scholarly journals A 1-bp deletion in bovine QRICH2 causes low sperm count and immotile sperm with multiple morphological abnormalities

2021 ◽  
Author(s):  
Maya Hiltpold ◽  
Fredi Janett ◽  
Xena Marie Mapel ◽  
Naveen Kumar Kadri ◽  
Zih-Hua Fang ◽  
...  
Keyword(s):  
Premature Termination ◽  
Semen Quality ◽  
Sperm Count ◽  
Sperm Concentration ◽  
Premature Termination Codon ◽  
Termination Codon ◽  
Sequence Variant ◽  
Loss Of Function ◽  
Morphological Abnormalities ◽  
Brown Swiss

Background: Semen quality and male fertility are monitored in artificial insemination bulls to ensure high insemination success rates. Only ejaculates that fulfill minimum quality requirements are processed and eventually used for artificial inseminations. We examined 70,990 ejaculates from 1343 Brown Swiss bulls to identify bulls from which all ejaculates were rejected due to low semen quality. This procedure identified a bull that produced twelve ejaculates with an aberrantly low number of sperm (0.2±0.2 x 109 sperm per ml) which were mostly immotile due to multiple morphological abnormalities. Results: The genome of the bull was sequenced at 12-fold coverage to investigate a suspected genetic cause. Comparing the sequence variant genotypes of the bull with those from 397 fertile bulls revealed a 1-bp deletion in the coding sequence of QRICH2 encoding glutamine rich 2 as a compelling candidate causal variant. The 1-bp deletion causes a frameshift in translation and induces a premature termination codon (ENSBTAP00000018337.1:p.Cys1644AlafsTer52). The analysis of testis transcriptomes from 76 bulls showed that the transcript with the premature termination codon is subjected to nonsense-mediated mRNA decay. The 1-bp deletion resides on a 675 kb haplotype spanning 181 SNPs from the Illumina BovineHD Bead chip. The haplotype segregates at a frequency of 5% in the Brown Swiss cattle population. This analysis also identified another bull that carried the 1-bp deletion in the homozygous state. Semen analyses from the second bull confirmed low sperm concentration and immotile sperm with multiple morphological abnormalities primarily affecting the sperm flagellum and, to a lesser extent, the sperm head. Conclusions: A recessive loss-of-function allele of bovine QRICH2 likely causes low sperm concentration and immotile sperm with multiple morphological abnormalities. Routine sperm analyses unambiguously identify homozygous bulls. A direct gene test can be implemented to monitor the frequency of the undesired allele in cattle populations.

Premature Termination Codon Mutations in Chronic Lymphocytic Leukemia (CLL): Identification of Potential Tumor Suppressors in CLL Including E-Cadherin.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2935-2935
Author(s):  
Sanjai Sharma ◽  
Alan Lichtenstein
Keyword(s):  
Tumor Suppressor ◽  
Premature Termination ◽  
Premature Termination Codon ◽  
Lymphocytic Leukemia ◽  
Termination Codon ◽  
Loss Of Function ◽  
Rt Pcr ◽  
Fold Induction ◽  
Potential Tumor Suppressor ◽  
E Cadherin

Abstract The acquisition of a premature termination codon (PTC) is a mutation that results in premature termination of transcription and degradation of the RNA by the non-sense mediated decay (NMD) pathway. This results in loss of expression of the allele, which harbors the PTC and is frequently the “second hit” in the loss of function of tumor suppressor genes. The NMD pathway can be blocked by protein translation inhibitors like emetine resulting in accumulation of abnormal truncated transcripts with PTC. By combining emetine-induced paralysis of the NMD pathway and microarray technology, a large number of genes were screened for the presence of PTCs in chronic lymphocytic leukemia (CLL) cells. Isolated normal peripheral blood B lymphocytes from two volunteers and five CLL samples were initially analyzed by emetine treatment and microarray. Cells were treated with and without emetine and the RNA was hybridized to Affymetrix 133A chip. Data was analyzed by calculating the fold up-regulation of signal intensity with emetine treatment for all the 23,000 genes on the chip. To take into account any non-specific up-regulation of signal intensity with emetine treatment, the fold induction observed with CLL samples was divided by fold induction obtained from the normal B cell samples to get a Nonsense enrichment index (NEI). Genes with the highest NEI in more than one CLL sample were selected for further study. From this cohort, individual genes were then sequenced and PTC mutations successfully identified in at least three genes; E-cadherin, plakophillin-4 (member of the armadillo family of proteins, a component of desmosomes) and TLE-2 (groucho homolog, a transcriptional repressor that represses transcription by TCF/LEF family members). Because E-cadherin has been described as a potential tumor suppressor whose expression is lost in CLL, we focused on this gene in a bigger cohort of 10 CLL patients. CLL cells were treated with emetine and total RNA was isolated. RNA from emetine treated and untreated cells was analyzed by RT-PCR. Amplified DNA fragments were isolated and sequenced. All 10 patients had an E-cadherin PTC: in 8/10 patients an E-cadherin allele had an exon 11 deletion resulting in premature termination codon and a smaller fragment on the RT-PCR assay. In 2/10 patients, a deletion was identified in exon 13 and 14 both of which were partially deleted resulting in RNA with PTC. Thus in CLL cells from 10 of 10 patients of all clinical stages, an inactivating PTC mutation is present in one of the alleles along with a wild type E-cadherin allele. E-cadherin is a transmembrane glycoprotein that is a component of the adherens junction and plays a role in cell-cell interaction, signaling via the beta-catenin pathway and is a known tumor suppressor. In addition, the plakophillin-4 and TLE-2 genes are negative regulators of the Wnt/catenin pathway and potential loss-of-function PTCs in those genes would further dysregulate this cascade. These data further support the role of E-cadherin as a potential tumor suppressor in CLL and suggest that our novel screen can be used to identify additional tumor suppressors in this disease.

