The FMR1 gene as regulator of ovarian recruitment and ovarian reserve.

The fragile X mental retardation 1 (FMR1) gene is primarily associated with neuro/psychiatric risks. Recent evidence suggests that the gene also exerts controlling functions on follicle recruitment and ovarian reserve (OR). We performed unrestricted Medline and PubMed searches of the medical literature independently under search terms, FMR1 gene, fragile X gene, and in association with premature ovarian aging, primary ovarian insufficiency, occult primary insufficiency, premature ovarian failure, premature menopause, ovarian reserve (OR), diminished ovarian reserve, follicle recruitment and ovarian aging. We also used web-based resources in regards to the FMR1 gene and reviewed additional citations from reviewed publications. Recently published data strongly suggest an independent function of the FMR1 gene on ovaries. This function appears distinct from the gene's neuro/psychiatric effects, associated with a different, and specific, triple nucleotide (CGG) repeat range and characterized by specific genotypes. Ovarian function in all races/ethnicities appears defined by a normal range of 26 to 34 CGG repeats (mean 30), including the reported distribution peak of 29 to 30 repeats in humans and maximal gene translation, reported at 30 repeats. Genotypes, defined by 2 normal count alleles (normal) demonstrate different OR aging patterns from women with 1 (heterozygous) or both alleles outside of range (homozygous). Heterozygous and homozygous genotypes recruit fewer follicles at younger ages, thus preserving OR into advanced age. These observations suggest a direct FMR1 effect on follicular recruitment and OR and, therefore, on women's fecundity.

Primary Ovarian Insufficiency: X chromosome defects and autoimmunity.

Premature ovarian failure (POF) is a primary ovarian defect characterized by absent menarche or premature depletion of ovarian follicles before the age of 40 years. However, in several instances the distinction between definitive or intermittent POF may be difficult on clinical bases, therefore the more appropriate term Primary Ovarian Insufficiency (POI) has been recently proposed and will be used in this review. POI is a heterogeneous disorder affecting approximately 1% of women <40 years. The most severe forms present with absent pubertal development and primary amenorrhea, whereas forms with post-pubertal onset are characterized by disappearance of menstrual cycles (secondary amenorrhea) associated with a defective folliculogenesis. POI is generally characterized by low levels of gonadal hormones (estrogens and inhibins) and high levels of gonadotropins (LH and FSH) (hypergonadotropic amenorrhea). Heterogeneity of POI is reflected by the variety of possible causes, including autoimmunity, toxics, drugs, as well as genetic defects. Several data indicate that POI has a strong genetic component. In this manuscript we discuss the X chromosome abnormalities that are associated with POI.

Generation of polyclonal antiserum for the detection of methylarginine proteins.

This report describes an approach for the study of the biology of methylarginine proteins based on the generation of immunological reagents capable of recognizing the methylarginine status of cellular proteins. Two forms of an immunizing peptide were prepared based upon an amino acid sequence motif found most prevalently among verified dimethylarginine-containing proteins. One form of the peptide was constructed with 7 arginine residues alternating with 8 glycine residues. None of the arginines used in the synthesis were methylated. The alternative form of the peptide was synthesized with the identical repeating GRG sequence, but with asymmetrical dimethylarginine at each arginine residue. A methylarginine-specific antiserum was generated using the latter peptide. ELISA and western blotting of glycine arginine-rich peptides, each synthesized with or without asymmetric dimethylarginine, demonstrate the methyl specificity of the antiserum. The methylarginine-specific antibody co-localizes with the highly methylated native nucleolin protein conspicuously concentrated in the nucleolus. The methylarginine-specific antiserum recognizes a GRG peptide and bacterially expressed RBP16 only after incubation of the peptide or RBP16 with recombinant protein arginine methyltransferase 1, or cell extracts, respectively. Proteins isolated from cells in different developmental states exhibit different patterns of reactivity observed by western blots. Finally, the methylarginine-specific reagent interacts specifically with the methylarginine of cellular hnRNPA1 and human fragile X mental retardation protein expressed in cultured PC12 cells. An immunological reagent capable of detecting the methylarginine status of cellular methylproteins will facilitate the cellular and molecular analysis of protein arginine methylation in a wide variety of research and biomedical applications.