The BMP-15 gene is located on the X-chromosome and using Northern blot analysis BMP-15 mRNA is locally expressed within the ovaries in oocytes only after they have started to undergo the primary stages of development.

[6] Intracellular processing then leads to the removal of the proregion, leaving the biologically active mature region to perform the functions.

[7] Most active BMPs have a common structure, in which they contain 7 cysteines, 6 of which form three intramolecular disulphide bonds and the seventh being involved in the formation of dimers with other monomers.

[8] In most of the BMP family heterodimers and homodimers form as the seventh cysteine is involved in the formation of a covalent bond, leading the dimerization.

[9] These point mutations result in higher ovulation rates and larger litter sizes than sheep strains with a wildtype BMP-15 genotype.

[9] Sheep carrying homozygous alleles for the Inverdale and Hanna BMP-15 mutations are infertile, as they have streak ovaries and the primary stage of folliculogenesis is inhibited.

[9] The homozygous mutant mice did not suffer from reduced folliculogenesis or impacted follicle progression, unlike in the sheep homologue knockout experiments.

[9] In slight contrast to the reports on sheep, the women in this study were heterozygous for the BMP-15 mutation but exhibited streak ovaries, a phenotype very similar to the one seen in homozygous mutant ewes.

[9] The sisters presented with primary amenorrhea, showing that BMP-15 is also vital to normal human female fertility, concordant with the sheep model.

[13] BMP-15 defects have been implicated in female sterility, Polycystic Ovary Syndrome (PCOS), primary ovarian insufficiency (POI) and endometriosis.

Depending on the chromosomal mutation, BMP-15 gene dosage varies and impacts ovarian development in Turner syndrome patients.