scholarly journals Urinary Bisphenol A, F and S Levels and Semen Quality in Young Adult Danish Men

2021 ◽  
Vol 18 (4) ◽  
pp. 1742
Author(s):  
Thea Emily Benson ◽  
Anne Gaml-Sørensen ◽  
Andreas Ernst ◽  
Nis Brix ◽  
Karin Sørig Hougaard ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Male Fertility ◽  
Parental Education ◽  
Negative Binomial ◽  
Semen Quality ◽  
Sperm Count ◽  
Smoking Status ◽  
Sperm Concentration ◽  
First Trimester ◽  
Negative Binomial Regression Model

Bisphenol A (BPA) is considered an endocrine disruptor and has been associated with deleterious effects on spermatogenesis and male fertility. Bisphenol F (BPF) and S (BPS) are structurally similar to BPA, but knowledge of their effects on male fertility remains limited. In this cross–sectional study, we investigated the associations between exposure to BPA, BPF, and BPS and semen quality in 556 men 18–20 years of age from the Fetal Programming of Semen Quality (FEPOS) cohort. A urine sample was collected from each participant for determination of BPA, BPF, and BPS concentrations while a semen sample was collected to determine ejaculate volume, sperm concentration, total sperm count, sperm motility, and sperm morphology. Associations between urinary bisphenol levels (continuous and quartile–divided) and semen characteristics were estimated using a negative binomial regression model adjusting for urine creatinine concentration, alcohol intake, smoking status, body mass index (BMI), fever, sexual abstinence time, maternal pre–pregnancy BMI, and first trimester smoking, and highest parental education during first trimester. We found no associations between urinary bisphenol of semen quality in a sample of young men from the general Danish population.

scholarly journals Aberrant splicing of the E-cadherin transcript is a novel mechanism of gene silencing in chronic lymphocytic leukemia cells

Blood ◽  
2009 ◽  
Vol 114 (19) ◽  
pp. 4179-4185 ◽  
Author(s):  
Sanjai Sharma ◽  
Alan Lichtenstein
Keyword(s):  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
Premature Termination ◽  
Ectopic Expression ◽  
Premature Termination Codon ◽  
Lymphocytic Leukemia ◽  
Termination Codon ◽  
Nonsense Mediated Decay ◽  
Aberrant Transcript ◽  
E Cadherin

Abstract Premature termination codon (PTC) mutations are due to insertion or deletion of nucleotides causing a frameshift and premature termination codon in RNA. These transcripts are degraded by the nonsense-mediated decay pathway and have a very short half-life. We used a microarray technique to screen for genes that up-regulate their RNA signal upon nonsense-mediated decay pathway blockade in chronic lymphocytic leukemia (CLL) specimens and identified an E-cadherin transcript with PTC. Sequencing revealed an aberrant E-cadherin transcript lacking exon 11, resulting in a frameshift and PTC. The aberrant E-cadherin transcript was also identified in normal B cells, but occurred at a much lower level compared with CLL cells. In CLL specimens, E-cadherin expression was depressed more than 50% in 62% cases (relative to normal B cells). By real-time polymerase chain reaction analysis, the relative amounts of wild-type transcript inversely correlated with amounts of aberrant transcript (P = .018). Ectopic expression of E-cadherin in CLL specimens containing high amounts of aberrant transcript resulted in down-regulation of the wnt–β-catenin pathway reporter, a pathway known to be up-regulated in CLL. Our data point to a novel mechanism of E-cadherin gene inactivation, with CLL cells displaying a higher proportion of aberrant nonfunctional transcripts and resulting up-regulation of the wnt–β-catenin pathway.

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