Testing a candidate meiotic drive locus identified by pool sequencing.

Meiotic drive biases the transmission of alleles in heterozygous individuals, such that Mendel's law of equal segregation is violated. Most examples of meiotic drive have been discovered over the past century based on causing sex ratio distortion or the biased transmission of easily scoreable genetic markers that were linked to drive alleles. More recently, several approaches have been developed that attempt to identify distortions of Mendelian segregation genome wide. Here, we test a candidate female meiotic drive locus in Drosophila melanogaster, identified previously as causing a ∼54:46 distortion ratio using sequencing of large pools of backcross progeny. We inserted fluorescent visible markers near the candidate locus and scored transmission in thousands of individual progeny. We observed a small but significant deviation from the Mendelian expectation; however, it was in the opposite direction to that predicted based on the original experiments. We discuss several possible causes of the discrepancy between the 2 approaches, noting that subtle viability effects are particularly challenging to disentangle from potential small-effect meiotic drive loci. We conclude that pool sequencing approaches remain a powerful method to identify candidate meiotic drive loci but that genotyping of individual progeny at early developmental stages may be required for robust confirmation.

Maternal and neonatal complications during delivery according to passive versus active second stage in woman with medical conditions (ComPActSS).

Background: The incidence of serious complications during vaginal delivery with a passive second stage in women with medical conditions is unknown. Methods: Our retrospective cohort study with matched groups (pairing 1 passive with 2 active second stage) included women who had a medical delivery plan from the high risk obstetric team at our center. The primary outcome was a composite of major maternal and neonatal complications. Results: The primary outcome occurred in 50% (12/24) of women in the passive group versus 35.4% (17/48) (p = 0.24) in the active group. In the passive group, we observed a longer passive second stage of labor (28 vs. 8 min, p < 0.001), a tendency towards more assisted vaginal births (29.2% vs. 12.5%, p = 0.08), and more traumatic deliveries (16.7% vs. 0%, p = 0.012). Conclusion: The higher proportion of complications in women who had a passive second stage should encourage physicians to make this recommendation only in selected cases.

Deletion of protein tyrosine phosphatase SHP-1 restores SUMOylation of podocin and reverses the progression of diabetic kidney disease.

Both clinical and experimental data suggest that podocyte injury is involved in the onset and progression of diabetic kidney disease (DKD). Although the mechanisms underlying the development of podocyte loss are not completely understood, critical structural proteins such as podocin play a major role in podocyte survival and function. We have reported that the protein tyrosine phosphatase SHP-1 expression increased in podocytes of diabetic mice and glomeruli of patients with diabetes. However, the in vivo contribution of SHP-1 in podocytes is unknown. Conditional podocyte-specific SHP-1-deficient mice (Podo-SHP-1-/-) were generated to evaluate the impact of SHP-1 deletion at four weeks of age (early) prior to the onset of diabetes and after 20 weeks (late) of diabetes (DM; Ins2+/C96Y) on kidney function (albuminuria and glomerular filtration rate) and kidney pathology. Ablation of the SHP-1 gene specifically in podocytes prevented and even reversed the elevated albumin/creatinine ratio, glomerular filtration rate progression, mesangial cell expansion, glomerular hypertrophy, glomerular basement membrane thickening and podocyte foot process effacement induced by diabetes. Moreover, podocyte-specific deletion of SHP-1 at an early and late stage prevented diabetes-induced expression of collagen IV, fibronectin, transforming growth factor-ß, transforming protein RhoA, and serine/threonine kinase ROCK1, whereas it restored nephrin, podocin and cation channel TRPC6 expression. Mass spectrometry analysis revealed that SHP-1 reduced SUMO2 post-translational modification of podocin while podocyte-specific deletion of SHP-1 preserved slit diaphragm protein complexes in the diabetic context. Thus, our data uncovered a new role of SHP-1 in the regulation of cytoskeleton dynamics and slit diaphragm protein expression/stability, and its inhibition preserved podocyte function preventing DKD progression.

Optimal management of post-discharge postpartum hypertensive disorders of pregnancy: a quality improvement initiative.

