Identification of the first homozygous 1-bp deletion in GDF9 gene leading to primary ovarian insufficiency by using targeted massively parallel sequencing.

Targeted massively parallel sequencing (TMPS) has been used in genetic diagnosis for Mendelian disorders. In the past few years, the TMPS has identified new and already described genes associated with primary ovarian insufficiency (POI) phenotype. Here, we performed a targeted gene sequencing to find a genetic diagnosis in idiopathic cases of Brazilian POI cohort. A custom SureSelectXT DNA target enrichment panel was designed and the sequencing was performed on Illumina NextSeq sequencer. We identified 1 homozygous 1-bp deletion variant (c.783delC) in the GDF9 gene in 1 patient with POI. The variant was confirmed and segregated using Sanger sequencing. The c.783delC GDF9 variant changed an amino acid creating a premature termination codon (p.Ser262Hisfs*2). This variant was not present in all public databases (ExAC/gnomAD, NHLBI/EVS and 1000Genomes). Moreover, it was absent in 400 alleles from fertile Brazilian women screened by Sanger sequencing. The patient's mother and her unaffected sister carried the c.783delC variant in a heterozygous state, as expected for an autosomal recessive inheritance. Here, the TMPS identified the first homozygous 1-bp deletion variant in GDF9. This finding reveals a novel inheritance pattern of pathogenic variant in GDF9 associated with POI, thus improving the genetic diagnosis of this disorder.

Aluminum as an endocrine disruptor in female Nile tilapia (Oreochromis niloticus).

The effects of aluminum on plasma ion, lipid, protein and steroid hormone concentration were evaluated in Oreochromis niloticus broodstock females. Lipid and protein concentrations from the gonads and liver were also measured. Experiments were performed at neutral and acidic water pH. Four groups of fish were tested for 96h: 1) control conditions at neutral water pH; 2) control conditions at acidic water pH (CTR-Ac); 3) aluminum at neutral water pH (Al-N); and 4) aluminum at acidic water pH (Al-Ac). Aluminum and acidic water pH exposure caused no ionoregulatory disturbances. Total lipid concentration increased in the mature gonads and decreased in the liver, suggesting an acceleration of lipid mobilization to the ovaries in animals exposed to aluminum. However, a decreased protein concentration in ovaries was also observed. Exposure of control fish to acidic water pH caused an increased concentration of plasma 17alpha-hydroxyprogesterone. However, females exposed to aluminum at acidic water pH showed a decreased of plasma 17alpha-hydroxyprogesterone and cortisol. No differences in plasma 17beta-estradiol were observed. The physiological mechanisms underlying the disturbances observed are discussed focusing on reproduction. We suggest that aluminum can be considered an endocrine disrupting compound in mature O. niloticus females.

Patterns of oocyte development in natural habitat and captive Salminus hilarii Valenciennes, 1850 (Teleostei: Characidae).

Fecundity and oocyte development in Salminus hilarii female brood stock were analyzed with the aim of investigating the impact of migration impediment on oogenesis. Histological analyses of the ovaries were performed in adult females caught in two different environments--the Tietê River (natural) and captivity--and the gonadossomatic index, oocyte diameter and fecundity determined. Five germ cell development stages (oogonium, perinucleolar, cortical alveoli, vitellogenic, ripe) and two other structures (postovulatory follicles and atretic oocytes) were observed in females caught in the river. Captive animals lacked the ripe oocytes and postovulatory follicles and had a relatively higher number of atretic oocytes. Females in captivity are known to produce larger oocytes, and they release fewer eggs in each spawn (absolute fecundity) when compared with animals that are able to migrate. Our results suggest that the Tietê River is undergoing alterations which are being reflected in the reproductive performance of S. hilarii, mainly due to the presence of atretic oocytes in females caught in the river. The lack of postovulatory follicles and ripe oocytes in captive animals reveals that migratory impediment negatively impacts final oocyte maturation. However, the stage of maturation reached is adequate for ovulation induction with hormone manipulation.