scholarly journals Male Hypogonadism and Germ Cell Loss Caused by a Mutation in Polo-Like Kinase 4

Endocrinology ◽  
2011 ◽  
Vol 152 (10) ◽  
pp. 3975-3985 ◽  
Author(s):  
Rebecca M. Harris ◽  
Jeffrey Weiss ◽  
J. Larry Jameson
Keyword(s):  
Male Infertility ◽  
Germ Cell ◽  
Missense Mutation ◽  
Cell Cycle Progression ◽  
Cell Loss ◽  
Kinase Domain ◽  
Heterozygous Mutation ◽  
Male Hypogonadism ◽  
Testis Size ◽  
Pachytene Spermatocytes

The genetic etiologies of male infertility remain largely unknown. To identify genes potentially involved in spermatogenesis and male infertility, we performed genome-wide mutagenesis in mice with N-ethyl-N-nitrosourea and identified a line with dominant hypogonadism and patchy germ cell loss. Genomic mapping and DNA sequence analysis identified a novel heterozygous missense mutation in the kinase domain of Polo-like kinase 4 (Plk4), altering an isoleucine to asparagine at residue 242 (I242N). Genetic complementation studies using a gene trap line with disruption in the Plk4 locus confirmed that the putative Plk4 missense mutation was causative. Plk4 is known to be involved in centriole formation and cell cycle progression. However, a specific role in mammalian spermatogenesis has not been examined. PLK4 was highly expressed in the testes both pre- and postnatally. In the adult, PLK4 expression was first detected in stage VIII pachytene spermatocytes and was present through step 16 elongated spermatids. Because the homozygous Plk4I242N/I242N mutation was embryonic lethal, all analyses were performed using the heterozygous Plk4+/I242N mice. Testis size was reduced by 17%, and histology revealed discrete regions of germ cell loss, leaving only Sertoli cells in these defective tubules. Testis cord formation (embryonic day 13.5) was normal. Testis histology was also normal at postnatal day (P)1, but germ cell loss was detected at P10 and subsequent ages. We conclude that the I242N heterozygous mutation in PLK4 is causative for patchy germ cell loss beginning at P10, suggesting a role for PLK4 during the initiation of spermatogenesis.

A novel missense mutation of CRYBA1 in a northern Chinese family with inherited coronary cataract with blue punctate opacities

2021 ◽  
pp. 112067212110083
Author(s):  
Shu-Hua Ni ◽  
Juan-Mei Zhang ◽  
Jun Zhao
Keyword(s):  
Missense Mutation ◽  
High Throughput Sequencing ◽  
Bioinformatics Analysis ◽  
Genetic Defect ◽  
Kinase Domain ◽  
Chinese Family ◽  
Heterozygous Mutation ◽  
Scale Invariant ◽  
The Family ◽  
Northern Chinese

Purpose: To demonstrate the underlying genetic defect that contribute to inherited cataract in a northern Chinese pedigree. Methods: The study recruited a family pedigree with a diagnosis of bilateral coronary cataract with blue punctate opacities. Fourteen family members and 100 healthy volunteers were enrolled. DNA sample of the proband in this family were analyzed by high-throughput sequencing, which was then demonstrated by Sanger sequencing in the remained people in the family and 100 controls. The functional effect of mutant genes was investigated via bioinformatics analysis, including Polymorphism Phenotyping version2 (PolyPhen-2), Protein Variation Effect Analyzer (PROVEAN v1.1.3) Scale-Invariant Feature Transform (SIFT), and Mutation Taster. Results: In this three-generation family, a novel heterozygous mutation was found in the kinase domain of CRYBA1 gene (c.340C > T, p.R114C), which was only detected in patients in the family with inherited cataract and were not detected in the remained people in the family nor in normal people. The pathogenic effect of the mutation was verified via bioinformatics analysis. Conclusion: Our study presented the molecular experiments to confirm that a novel missense mutation of c.340 C > T located in exon 4 of CRYBA1 gene results in a bilateral coronary cataract with blue punctate opacities, which enriches the mutation spectrum of CRYBA1 gene in inherited cataract and deepens the understanding of the pathogenesis of inherited cataract.