Introduction: Postpartum hypertensive disorders of pregnancy occur in 2-5% of pregnancies. It is a major cause of urgent postpartum consultation and is associated with life-threatening complications. Our objective was to evaluate if local management of postpartum hypertensive disorders of pregnancy was congruent with expert recommendations. Methods: We conducted a quality improvement initiative through a retrospective single-centre cross-sectional study. All women over 18-year-old consulting emergently for hypertensive disorders of pregnancy in the first six weeks postpartum, from 2015 to 2020, were eligible. Results: We included 224 women. Optimal management of postpartum hypertensive disorders of pregnancy was observed in 65.0%. While diagnosis and laboratory work-up were excellent, adequate blood pressure surveillance and recommendations upon discharge of an outpatient postpartum episode (69.7%) did not meet expectations. Conclusion: Efforts should be targeted to improve discharge recommendations on optimal blood pressure surveillance after delivery for women at risk for hypertensive disorders of pregnancy and for postpartum hypertensive disorders of pregnancy in women treated as outpatients.

Transcriptional and metabolomic investigation of the stress response in snow crab during simulated transport condition (Chionoecetes opilio).

The molecular mechanisms underlying the stress response are poorly described in crustaceans. This includes the snow crab (Chionoecetes opilio), a commercially important stenotherm species distributed throughout the northern hemisphere. A better understanding of the stress response in C. opilio is desperately needed for commercial and conservation purposes. The purpose of this study was to investigate the transcriptional and metabolomic response of C. opilio exposed to stressors. Crabs were randomly assigned to 24 or 72 h treatment groups where they were exposed to conditions simulating live transport (handling and air exposure). A control group was kept in cold (2 °C) and well­oxygenated saltwater. The hepatopancreas of the crabs was sampled to perform RNA-sequencing and high-performance chemical isotope labeling metabolomics. Differential gene expression analyses showed that classic crustaceans' stress markers, such as crustacean hyperglycemic hormones and heat shock proteins, were overexpressed in response to stressors. Tyrosine decarboxylase was also up-regulated in stressed crabs, suggesting an implication of the catecholamines tyramine and octopamine in the stress response. Deregulated metabolites revealed that low oxygen was an important trigger in the stress response as intermediate metabolites of the tricarboxylic acid cycle (TCA) accumulated. Lactate, which accumulated unevenly between crabs could potentially be used to predict mortality. This study provides new information on how stressors affect crustaceans and provides a basis for the development of stress markers in C. opilio.

Enhanced SHP-1 Expression in Podocyturia Is Associated with Kidney Dysfunction in Patients with Diabetes.

Background: Diabetic kidney disease (DKD) remains the leading cause of end stage kidney disease worldwide. Despite significant advances in kidney care, there is a need to improve noninvasive techniques to predict the progression of kidney disease better for patients with diabetes. After injury, podocytes are shed in urine and may be used as a biologic tool. We previously reported that SHP-1 is upregulated in the kidney of diabetic mice, leading to podocyte dysfunction and loss. Our objective was to evaluate the expression levels of SHP-1 in urinary podocytes and kidney tissues of patients with diabetes. Methods: In this prospective study, patients with and without diabetes were recruited for the quantification of SHP-1 in kidney tissues, urinary podocytes, and peripheral blood monocytes. Immunochemistry and mass spectrometry techniques were applied for kidney tissues. Urinary podocytes were counted, and expression of SHP-1 and podocyte markers were measured by quantitative PCR. Results: A total of 66 participants (diabetic n=48, nondiabetic n=18) were included in the analyses. Diabetes was associated with increased SHP-1 expression in kidney tissues (P=0.03). Nephrin and podocin mRNA was not significantly increased in urinary podocytes from patients with diabetes compared with those without diabetes, whereas levels of SHP-1 mRNA expression significantly correlated with HbA1c and estimated glomerular filtration rate (eGFR). Additionally, follow-up (up to 2 years post recruitment) evaluation indicated that SHP-1 mRNA expression continued to increase with eGFR decline. Conclusions: Levels of SHP-1 in urinary podocytes may serve as an additional marker of glomerular disease progression in this population.

