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Comment |
Genomewide discovery and classification of candidate ovarian fertility genes in the mouse. Gallardo TD et al. Female infertility syndromes are among the most prevalent chronic health disorders in women, but their genetic basis remains unknown because of uncertainty regarding the number and identity of ovarian factors controlling the assembly, preservation, and maturation of ovarian follicles. To systematically discover ovarian fertility genes en masse, we employed a mouse model (Foxo3) in which follicles are assembled normally but then undergo synchronous activation. We developed a microarray-based approach for the systematic discovery of tissue-specific genes and, by applying it to Foxo3 ovaries and other samples, defined a surprisingly large set of ovarian factors (n = 348, approximately 1% of the mouse genome). This set included the vast majority of known ovarian factors, 44% of which when mutated produce female sterility phenotypes, but most were novel. Comparative profiling of other tissues, including microdissected oocytes and somatic cells, revealed distinct gene classes and provided new insights into oogenesis and ovarian function, demonstrating the utility of our approach for tissue-specific gene discovery. This study will thus facilitate comprehensive analyses of follicle development, ovarian function, and female infertility. This is an oocyte-specific gene.
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Mutations |
3 mutations
Species: human
Mutation name: None
type: naturally occurring
fertility: subfertile
Comment: Exome sequencing reveals SYCE1 mutation associated with autosomal recessive primary ovarian insufficiency. Vries LD 2014 et al.
Context: Primary ovarian insufficiency (POI) is caused by ovarian follicle depletion or follicle dysfunction. The phenotypic spectrum ranges from absence of pubertal maturation to early menopause. Genes involved in essential steps in chromosome synapsis and recombination during meiosis, such as synaptonemal complex central element 1 (SYCE1), have been shown to cause POI in animal models. We describe for the first time a homozygous mutation in SYCE1 in humans. Objective: To identify the genetic cause of POI in an Israeli Arab family with a consanguineous pedigree. Design and Setting: Family-based genetic study conducted at a tertiary medical center. Patients: Two daughters of consanguineous parents (first cousins) from a 13-member family were diagnosed with POI. Genotyping was performed in the index patients, their parents, and four unaffected siblings. Intervention: DNA from the affected sisters was subjected to whole-exome sequencing. The genotypes of interest were confirmed, and genotypes of the additional family members were determined by Sanger sequencing. Genotyping was also performed in 90 ethnically matched control individuals. Results: A nonsense homozygous mutation (c.613C>T) was identified in the SYCE1 gene in both affected sisters. The parents and three brothers were heterozygous for the mutation, and an unaffected sister did not carry the mutation. The mutation was not identified in the DNA samples from the 90 control subjects. Conclusion: Given the known function of the SYCE1 gene, we suggest that the nonsense mutation identified accounts for the POI phenotype. These results highlight the importance of the synaptonemal complex and meiosis in ovarian function.
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Species: mouse
Mutation name: None
type: null mutation
fertility: infertile - ovarian defect
Comment: Mutation of the mouse Syce1 gene disrupts synapsis and suggests a link between synaptonemal complex structural components and DNA repair. Bolcun-Filas E 2009 et al.
In mammals, the synaptonemal complex is a structure required to complete crossover recombination. Although suggested by cytological work, in vivo links between the structural proteins of the synaptonemal complex and the proteins of the recombination process have not previously been made. The central element of the synaptonemal complex is traversed by DNA at sites of recombination and presents a logical place to look for interactions between these components. There are four known central element proteins, three of which have previously been mutated. Here, we complete the set by creating a null mutation in the Syce1 gene in mouse. The resulting disruption of synapsis in these animals has allowed us to demonstrate a biochemical interaction between the structural protein SYCE2 and the repair protein RAD51. In normal meiosis, this interaction may be responsible for promoting homologous synapsis from sites of recombination.Both male and female Syce1 -/- mice were infertile. Syce1 -/- ovaries were minute, and Syce1 -/- testes were only 20 to 30% the size of wildtype testes. In Syce1 -/- ovary and testis, meiosis appeared to be arrested at prophase I.
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Species: human
Mutation name:
type: naturally occurring
fertility: subfertile
Comment: Array-CGH diagnosis in ovarian failure: identification of new molecular actors for ovarian physiology. Jaillard S et al. (2016) Ovarian failure (OF) is considered premature if it occurs before the age of 40. This study investigates the genetic aetiology underlying OF in women under the age of 40 years. We conducted an experimental prospective study performing all genome microarrays in 60 patients younger than 40 years presenting an OF revealed by a decrease of circulating Anti-Müllerian Hormone (AMH) and leading to an oocyte donation program. We identified nine significant copy number variations (CNVs) including candidate genes potentially implicated in reproductive function. These genes are principally involved in cell division and chromosome segregation (SYCE1, CLASP1, CENP-A, CDC16), in ciliary development and/or function (RSPH1, KIF24), are linked with known gonadal genes or expressed in female genital tract (CSMD1, SEMA6D, KIAA1324). Our data strengthen the idea that microarrays should be used in combination with karyotype for aetiological assessment of patients with OF. This analysis may have a therapeutic impact as the identification of new molecular actors for gonadal development or ovarian physiology is useful for the prediction of an ovarian reserve decline and makes possible preventive fertility preservation.//////////////////
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