RESUMO
Controlled ovarian stimulation is tailored to the patient based on clinical parameters but estimating the number of retrieved metaphase II (MII) oocytes is a challenge. Here, we have developed a model that takes advantage of the patient's genetic and clinical characteristics simultaneously for predicting the stimulation outcome. Sequence variants in reproduction-related genes identified by next-generation sequencing were matched to groups of various MII oocyte counts using ranking, correspondence analysis, and self-organizing map methods. The gradient boosting machine technique was used to train models on a clinical dataset of 8,574 or a clinical-genetic dataset of 516 ovarian stimulations. The clinical-genetic model predicted the number of MII oocytes better than that based on clinical data. Anti-Müllerian hormone level and antral follicle count were the two most important predictors while a genetic feature consisting of sequence variants in the GDF9, LHCGR, FSHB, ESR1, and ESR2 genes was the third. The combined contribution of genetic features important for the prediction was over one-third of that revealed for anti-Müllerian hormone. Predictions of our clinical-genetic model accurately matched individuals' actual outcomes preventing over- or underestimation. The genetic data upgrades the personalized prediction of ovarian stimulation outcomes, thus improving the in vitro fertilization procedure.
Assuntos
Hormônio Antimülleriano , Folículo Ovariano , Feminino , Animais , Folículo Ovariano/química , Folículo Ovariano/fisiologia , Hormônio Antimülleriano/genética , Hormônio Antimülleriano/análise , Oócitos/fisiologia , Fertilização in vitro/métodos , Indução da Ovulação/métodosRESUMO
BACKGROUND: In recent years, there has been an increasing interest in SSBs because they find numerous applications in diverse molecular biology and analytical methods. RESULTS: We report the characterization of single-stranded DNA binding proteins (SSBs) from the thermophilic bacteria Thermotoga maritima (TmaSSB) and Thermotoga neapolitana (TneSSB). They are the smallest known bacterial SSB proteins, consisting of 141 and 142 amino acid residues with a calculated molecular mass of 16.30 and 16.58 kDa, respectively. The similarity between amino acid sequences of these proteins is very high: 90% identity and 95% similarity. Surprisingly, both TmaSSB and TneSSB possess a quite low sequence similarity to Escherichia coli SSB (36 and 35% identity, 55 and 56% similarity, respectively). They are functional as homotetramers containing one single-stranded DNA binding domain (OB-fold) in each monomer. Agarose mobility assays indicated that the ssDNA-binding site for both proteins is salt independent, and fluorescence spectroscopy resulted in a size of 68 ± 2 nucleotides. The half-lives of TmaSSB and TneSSB were 10 h and 12 h at 100°C, respectively. When analysed by differential scanning microcalorimetry (DSC) the melting temperature (Tm) was 109.3°C and 112.5°C for TmaSSB and TneSSB, respectively. CONCLUSION: The results showed that TmaSSB and TneSSB are the most thermostable SSB proteins identified to date, offering an attractive alternative to TaqSSB and TthSSB in molecular biology applications, especially with using high temperature e. g. polymerase chain reaction (PCR).
Assuntos
Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Thermotoga maritima/química , Thermotoga neapolitana/química , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Clonagem Molecular , DNA Bacteriano/genética , DNA de Cadeia Simples/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/isolamento & purificação , Regulação Bacteriana da Expressão Gênica , Temperatura Alta , Dados de Sequência Molecular , Peso Molecular , Reação em Cadeia da Polimerase , Domínios e Motivos de Interação entre Proteínas , Estabilidade Proteica , Análise de Sequência de Proteína , Cloreto de Sódio , Espectrometria de Fluorescência , Thermotoga maritima/genética , Thermotoga neapolitana/genéticaRESUMO
The thermophilic bacterium Thermoanaerobacter tengcongensis has two single-stranded DNA-binding (SSB) proteins, designated TteSSB2 and TteSSB3. In a SSB complementation assay in Escherichia coli, only TteSSB3 took over the in vivo function of EcoSSB. We have cloned the ssb genes obtained by PCR and have developed E. coli overexpression systems. The TteSSB2 and TteSSB3 consist of 153 and 150 amino acids with a calculated molecular mass of 17.29 and 16.96 kDa, respectively. They are the smallest known bacterial SSB proteins. The homology between amino acid sequences of these proteins is 40% identity and 53% similarity. They are functional as homotetramers, with each monomer encoding one single-stranded DNA binding domain (OB-fold). In fluorescence titrations with poly(dT), both proteins bind single-stranded DNA with a binding site size of about 40 nt per homotetramer. Thermostability with half-life of about 30 s at 95 degrees C makes TteSSB3 similar to the known SSB of Thermus aquaticus (TaqSSB). The TteSSB2 was fully active even after 6 h incubation at 100 degrees C. Here, we show for the first time paralogous thermostable homotetrameric SSBs, which could be an attractive alternative for known homodimeric thermostable SSB proteins in their applications for molecular biology methods and analytical purposes.
