD 5.2636; Cl95% 1.4630 to 18.9371). Individuals with rs2227983:GG genotype exhibited a potential association with NSCLC (P = 0.0037; OD 5.2683; Cl95% 1.7141 to 16.1919). Linkage disequilibrium analysis showed that the effects of the investigated variants seem to take independent actions, and no haplotype was found to be associated with the high prevalence of NSCLC. CONCLUSIONS: Our collective data indicated that EGFR-rs1050171G/A and EGFR-rs2227983G/G SNPs tend to exert significant and separate associations with the increased risk of NSCLC. However, this study recommends using a broader spectrum of the investigated samples to get further details of both SNPs in terms of their association with the susceptibility to NSCLC.