scholarly journals Splicing mutation in Sbf1 causes nonsyndromic male infertility in the rat

Reproduction ◽  
2016 ◽  
pp. 215-223 ◽  
Author(s):  
František Liška ◽  
Blanka Chylíková ◽  
Michaela Janků ◽  
Ondřej Šeda ◽  
Zdeňka Vernerová ◽  
...  
Keyword(s):  
Male Infertility ◽  
Germ Cell ◽  
Stop Codon ◽  
Premature Stop Codon ◽  
Cell Loss ◽  
Cell Number ◽  
Brown Norway ◽  
Cell Stage ◽  
Charcot Marie Tooth Disease ◽  
Binding Factor

In the inbred SHR/OlaIpcv rat colony, we identified males with small testicles and inability to reproduce. By selectively breeding their parents, we revealed the infertility to segregate as an autosomal recessive Mendelian character. No other phenotype was observed in males, and females were completely normal. By linkage using a backcross with Brown Norway strain, we mapped the locus to a 1.2Mbp segment on chromosome 7, harboring 35 genes. Sequencing of candidate genes revealed a G to A substitution in a canonical ‘AG’ splice site of intron 37 in Sbf1 (SET binding factor 1, alias myotubularin-related protein 5). This leads to either skipping exon 38 or shifting splicing one base downstream, invariantly resulting in frameshift, premature stop codon and truncation of the protein. Western blotting using two anti-Sbf1 antibodies revealed absence of the full-length protein in the mutant testis. Testicles of the mutant males were significantly smaller compared with SHR from 4weeks, peaked at 84% wild-type weight at 6weeks and declined afterward to 28%, reflecting massive germ cell loss. Histological examination revealed lower germ cell number; latest observed germ cell stage were round spermatids, resulting in the absence of sperm in the epididymis (azoospermia). SBF1 is a member of a phosphatase family lacking the catalytical activity. It probably modulates the activity of a phosphoinositol phosphatase MTMR2. Human homozygotes or compound heterozygotes for missense SBF1 mutations exhibit Charcot–Marie–Tooth disease (manifested mainly as progressive neuropathy), while a single mouse knockout reported in the literature identified male infertility as the only phenotype manifestation.

scholarly journals TRIM71 deficiency causes germ cell loss during mouse embryogenesis and promotes human male infertility

2021 ◽  
Author(s):  
Lucia A. Torres-Fernández ◽  
Jana Emich ◽  
Yasmine Port ◽  
Sibylle Mitschka ◽  
Marius Wöste ◽  
...  
Keyword(s):  
Male Infertility ◽  
Germ Cell ◽  
Germ Cells ◽  
Cell Loss ◽  
Seminiferous Tubules ◽  
Obstructive Azoospermia ◽  
Sequencing Analysis ◽  
Mouse Embryogenesis ◽  
Human Male

