Browse
Submit Data
Databases
API
Help

Dataset Information

19 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Identification novel mutations in TUBB8 in female infertility and a novel phenotype of large polar body in oocytes with TUBB8 mutations.

ABSTRACT:

Purpose

We aimed to identify novel variants in TUBB8 and corresponding new abnormal phenotypes in oocytes/fertilization/ embryonic development responsible for female infertility.

Methods

Sanger sequencing of TUBB8 was performed in infertile women with abnormalities in oocyte maturation or embryonic development. The effects of the variants were evaluated in patients' oocytes by morphological observations and immunofluorescence.

Results

We identified 34 novel variants of TUBB8 in 51 patients who were diagnosed with abnormalities in oocyte maturation or early embryonic development. We found a novel phenotype in which large polar bodies were present in three independent patients possibly associated with a recurrent variant. Moreover, we identified a novel type of TUBB8 variant consisting of an in-frame deletion-insertion, which has not been previously reported.

Conclusions

Our present study identified 34 novel variants in TUBB8 in 51 patients. These patients show oocyte maturation arrest, oocytes with large polar body, fertilization failure, early embryonic arrest or embryonic implantation failure. These results expand the kinds of variants and phenotypic spectrum of TUBB8 variants with regard to female infertility.

SUBMITTER: Zhao L

PROVIDER: S-EPMC7468027 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

The comprehensive variant and phenotypic spectrum of TUBB8 in female infertility.

Project description:PurposeTUBB8 is a gene that is frequently analysed in the genetic diagnosis of female infertility; 102 variants of this gene have been identified. However, the evaluation of its pathogenicity and the resulting phenotypes vary. Here, we aimed to identify novel TUBB8 variants as well as to summarize the reported variants and phenotypes in order for them to be included in genetic counselling analyses.MethodsWe performed whole exome sequencing to screen for candidate variants in 100 infertile female subjects and 100 controls who were able to conceive naturally. All variants were confirmed by Sanger sequencing. The effects of the variants in oocytes/arrested embryos were assessed by morphological observations, polar body biopsies, and chromosome analysis. A molecular modelling analysis was used to evaluate the possible effects of variants on protein secondary structure.ResultsWe identified 29 TUBB8 variants, of which 20 were novel and five were maternally inherited. We identified three of a total of six recurrent variants that were specific for complete cleavage failure. Moreover, we obtained evidence that TUBB8 variants with large polar bodies had chromosome segregation errors.ConclusionsOur study expands the spectrum of TUBB8 variants, particularly for embryonic arrest. Together with the extant knowledge of TUBB8 variants, this study provides a foundation for the genetic counselling of female infertility.

| S-EPMC8490578 | biostudies-literature

The comprehensive mutational and phenotypic spectrum of TUBB8 in female infertility.

Project description:Human oocyte maturation is a precondition for fertilization and ensuing embryonic development. Previously, we identified TUBB8 variants as a genetic determinant of human oocyte maturation arrest and showed that these variants cause variable and mixed phenotypes in oocyte maturation and early embryo development. We also estimated that rare inherited or de novo variants in the TUBB8 gene accounted for 30% of individuals in a small cohort of patients affected by oocyte maturation arrest. In the present study, we recruited a further 87 patients from unrelated families diagnosed with oocyte maturation or early embryonic arrest and identified 30 patients carrying TUBB8 variants. The corresponding phenotypes not only include oocyte maturation arrest, failure of fertilization, and early embryonic arrest, but also extend to the new phenotype of failure of embryo implantation. These observations provide the most detailed mutational and phenotypic spectrum of TUBB8, further extend the spectrum of variants and dysfunctional oocyte and embryo phenotypes caused by TUBB8 variants, and confirm previous findings for a critical role of TUBB8 during oocyte maturation and early embryonic development. Thus, TUBB8 mutation screening might not only be a genetic diagnostic marker for patients with oocyte maturation arrest, but might also have clinical implications for evaluating the competence of patients' functional oocytes with first polar body (PB1).

| S-EPMC6336793 | biostudies-literature

Mutations in TUBB8 cause a multiplicity of phenotypes in human oocytes and early embryos.