Reduction of DUSP4 contributes to podocytes oxidative stress, insulin resistance and diabetic nephropathy.

Podocytes are insulin-sensitive cells, and their loss is critical in diabetic nephropathy (DN) progression that could lead to end-stage kidney disease. We have previously shown that decreased DUSP4 expression caused elevated JNK phosphorylation in the diabetic kidney and worsened DN characteristics. Yet, the role of DUSP4 in diabetic podocyte insulin resistance and the progression of DN remains unclear. Here, we report that HG-exposed podocytes exhibited reduced DUSP4 expression, increased phosphorylation of JNK and serine 307 of IRS1 as well as Nox4 expression, while decreasing insulin signaling actions. DUSP4 overexpression, JNK and Nox1/4 inhibition prevented HG-induced serine 307 phosphorylation of IRS1 and restored insulin actions. Diabetic mice showed renal dysfunction and insulin resistance, characteristics that were exacerbated in diabetic DUSP4 deficient mice due to Nox1/4 upregulation. Thus, our results demonstrated that diabetes-induced reduction of DUSP4 leads to JNK activation and elevated Nox4 expression, which contributes to podocyte dysfunction, insulin resistance and progression of DN.

Synchrony of biomarker variability indicates a critical transition: Application to mortality prediction in hemodialysis.

Critical transition theory suggests that complex systems should experience increased temporal variability just before abrupt state changes. We tested this hypothesis in 763 patients on long-term hemodialysis, using 11 biomarkers collected every two weeks and all-cause mortality as a proxy for critical transitions. We find that variability-measured by coefficients of variation (CVs)-increases before death for all 11 clinical biomarkers, and is strikingly synchronized across all biomarkers: the first axis of a principal component analysis on all CVs explains 49% of the variance. This axis then generates powerful predictions of mortality (HR95 = 9.7, p < 0.0001, where HR95 is a scale-invariant metric of hazard ratio; AUC up to 0.82) and starts to increase markedly ∼3 months prior to death. Our results provide an early warning sign of physiological collapse and, more broadly, a quantification of joint system dynamics that opens questions of how system modularity may break down before critical transitions.

Guideline No. 426: Hypertensive Disorders of Pregnancy: Diagnosis, Prediction, Prevention, and Management.

OBJECTIVE: This guideline was developed by maternity care providers from obstetrics and internal medicine. It reviews the diagnosis, evaluation, and management of the hypertensive disorders of pregnancy (HDPs), the prediction and prevention of preeclampsia, and the postpartum care of women with a previous HDP. TARGET POPULATION: Pregnant women. BENEFITS, HARMS, AND COSTS: Implementation of the recommendations in these guidelines may reduce the incidence of the HDPs, particularly preeclampsia, and associated adverse outcomes. EVIDENCE: A comprehensive literature review was updated to December 2020, following the same methods as for previous Society of Obstetricians and Gynaecologists of Canada (SOGC) HDP guidelines, and references were restricted to English or French. To support recommendations for therapies, we prioritized randomized controlled trials and systematic reviews (if available), and evaluated substantive clinical outcomes for mothers and babies. VALIDATION METHODS: The authors agreed on the content and recommendations through consensus and responded to peer review by the SOGC Maternal Fetal Medicine Committee. The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, along with the option of designating a recommendation as a "good practice point." See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and conditional [weak] recommendations).The Board of the SOGC approved the final draft for publication. INTENDED USERS: All health care providers (obstetricians, family doctors, midwives, nurses, and anesthesiologists) who provide care to women before, during, or after pregnancy.

Directive clinique no 426 : Troubles hypertensifs de la grossesse : Diagnostic, prédiction, prévention et prise en charge.