AbstractMutations affecting the germline can result in infertility or the generation of germ cell tumors (GCT), highlighting the need to identify and characterize the genes controlling the complex molecular network orchestrating germ cell development. TRIM71 is a stem cell-specific factor essential for embryogenesis, and its expression has been reported in GCT and adult mouse testes. To investigate the role of TRIM71 in mammalian germ cell embryonic development, we generated a germline-specific conditional Trim71 knockout mouse (cKO) using the early primordial germ cell (PGC) marker Nanos3 as a Cre-recombinase driver. cKO mice are infertile, with male mice displaying a Sertoli cell-only (SCO) phenotype, which in humans is defined as a specific subtype of non-obstructive azoospermia characterized by the absence of developing germ cells in the testes’ seminiferous tubules. Infertility originates during embryogenesis, as the SCO phenotype was already apparent in neonatal mice. The in vitro differentiation of mouse embryonic stem cells (ESCs) into PGC-like cells (PGCLCs) revealed reduced numbers of PGCLCs in Trim71-deficient cells. Furthermore, in vitro growth competition assays with wild type and CRISPR/Cas9-generated TRIM71 mutant NCCIT cells, a human GCT-derived cell line which we used as a surrogate model for proliferating PGCs, showed that TRIM71 promotes NCCIT cell proliferation and survival. Our data collectively suggest that germ cell loss in cKO mice results from combined defects during the specification and maintenance of PGCs prior to their sex determination in the genital ridges. Last, via exome sequencing analysis, we identified several TRIM71 variants in a cohort of infertile men, including a loss-of-function variant in a patient with SCO phenotype. Our work reveals for the first time an association of TRIM71 variants with human male infertility, and uncovers further developmental roles for TRIM71 in the generation and maintenance of germ cells during mouse embryogenesis.

scholarly journals MC4R mutant mice develop ovarian teratomas

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abdullah An Naser ◽  
Takehiro Miyazaki ◽  
Jun Wang ◽  
Shuji Takabayashi ◽  
Theeranukul Pachoensuk ◽  
...  
Keyword(s):  
Germ Cell ◽  
Missense Mutation ◽  
Congenic Strain ◽  
Genetically Modified ◽  
Primordial Germ Cells ◽  
Cell Formation ◽  
Cell Loss ◽  
Melanocortin 4 Receptor ◽  
Teratoma Formation ◽  
Ovarian Teratomas

AbstractTeratomas in mice, composed of different tissue types, are derived from primordial germ cells (PGCs) in the foetal gonads. The strongest candidate gene in the testicular teratoma locus (Ter) responsible for testicular teratoma formation was identified as mutation in Dnd1, Dnd1R178*. However, the phenotype of mice with a mutated Dnd1 gene was germ cell loss. This suggests that other genes are involved in teratoma formation. Testicular teratomas can also be induced experimentally (experimentally testicular teratomas: ETTs) in 129/Sv mice by transplanting E12.5 foetal testes into adult testes. Previously, we mapped the ett1 locus, which is the locus responsible for ETT formation on chromosome 18. By exome sequence analysis of the 129 and LTXBJ (LT) strains, we identified a missense mutation in the melanocortin 4 receptor (MC4R) gene among 8 genes in the ett1 region. The missense mutation causes a substitution of glycine 25 by serine. Thus, this gene is a candidate for ETT formation. We established the LT-ett1 congenic strain, which introduced the locus responsible for ETT formation genetically into the genomes of a testicular teratoma non-susceptible strain. In this study, we crossed LT-ett1 and a previously established LT-Ter strain to establish the double congenic strain LT-Ter-ett1. Also, we established a strain with a point mutation in the MC4R gene of the LT strain by genome editing, LT-MC4RG25S. Furthermore, double genetically modified strain LT-Ter-MC4RG25S was established to address the relation between Ter and MC4R. Surprisingly, highly developed ovarian teratomas (OTs), instead of testicular teratomas, appeared not only in the LT-Ter-MC4RG25S and LT-MC4RG25S strains but also in the LT-ett1 and LT-Ter-ett1 strains. The incidence of OT formation was high in double genetically modified strains. The results demonstrated that MC4R is one of the genes responsible for OT formation. It was suggested that the effect of the missense mutation in MC4R on teratoma formation was promoted by abnormal germ cell formation by the mutation in DND1.

scholarly journals EAU-verslag Andrologie

2020 ◽  
Vol 10 (S2) ◽  
pp. 20-22
Author(s):  
Marij Dinkelman-Smit
Keyword(s):  
Sexual Dysfunction ◽  
Reproductive Health ◽  
Male Infertility ◽  
Sexual And Reproductive Health ◽  
Male Hypogonadism ◽  
Male Sexual Dysfunction

