Induction of somatic cell haploidy by premature cell division.

Canonical mitotic and meiotic cell divisions commence with replicated chromosomes consisting of two sister chromatids. Here, we developed and explored a model of premature cell division, where nonreplicated, G0/G1-stage somatic cell nuclei are transplanted to the metaphase cytoplasm of mouse oocytes. Subsequent cell division generates daughter cells with reduced ploidy. Unexpectedly, genome sequencing analysis revealed proper segregation of homologous chromosomes, resulting in complete haploid genomes. We observed a high occurrence of somatic genome haploidization in nuclei from inbred genetic backgrounds but not in hybrids, emphasizing the importance of sequence homology between homologs. These findings suggest that premature cell division relies on mechanisms similar to meiosis I, where genome haploidization is facilitated by homologous chromosome interactions, recognition, and pairing. Unlike meiosis, no evidence of recombination between somatic cell homologs was detected. Our study offers an alternative in vitro gametogenesis approach by directly reprogramming diploid somatic cells into haploid oocytes.

Unhealthy air quality secondary to wildfires is associated with lower blastocyst yield.

OBJECTIVE: To study the impact of unhealthy air quality from the 2020 Oregon wildfires on outcomes for patients undergoing in vitro fertilization (IVF) treatment. DESIGN: A retrospective cohort study. SETTING: A university-based fertility clinic. PATIENTS: Subjects were undergoing IVF treatment from the 6 weeks preceding the wildfires through a 10-day exposure period. Cohorts were classified on the basis of whether subjects experienced patient and/or laboratory exposure to unhealthy air quality. Patient exposure was defined as at least 4 days of ovarian stimulation overlapping with the exposure, and laboratory exposure was defined as at least 2 days of IVF treatment and embryogenesis overlapping with the exposure. The unexposed cohort consisted of remaining subjects without defined exposure, with cycles in the 6 weeks preceding the wildfires. As some subjects had dual exposure and appeared in both patient and laboratory exposure cohorts, each cohort was separately compared with the unexposed control cohort. INTERVENTION: A 10-day period of unhealthy air quality caused by smoke plumes from a wildfire event. MAIN OUTCOME MEASURES: The primary outcome was the blastulation rate. Secondary outcomes included fertilization rate, number of blastocysts obtained, and cycles with no blastocysts frozen or transferred. RESULTS: Sixty-nine subjects underwent ovarian stimulation and IVF treatment during the 6 weeks preceding the wildfires through the 10-day period of unhealthy air quality. Of these, 15 patients were in the laboratory exposure cohort, 16 were in the patient exposure cohort, and 44 were unexposed. Six subjects appeared in both laboratory and patient exposure cohorts. Although neither exposure cohort had significantly decreased blastulation rate compared with the unexposed, the median number of blastocysts obtained was significantly lower in the laboratory exposure cohort than the unexposed group (2 [range 0-14] vs. 4.5 [range 0-21], respectively). The laboratory exposure cohort had significantly more cycles with no blastocysts obtained (3/15 [20%] vs. 1/44 [2%]). There were no significant differences in IVF treatment outcomes between patient exposure and unexposed cohorts. These findings persisted after controlling for age. There were no significant differences in pregnancy outcomes observed after embryo transfer between the exposure group and the unexposed group. CONCLUSION: For a cohort of patients undergoing IVF treatment, an acute episode of outside wildfire smoke exposure during fertilization and embryogenesis was associated with decreased blastocyst yield.

Strengthening the Reproductive Endocrinology and Infertility Curriculum Through Three Interactive Cases.

Introduction: Improved reproductive endocrinology and infertility (REI) curricula are needed to address educational deficiencies both at our institution and on a national level. To improve REI education for OB/GYN residents and medical students, we developed and piloted a curriculum with in-person and virtual flexibility. Methods: We developed three clinical vignettes for a facilitator-led case-based discussion among OB/GYN residents: two office cases and one emergency scenario. Cases were evaluated by content experts and tested before implementation. Pre- and postsurveys included both multiple-choice questions on content and a Likert-scale self-assessment of comfort, satisfaction, and knowledge. Postsurveys were administered immediately postintervention and at a delayed interval. Responses were compared using paired t tests and McNemar tests. Results: Eighteen learners (16 OB/GYN residents and two medical students) participated, the majority in person, of whom 17 (94%) completed a postsurvey. Self-rated proficiency in evaluating and managing irregular menses, infertility, and amenorrhea all improved significantly immediately following the intervention (p < .05 for all). Learners reported significantly more knowledge and comfort with REI compared to other subspecialties following the intervention (p < .05). More learners responded correctly to knowledge questions postintervention (p < .05 for questions 1 and 2, p = .16 for question 3). All learners were satisfied with and enjoyed the curriculum. Eight learners completed the delayed postsurvey and showed sustained improvements in knowledge and competence with REI content. Discussion: Facilitator-guided case-based learning was effective in improving learners' confidence, comfort, and knowledge in managing REI conditions, and improvements were sustained following a delayed interval.