OBJECTIF: La présente directive a été élaborée par des fournisseurs de soins de maternité en obstétrique et en médecine interne. Elle aborde le diagnostic, l'évaluation et la prise en charge des troubles hypertensifs de la grossesse, la prédiction et la prévention de la prééclampsie ainsi que les soins post-partum des femmes avec antécédent de trouble hypertensif de la grossesse. POPULATION CIBLE: Femmes enceintes. BéNéFICES, RISQUES ET COûTS: La mise en œuvre des recommandations de la présente directive devrait réduire l'incidence des troubles hypertensifs de la grossesse, en particulier la prééclampsie, et des issues défavorables associées. DONNéES PROBANTES: La revue exhaustive de la littérature a été mise à jour en tenant compte des nouvelles données probantes jusqu'en décembre 2020 et en suivant la même méthodologie que pour la précédente directive de la Société des obstétriciens et gynécologues du Canada (SOGC) sur les troubles hypertensifs de la grossesse. La recherche s'est limitée aux articles publiés en anglais ou en français. Les recommandations relatives aux traitements s'appuient d'abord sur les essais cliniques randomisés et les revues systématiques (lorsque disponibles), ainsi que sur l'évaluation des résultats cliniques substantiels chez les mères et les bébés. MéTHODES DE VALIDATION: Les auteurs se sont entendus sur le contenu et les recommandations par consensus et ont répondu à l'examen par les pairs du comité de médecine fœto-maternelle de la SOGC. Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant le cadre méthodologique d'évaluation, de développement et d'évaluation (GRADE) et se sont gardé l'option de désigner certaines recommandations par la mention « bonne pratique ¼. Voir l'annexe A en ligne (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et conditionnelles [faibles]). Le conseil d'administration de la SOGC a approuvé la version définitive aux fins de publication. PROFESSIONNELS CIBLES: Tous les fournisseurs de soins de santé (obstétriciens, médecins de famille, sages-femmes, infirmières et anesthésistes) qui prodiguent des soins aux femmes avant, pendant ou après la grossesse.

Guideline No. 426: Hypertensive disorders of pregnancy: diagnosis, prediction, prevention, and management

This guideline was developed by maternity care providers from obstetrics and internal medicine. It reviews the diagnosis, evaluation, and management of the hypertensive disorders of pregnancy (HDPs), the prediction and prevention of preeclampsia, and the postpartum care of women with a previous HDP. Implementation of the recommendations in these guidelines may reduce the incidence of the HDPs, particularly preeclampsia, and associated adverse outcomes. A comprehensive literature review was updated to December 2020, following the same methods as for previous Society of Obstetricians and Gynaecologists of Canada (SOGC) HDP guidelines, and references were restricted to English or French. To support recommendations for therapies, we prioritized randomized controlled trials and systematic reviews (if available), and evaluated substantive clinical outcomes for mothers and babies. The authors agreed on the content and recommendations through consensus and responded to peer review by the SOGC Maternal Fetal Medicine Committee. The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, along with the option of designating a recommendation as a "good practice point." See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and conditional [weak] recommendations).The Board of the SOGC approved the final draft for publication. All health care providers (obstetricians, family doctors, midwives, nurses, and anesthesiologists) who provide care to women before, during, or after pregnancy.

New Perspectives on the Evolution of Within-Individual Genome Variation and Germline/Soma Distinction.

Genomes can vary significantly even within the same individual. The underlying mechanisms are manifold, ranging from somatic mutation and recombination, development-associated ploidy changes and genetic bottlenecks, over to programmed DNA elimination during germline/soma differentiation. In this perspective piece, we briefly review recent developments in the study of within-individual genome variation in eukaryotes and prokaryotes. We highlight a Society for Molecular Biology and Evolution 2020 virtual symposium entitled "Within-individual genome variation and germline/soma distinction" and the present Special Section of the same name in Genome Biology and Evolution, together fostering cross-taxon synergies in the field to identify and tackle key open questions in the understanding of within-individual genome variation.

Pregnancy-associated pelvic vein thrombosis: Insights from a multicenter case series.