Project description:BackgroundTUBB8 is a primate-specific β-tubulin isotype whose expression is confined to oocytes and the early embryo. We previously found that mutations in TUBB8 caused oocyte maturation arrest. The objective was to describe newly discovered mutations in TUBB8 and to characterise the accompanying spectrum of phenotypes and modes of inheritance.Methods and resultsPatients with oocyte maturation arrest were sequenced with respect to TUBB8. We investigated the effects of identified mutations in vitro, in cultured cells and in mouse oocytes. Seven heterozygous missense and two homozygous mutations were identified. These mutations cause a range of folding defects in vitro, different degrees of microtubule disruption upon expression in cultured cells and interfere to varying extents in the proper assembly of the meiotic spindle in mouse oocytes. Several of the newly discovered TUBB8 mutations result in phenotypic variability. For example, oocytes harbouring any of three missense mutations (I210V, T238M and N348S) could extrude the first polar body. Moreover, they could be fertilised, although the ensuing embryos became developmentally arrested. Surprisingly, oocytes from patients harbouring homozygous TUBB8 mutations that in either case preclude the expression of a functional TUBB8 polypeptide nonetheless contained identifiable spindles.ConclusionsOur data substantially expand the range of dysfunctional oocyte phenotypes incurred by mutation in TUBB8, underscore the independent nature of human oocyte meiosis and differentiation, extend the class of genetic diseases known as the tubulinopathies and provide new criteria for the qualitative evaluation of meiosis II (MII) oocytes for in vitro fertilization (IVF).

| S-EPMC5035199 | biostudies-literature

Functional Haploid Human Oocytes Generated from Polar Body Genomes

Project description:This SuperSeries is composed of the SubSeries listed below.

2016-12-07 | GSE79310 | GEO

Functional Human Oocytes Generated by Transfer of Polar Body Genomes.

Project description:Oocyte defects lie at the heart of some forms of infertility and could potentially be addressed therapeutically by alternative routes for oocyte formation. Here, we describe the generation of functional human oocytes following nuclear transfer of first polar body (PB1) genomes from metaphase II (MII) oocytes into enucleated donor MII cytoplasm (PBNT). The reconstructed oocytes supported the formation of de novo meiotic spindles and, after fertilization with sperm, meiosis completion and formation of normal diploid zygotes. While PBNT zygotes developed to blastocysts less frequently (42%) than controls (75%), genome-wide genetic, epigenetic, and transcriptional analyses of PBNT and control ESCs indicated comparable numbers of structural variations and markedly similar DNA methylation and transcriptome profiles. We conclude that rescue of PB1 genetic material via introduction into donor cytoplasm may offer a source of oocytes for infertility treatment or mitochondrial replacement therapy for mtDNA disease.

| S-EPMC5218919 | biostudies-literature

Functional Haploid Human Oocytes Generated from Polar Body Genomes (RNA-Seq)

2016-12-07 | GSE79309 | GEO

Functional Haploid Human Oocytes Generated from Polar Body Genomes (Bisulfite-Seq)

2016-12-07 | GSE79300 | GEO

Identification and rescue of a novel TUBB8 mutation that causes the first mitotic division defects and infertility.

