The Aurora A-HP1γ pathway regulates gene expression and mitosis in cells from the sperm lineage.

BACKGROUND: HP1γ, a well-known regulator of gene expression, has been recently identified to be a target of Aurora A, a mitotic kinase which is important for both gametogenesis and embryogenesis. The purpose of this study was to define whether the Aurora A-HP1γ pathway supports cell division of gametes and/or early embryos, using western blot, immunofluorescence, immunohistochemistry, electron microscopy, shRNA-based knockdown, site-directed mutagenesis, and Affymetrix-based genome-wide expression profiles. RESULTS: We find that the form of HP1γ phosphorylated by Aurora A, P-Ser83 HP1γ, is a passenger protein, which localizes to the spermatozoa centriole and axoneme. In addition, disruption in this pathway causes centrosomal abnormalities and aberrations in cell division. Expression profiling of male germ cell lines demonstrates that HP1γ phosphorylation is critical for the regulation of mitosis-associated gene expression networks. In female gametes, we observe that P-Ser83-HP1γ is not present in meiotic centrosomes of M2 oocytes, but after syngamy, it becomes detectable during cleavage divisions, coinciding with early embryonic genome activation. CONCLUSIONS: These results support the idea that phosphorylation of HP1γ by Aurora A plays a role in the regulation of gene expression and mitotic cell division in cells from the sperm lineage and in early embryos. Combined, this data is relevant to better understanding the function of HP1γ in reproductive biology.

Progesterone support for frozen embryo transfer: intramuscular versus vaginal suppository demonstrates no difference in a cohort.

OBJECTIVE: To evaluate pregnancy rates based on the route of progesterone replacement in frozen embryo transfer (FET) cycles. STUDY DESIGN: A randomized controlled trial and retrospective analysis. In the randomized group 76 FET cycles were randomized. In the retrospective group 508 FET cycles were reviewed. Intramuscular (IM) proges-erone in oil 100 mg daily or oral micronized progesterone prior to transfer followed by compounded vaginal proges-erone 200 mg 3 times daily (OV). The main outcome measure was the clinical pregnancy rate (CPR). RESULTS: Baseline characteristics did not vary be-ween groups in either cohort. In the randomized group there were no significant differences in CPR (31.43% vs. 21.05%) or live birth rate (LBR) (31.43% vs. 18.92%) for IM and OV progesterone replacement, respectively. In the retrospective cohort patients there wore also no significant differences in CPR (35.56% vs. 32.35%) or LBR (32.23% vs. 28.51%)f or the IM and OVp rogester-ne replacement groups, respectively. CONCLUSION: This study demonstrates that either OV or IM progesterone is effective for luteal phase support for FETs.

Fertility drug use and the risk of ovarian tumors in infertile women: a case-control study.

OBJECTIVE: To assess the influence of infertility and fertility drugs on risk of ovarian tumors. DESIGN: Case-control study (Mayo Clinic Ovarian Cancer Study). SETTING: Ongoing academic study of ovarian cancer. PATIENT(S): A total of 1,900 women (1,028 with ovarian tumors and 872 controls, frequency matched on age and region of residence) who had provided complete information in a self-report questionnaire about history of infertility and fertility drug use. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Effect of infertility history, use of fertility drugs and oral contraception, and gravidity on the risk of ovarian tumor development, after controlling for potential confounders. RESULT(S): Among women who had a history of infertility, use of fertility drugs was reported by 44 (24%) of 182 controls and 38 (17%) of 226 cases. Infertile women who used fertility drugs were not at increased risk of developing ovarian tumors compared with infertile women who did not use fertility drugs; the adjusted odds ratio was 0.64 (95% CI, 0.37, 1.11). The findings were similar when stratified by gravidity and when analyzed separately for borderline versus invasive tumors. CONCLUSION(S): We found no statistically significant association between fertility drug use and risk of ovarian tumors. Further larger, prospective studies are needed to confirm this observation.

Variability in protein quality used for embryo culture: embryotoxicity of the stabilizer octanoic acid.

OBJECTIVE: To screen human serum albumin (HSA) preparations for toxicity and investigate causes of variation. DESIGN: Experimental laboratory study. SETTING: University-based laboratory. ANIMAL(S): FVB and CF1 mice crossed to create embryos used in experiments. INTERVENTION(S): Mouse embryo assay performed with 5% or 15% HSA (100 mg/mL albumin) from three samples from three separate manufacturers (A, B, C). MAIN OUTCOME MEASURE(S): Blastocyst rates calculated at 96 hours of culture (experiments repeated in triplicate). RESULT(S): The HSA preparations were desalted to remove stabilizers added during HSA processing, then mass spectrometry was used to determine the relative variation in stabilizer concentrations; the effect of the stabilizer octanoic acid on embryo development was tested. At 5% HSA, all samples had blastocyst rates ≥ 70%; at 15% HSA, the blastocyst rates for samples B and C were <50%. Desalting did not affect sample B but did improve the blastocyst rates of sample C. Mass spectrometry revealed high levels of octanoic acid in sample C compared with sample A. The addition of octanoic acid to sample A produced toxicity similar to sample C. CONCLUSION(S): The stabilizer octanoic acid varies by lot and inhibits embryo development. Because octanoic acid is known to cause disruptions in mitochondrial bioenergetics, reduce intracellular pH, and induce oxidative damage in peripheral tissues, its use in embryo culture should be monitored and limited.

Culture systems: mineral oil overlay.

Mineral oil overlay microdrop is commonly used during in vitro fertilization (IVF) procedures. Though mineral oil appears homogeneous, it is an undefined product that can vary in quality. Here, we describe the history, chemistry, processing, and optimal use of mineral oil for IVF and embryo culture.

Sperm morphology: classification drift over time and clinical implications.

OBJECTIVE: To assess sperm morphology with Tygerberg (strict) and World Health Organization (WHO) 3rd criteria for intrauterine inseminations (IUI) between two eras to determine if there was a difference in pregnancy rates. DESIGN: Retrospective study. SETTING: Academic institution. PATIENT(S): 127 couples with 290 IUI treatments during 1996-97 (era 1) and 133 couples with 317 IUI treatments during 2005-06 (era 2). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Pregnancy rates per cycle and couple. RESULT(S): Average sperm morphology was higher in era 1 than era 2 for both WHO 3rd (37 ± 13% vs. 23 ± 10%) and strict criteria (8.0 ± 5.0% vs. 4.0 ± 3.0%). Pregnancy rates per cycle were 5.9% versus 19.8% in era 1 and 16.7% versus 19.3% in era 2 for couples with WHO 3rd morphology <30% or ≥30%, respectively. Pregnancy rates per cycle were 2.7% versus 15.0% in era 1 and 13.3% versus 14.7% in era 2 for couples with strict morphology ≤4% or >4%, respectively. CONCLUSION(S): There was a strong relationship between morphology and IUI outcome in era 1 that was not present in era 2. These results suggest that classification drift increased the percentage of men diagnosed with teratozoospermia and resulted in a loss of predictive value.