BACKGROUND: Pelvic vein thrombosis (PVT) is a rare complication of pregnancy that can lead to life-threatening complications, such as pulmonary embolism (PE). OBJECTIVE: To describe characteristics of PVT and its treatment in pregnancy in the province of Quebec, Canada. PATIENTS/METHODS: We developed a province-wide case series of PVT in pregnancy including four tertiary care centers and the Registry of Rare Diseases of the Groupe d'Étude en Médecine Obstétricale du Québec. Using diagnostic codes, we included cases with confirmed PVT on imaging during pregnancy or within 6 weeks postpartum from July 2003 to June 2018. RESULTS: A total of 47 cases were identified. PVT diagnosis was generally made in the early postpartum period (median of 9 [interquartile range (IQR) 4.5-12] days postpartum). Most PVT (94%) included in this series were symptomatic. Women presented primarily with abdominal pain (77%) and fever (55%), often prolonged despite antibiotics (mean 4.45 ± 2.39 days, with 39% having fever for more than 5 days). The most common risk factor was surgery (57%) and peripartum infections (54%). Thirty-eight (83%) women received antibiotics and 41 (89%) were anticoagulated. Three cases of PE (7%) occurred concomitantly, 11% of women required intensive care, and 19% had inferior vena cava (IVC) clot extension. The episode resulted in prolonged hospitalization (median 6 [IQR 3-10.75] days), with 48% being hospitalized more than 7 days. CONCLUSION: Symptomatic PVT has significant clinical implications with prolonged fever and risks of extension in the IVC and PE, leading to prolonged hospitalization including in the intensive care unit. Therapeutic anticoagulation and antibiotics, when infection is documented, should be considered for management.

Prediction of Mortality in Hemodialysis Patients Using Moving Multivariate Distance.

There is an increasingly widespread use of biomarkers in network physiology to evaluate an organism's physiological state. A recent study showed that albumin variability increases before death in chronic hemodialysis patients. We hypothesized that a multivariate statistical approach would better allow us to capture signals of impending physiological collapse/death. We proposed a Moving Multivariate Distance (MMD), based on the Mahalanobis distance, to quantify the variability of the multivariate biomarker profile as a whole from one visit to the next. Biomarker profiles from a visit were used as the reference to calculate MMD at the subsequent visit. We selected 16 biomarkers (of which 11 are measured every 2 weeks) from blood samples of 763 chronic kidney disease patients hemodialyzed at the CHUS hospital in Quebec, who visited the hospital regularly (∼every 2 weeks) to perform routine blood tests. MMD tended to increase markedly preceding death, indicating an increasing intraindividual multivariate variability presaging a critical transition. In survival analysis, the hazard ratio between the 97.5th percentile and the 2.5th percentile of MMD reached as high as 21.1 [95% CI: 14.3, 31.2], showing that higher variability indicates substantially higher mortality risk. Multivariate approaches to early warning signs of critical transitions hold substantial clinical promise to identify early signs of critical transitions, such as risk of death in hemodialysis patients; future work should also explore whether the MMD approach works in other complex systems (i.e., ecosystems, economies), and should compare it to other multivariate approaches to quantify system variability.

Rapid evolution at the Drosophila telomere: transposable element dynamics at an intrinsically unstable locus.

Drosophila telomeres have been maintained by three families of active transposable elements (TEs), HeT-A, TAHRE, and TART, collectively referred to as HTTs, for tens of millions of years, which contrasts with an unusually high degree of HTT interspecific variation. While the impacts of conflict and domestication are often invoked to explain HTT variation, the telomeres are unstable structures such that neutral mutational processes and evolutionary tradeoffs may also drive HTT evolution. We leveraged population genomic data to analyze nearly 10,000 HTT insertions in 85 Drosophila melanogaster genomes and compared their variation to other more typical TE families. We observe that occasional large-scale copy number expansions of both HTTs and other TE families occur, highlighting that the HTTs are, like their feral cousins, typically repressed but primed to take over given the opportunity. However, large expansions of HTTs are not caused by the runaway activity of any particular HTT subfamilies or even associated with telomere-specific TE activity, as might be expected if HTTs are in strong genetic conflict with their hosts. Rather than conflict, we instead suggest that distinctive aspects of HTT copy number variation and sequence diversity largely reflect telomere instability, with HTT insertions being lost at much higher rates than other TEs elsewhere in the genome. We extend previous observations that telomere deletions occur at a high rate, and surprisingly discover that more than one-third do not appear to have been healed with an HTT insertion. We also report that some HTT families may be preferentially activated by the erosion of whole telomeres, implying the existence of HTT-specific host control mechanisms. We further suggest that the persistent telomere localization of HTTs may reflect a highly successful evolutionary strategy that trades away a stable insertion site in order to have reduced impact on the host genome. We propose that HTT evolution is driven by multiple processes, with niche specialization and telomere instability being previously underappreciated and likely predominant.