Samenvatting De EAU guidelines ‘Male infertility, male sexual dysfunction en male hypogonadism’ zijn ondergebracht onder een nieuw panel dat dit jaar de eerste ‘Sexual and Reproductive Health’ richtlijn presenteerde: zeer de moeite waard om te bekijken. Hierna volgt een samenvatting ‘Andrologie en testiculaire kiemceltumor’ uit de EAU20 Virtual.

scholarly journals Drosophila CG2469 Encodes a Homolog of Human CTR9 and Is Essential for Development

2016 ◽  
Vol 6 (12) ◽  
pp. 3849-3857 ◽  
Author(s):  
Dhananjay Chaturvedi ◽  
Mayu Inaba ◽  
Shane Scoggin ◽  
Michael Buszczak
Keyword(s):  
Germ Cell ◽  
Sequence Similarity ◽  
Cell Loss ◽  
Germline Stem Cell ◽  
Cell Nuclei ◽  
Transcriptional Initiation ◽  
Histone Locus Bodies ◽  
Paf1 Complex ◽  
Histone Locus ◽  
Drosophila Cells

Abstract Conserved from yeast to humans, the Paf1 complex participates in a number of diverse processes including transcriptional initiation and polyadenylation. This complex typically includes five proteins: Paf1, Rtf1, Cdc73, Leo1, and Ctr9. Previous efforts identified clear Drosophila homologs of Paf1, Rtf1, and Cdc73 based on sequence similarity. Further work showed that these proteins help to regulate gene expression and are required for viability. To date, a Drosophila homolog of Ctr9 has remained uncharacterized. Here, we show that the gene CG2469 encodes a functional Drosophila Ctr9 homolog. Both human and Drosophila Ctr9 localize to the nuclei of Drosophila cells and appear enriched in histone locus bodies. RNAi knockdown of Drosophila Ctr9 results in a germline stem cell loss phenotype marked by defects in the morphology of germ cell nuclei. A molecular null mutation of Drosophila Ctr9 results in lethality and a human cDNA CTR9 transgene rescues this phenotype. Clonal analysis in the ovary using this null allele reveals that loss of Drosophila Ctr9 results in a reduction of global levels of histone H3 trimethylation of lysine 4 (H3K4me3), but does not compromise the maintenance of stem cells in ovaries. Given the differences between the null mutant and RNAi knockdown phenotypes, the germ cell defects caused by RNAi likely result from the combined loss of Drosophila Ctr9 and other unidentified genes. These data provide further evidence that the function of this Paf1 complex component is conserved across species.

Pyk2 and FAK differentially regulate progression of the cell cycle

2000 ◽  
Vol 113 (17) ◽  
pp. 3063-3072 ◽  
Author(s):  
J. Zhao ◽  
C. Zheng ◽  
J. Guan
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Regulation ◽  
Cell Cycle Progression ◽  
Expression System ◽  
Chimeric Protein ◽  
Kinase Domain ◽  
Cycle Progression ◽  
Erk Activation ◽  
Terminal Domain ◽  
Cycle Regulation