Project description:PurposeTubulin beta eight class VIII (TUBB8) is essential for oogenesis, fertilization, and pre-implantation embryo development in human. Although TUBB8 mutations were recently discovered in meiosis-arrested oocytes of infertile females, there is no effective therapy for this gene mutation caused infertility. Our study aims to further reveal the infertility-causing gene mutations in the patient's family and to explore whether the infertility could be rescued by optimizing the conditions of embryo culture and finally achieve the purpose of making the patient pregnant.MethodsWhole-exome sequence analysis and Sanger sequencing were performed on patients' family members to screen and identify candidate mutant genes. Construction of plasmids, in vitro transcription, microinjection of disease-causing gene cRNA, and immunofluorescence staining were used to recapitulate the infertility phenotype observed in patients and to understand the pathogenic principles. Simultaneously, overexpression of mutant and wild-type cRNA of the candidate gene in mouse oocytes at either germinal vesicle (GV) or metaphase II (MII) stage was performed in the rescue experiment.ResultsWe first identified a novel heritable TUBB8 mutation (c.1041C>A: p.N347K) in the coding region which specifically affects the first mitosis and causes the developmental arrest of early embryos in a three-generation family. We further demonstrated that TUBB8 mutation could lead to abnormal spindle assemble. And moreover, additional expression of wild-type TUBB8 cRNA in the mouse oocytes in which the mutant TUBB8 were expressed can successfully rescue the developmental defects of resulting embryo and produce full-term offspring.ConclusionsOur study not only defines a novel mutation of TUBB8 causing the early cleavage arrest of embryos, but also provides an important basis for treating such female infertility in the future.

| S-EPMC7642063 | biostudies-literature

Identification of Novel Mutations in <i>CDC20</i>: Expanding the Mutational Spectrum for Female Infertility.

Project description:Oocyte maturation and fertilization are fundamental processes for successful human reproduction, and abnormalities in these processes will cause infertility. Recently, we identified biallelic mutations in CDC20 that are responsible for human oocyte maturation arrest, fertilization failure, and early embryonic development arrest. In this study, we screened for further CDC20 mutations in a new cohort of patients with abnormalities in oocyte maturation, fertilization, and early embryonic development. Through whole-exome sequencing, we identified the four novel mutations c.887G > A (p. Arg296Gln), c.964C > T (p.Arg322∗), c.1155G > C (p.Trp385Cys), and c.330 + 1G > A (p. Glu111Ilefs∗36) and one previously reported mutation c.965G > A (p.Arg322Gln) in CDC20 in four infertile individuals from three independent families. The patients had different phenotypes of oocyte maturation arrest and fertilization failure resulting from the different mutations. This study confirms our previous research and expands the spectrum of known mutations in CDC20, providing new evidence supporting the function of CDC20 in the genetic etiology of female infertility characterized by oocyte maturation arrest and fertilization failure.

| S-EPMC8063106 | biostudies-literature

Homozygous Mutations in WEE2 Cause Fertilization Failure and Female Infertility.

Project description:Fertilization is a fundamental process of development and is a prerequisite for successful human reproduction. In mice, although several receptor proteins have been shown to play important roles in the process of fertilization, only three genes have been shown to cause fertilization failure and infertility when deleted in vivo. In clinical practice, some infertility case subjects suffer from recurrent failure of in vitro fertilization and intracytoplasmic sperm injection attempts due to fertilization failure, but the genetic basis of fertilization failure in humans remains largely unknown. Wee2 is a key oocyte-specific kinase involved in the control of meiotic arrest in mice, but WEE2 has not been associated with any diseases in humans. In this study, we identified homozygous mutations in WEE2 that are responsible for fertilization failure in humans. All four independent affected individuals had homozygous loss-of-function missense mutations or homozygous frameshift protein-truncating mutations, and the phenotype of fertilization failure was shown to follow a Mendelian recessive inheritance pattern. All four mutations significantly decreased the amount of WEE2 protein in vitro and in affected individuals' oocytes in vivo, and they all led to abnormal serine phosphorylation of WEE2 and reduced tyrosine 15 phosphorylation of Cdc2 in vitro. In addition, injection of WEE2 cRNA into affected individuals' oocytes rescued the fertilization failure phenotype and led to the formation of blastocysts in vitro. This work presents a novel gene responsible for human fertilization failure and has implications for future therapeutic treatments for infertility cases.

| S-EPMC5985286 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data