Impact of an Educational Pamphlet on Knowledge About Health Risks After Hypertensive Disorders of Pregnancy: A Randomized Trial.

OBJECTIVE: To evaluate patients' knowledge, risk perception, and anxiety about future health risks after an episode of hypertensive disorder of pregnancy (HDP), as well as their satisfaction with an educational pamphlet. METHODS: From January 2016 to June 2017, participants were randomly assigned to one of 2 groups and asked to complete questionnaire #1 (demographics, knowledge, risk perception, anxiety, and satisfaction) after receiving medical counselling at the HDP postpartum clinic. Participants in the intervention group then received the educational pamphlet. One month later, both groups completed the questionnaire again (questionnaire #2). The primary outcome of this study was improvement in the global knowledge score at 1 month, reflecting improved understanding of the health risks of HDP. Secondary outcomes included retention of information, risk perception, satisfaction, and anxiety level. RESULTS: Of 137 eligible women, 57 were randomly assigned to the intervention group and 56, to the control group. Participants in both groups had similar baseline characteristics. Thirteen percent of participants did not complete questionnaire #2. The knowledge score was higher in the intervention group than the control group at 1 month, (88.2%; 95% confidence interval [CI] 26.37-28.32 and 71.3%; 95% CI 20.78-23.45, respectively [P <0.0001]). No difference was seen in anxiety level between the groups (4.0 ± 1.00 vs. 3.8 ± 0.92; P = 0.6746). The intervention group was highly satisfied with the medical counselling they received (5.5 ± 0.84 out 6) and with the pamphlet (5.6 ± 0.66 out 6). CONCLUSION: The educational pamphlet increased women's knowledge about future health risks of HDP without increasing anxiety and it may be helpful in promoting lifestyle changes necessary to modify these risks.

Interlaboratory bias of albuminuria and proteinuria in hypertensive pregnancy.

BACKGROUND: Measurement of proteinuria in women with hypertensive disorders of pregnancy is of major importance in the diagnosis and management of preeclampsia. Urinary protein/creatinine ratio, which is commonly used to detect kidney damage in preeclampsia, suffers from important analytical limitations, including poor harmonization of results between laboratories. Adoption of albuminuria could help reduce interlaboratory bias, since methods used to quantify it are better harmonized. METHODS: A total of 27 urinary samples collected from hypertensive women evaluated for preeclampsia were sent to four different clinical laboratories in Canada. Urinary proteins and albumin as well as urinary creatinine were measured in duplicates in one batch to calculate protein/creatinine (PCR) and albumin/creatinine (ACR) ratio. Statistical analyses were done to evaluate interlaboratory variability of urinary proteins and urinary albumin. RESULTS: Interlaboratory bias for urinary proteins ranged from 64.7% at low concentration to 3.9% at higher concentrations. In contrast, urinary albumin interlaboratory bias ranged from 29.2% to 4% from low to high concentrations. Coefficient of variation for urinary proteins reached a maximum of 91.5% in lower concentration while urinary albumin highest value was 42.7%. When looking at PCR and ACR ratio, eight samples had PCR measurement range that contained the diagnostic threshold used to detect kidney damage in HDP (30 mg/mmol), while only four samples had ACR ratio measurement range that contained the diagnostic threshold used outside of pregnancy in Canada (2 mg/mmol). CONCLUSION: Interlaboratory bias was lower for urinary albumin measurement compared to urinary proteins in hypertensive women evaluated for preeclampsia. Better harmonization with the use of albumin instead of protein measurement would reduce instances where results of different laboratories lead to opposite diagnosis of kidney damage in pregnancy.