We have previously identified FAK and its associated signaling pathways as a mediator of cell cycle progression by integrins. In this report, we have analyzed the potential role and mechanism of Pyk2, a tyrosine kinase closely related to FAK, in cell cycle regulation by using tetracycline-regulated expression system as well as chimeric molecules. We have found that induction of Pyk2 inhibited G(1) to S phase transition whereas comparable induction of FAK expression accelerated it. Furthermore, expression of a chimeric protein containing Pyk2 N-terminal and kinase domain and FAK C-terminal domain (PFhy1) increased cell cycle progression as FAK. Conversely, the complementary chimeric molecule containing FAK N-terminal and kinase domain and Pyk2 C-terminal domain (FPhy2) inhibited cell cycle progression to an even greater extent than Pyk2. Biochemical analyses indicated that Pyk2 and FPhy2 stimulated JNK activation whereas FAK or PFhy1 had little effect on it, suggesting that differential activation of JNK by Pyk2 may contribute to its inhibition of cell cycle progression. In addition, Pyk2 and FPhy2 to a greater extent also inhibited Erk activation in cell adhesion whereas FAK and PFhy1 stimulated it, suggesting a role for Erk activation in mediating differential regulation of cell cycle by Pyk2 and FAK. A role for Erk and JNK pathways in mediating the cell cycle regulation by FAK and Pyk2 was also confirmed by using chemical inhibitors for these pathways. Finally, we showed that while FAK and PFhy1 were present in focal contacts, Pyk2 and FPhy2 were localized in the cytoplasm. Interestingly, both Pyk2 and FPhy2 (to a greater extent) were tyrosine phosphorylated and associated with Src and Fyn. This suggested that they may inhibit Erk activation in an analogous manner as the mislocalized FAK mutant (Δ)C14 described previously by competing with endogenous FAK for binding signaling molecules such as Src and Fyn. This model is further supported by an inhibition of endogenous FAK association with active Src by Pyk2 and FPhy2 and a partial rescue by FAK of Pyk2-mediated cell cycle inhibition.

Male infertility. More than a statistical risk factor for Germ Cell Tumors?

2000 ◽  
Vol 33 (2) ◽  
pp. 135-139
Author(s):  
H. Büttner ◽  
P. Fornara ◽  
J. Sandmann ◽  
C. Doehn ◽  
D. Jocham
Keyword(s):  
Risk Factor ◽  
Male Infertility ◽  
Germ Cell ◽  
Germ Cell Tumors ◽  
Statistical Risk

The polymorphisms of NR5A1 gene in azoospermic men in Sichuan, China

2020 ◽  
Author(s):  
Lanyue Cui ◽  
Jiaoyu He ◽  
Junhang Deng ◽  
Zhilin Song ◽  
Qiufu Li ◽  
...  
Keyword(s):  
Male Infertility ◽  
Missense Mutation ◽  
Karyotype Analysis ◽  
Semen Analysis ◽  
Transcriptional Regulator ◽  
Organ Development ◽  
Steroidogenic Factor 1 ◽  
Beta Strand ◽  
Susceptibility Factor ◽  
Infertile Men

Abstract Background: Steroidogenic factor 1 (SF1, NR5A1) is a key transcriptional regulator involved in the hypothalamic-pituitary-steroidogenic organ development. Recently, heterozygous mutations in NR5A1 were found may contribute to the male infertility aetiology. Here, we investigated the association of polymorphisms in NR5A1 gene with azoospermic men in Sichuan, China. Methods: We have performed the NR5A1 gene direct secquencing in a cohort of 102 well-characterised idiopathic Chinese azoospermic infertile men versus 103 fertile men, who were selected by Semen analysis, Karyotype analysis and Y-chromosomal AZF deletion screening. We identified two previously described missense p. Results: Gly146Ala (rs1110061; c.437 G>C) and p.Arg313His (c.938G>A), and the frequency of 437C ( [OR] 1.846, 95% [CI] 1.227-2.778, P=0.003), 437GC (OR =1.884 , 95% CI =1.037-3.422 , P =0.037 ) and 437CC (OR =3.586 , 95% CI =1.397-9.206 , P =0.006 ) were found to be increased significantly in azoospermic patients while no mutations in control .Moreover, one novel heterozygous p.Ser322ILe (c.965 G >A) missense mutation was found in 8 patients which highly conserved serine to isoleucine shown in the Beta strand domain on SF-1 protein. Conclusions: This is the first study, according to our knowledge, to investigate the association between the polymorphisms of NR5A1 gene and azoospermic men in China, and these results suggest that the Gly146Ala polymorphism may be a susceptibility factor for the azoospermic men in Sichuan, China.

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