Evaluation of Complications in Postpartum Women Receiving Therapeutic Anticoagulation.

OBJECTIVE: To evaluate complications associated with early postpartum therapeutic anticoagulation. METHODS: A multicenter retrospective cohort study was done to evaluate the association between therapeutic anticoagulation postpartum and major complications (hemorrhagic and wound complications). Secondary outcomes included minor complications, risk factors associated with total complications (including the time to therapeutic anticoagulation resumption after delivery) and recurrent thrombotic events within 6 weeks postpartum. RESULTS: From 2003 to 2015, 232 consecutive women were treated with therapeutic anticoagulation within 96 hours postpartum; among those treated, 91 received unfractionated heparin, 138 received low-molecular-weight heparin, and three received other anticoagulants. The primary outcome, a composite of major hemorrhagic complications (requiring transfusion, hospitalization, volume resuscitation, transfer to intensive care unit, or surgery) and major wound complications, occurred in 7 of 83 (8.4%) for cesarean deliveries and 9 of 149 (6.0%) for vaginal deliveries (P=.490). Total complications (including major and minor hemorrhagic and wound complications) occurred in 13 of 83 (15.7%) for cesarean deliveries compared with 9 of 149 (6.0%) for vaginal deliveries (P=.016). When comparing cases associated with and without complications, the median delay before resuming anticoagulation was significantly shorter for both cesarean (12 vs 33 hours, P=.033) and vaginal deliveries (6 vs 19 hours, P=.006). For vaginal deliveries, 8 of 51 (15.7%) women had complications when anticoagulation was started before 9.25 hours postpartum, compared with 1 of 98 (1.0%) when started after 9.25 hours. For cesarean deliveries, 7 of 21 (33.3%) of women experienced complications compared with 6 of 62 (9.7%) if anticoagulation was started before or after 15.1 hours, respectively. Two (0.9%) episodes of venous thromboembolism occurred within 6 weeks postpartum. CONCLUSION: Among postpartum women who received early therapeutic anticoagulation, major complications occurred in 8.4% for cesarean deliveries and 6.0% for vaginal deliveries. Complications were associated with earlier resumption of therapeutic anticoagulation, particularly before 9.25 hours for vaginal deliveries and before 15.1 hours for cesarean deliveries.

Using asexual vertebrates to study genome evolution and animal physiology: Banded (Fundulus diaphanus) x Common Killifish (F. heteroclitus) hybrid lineages as a model system.

Wild, asexual, vertebrate hybrids have many characteristics that make them good model systems for studying how genomes evolve and epigenetic modifications influence animal physiology. In particular, the formation of asexual hybrid lineages is a form of reproductive incompatibility, but we know little about the genetic and genomic mechanisms by which this mode of reproductive isolation proceeds in animals. Asexual lineages also provide researchers with the ability to produce genetically identical individuals, enabling the study of autonomous epigenetic modifications without the confounds of genetic variation. Here, we briefly review the cellular and molecular mechanisms leading to asexual reproduction in vertebrates and the known genetic and epigenetic consequences of the loss of sex. We then specifically discuss what is known about asexual lineages of Fundulus diaphanus x F. heteroclitus to highlight gaps in our knowledge of the biology of these clones. Our preliminary studies of F. diaphanus and F. heteroclitus karyotypes from Porter's Lake (Nova Scotia, Canada) agree with data from other populations, suggesting a conserved interspecific chromosomal arrangement. In addition, genetic analyses suggest that: (a) the same major clonal lineage (Clone A) of F. diaphanus x F. heteroclitus has remained dominant over the past decade, (b) some minor clones have also persisted, (c) new clones may have recently formed, and iv) wild clones still mainly descend from F. diaphanus ♀ x F. heteroclitus ♂ crosses (96% in 2017-2018). These data suggest that clone formation may be a relatively rare, but continuous process, and there are persistent environmental or genetic factors causing a bias in cross direction. We end by describing our current research on the genomic causes and consequences of a transition to asexuality and the potential physiological consequences of epigenetic variation.