Morbi-Mortality Linked to Unsafe Abortions—Difficulties in Accessing Safe Abortions in Cameroon: Meta-Analysis and Systematic Review

Background: Unsafe abortions are one of the leading causes of maternal mortality, especially in developing countries. In Cameroon, the maternal mortality rate remains high, and the scarcity of data on abortions leads to a lack of solid evidence to advocate on the extent of the abortions related complications. Our objective was to evaluate the unsafe abortions related complications, and to assess the difficulties of accessing safe abortions in our setting. Methods: We carried out a meta-analytic and systematic review in the biomedical databases MEDLINE (Pubmed), Google Scholar and African Journal Online concerning unsafe abortions and/or difficulties in accessing safe abortions in Cameroon. The keywords used for the search are seen in table I. Selection of studies was simultaneously done by two authors. Data were extracted through a form designed on Google Form. We used a random-effect model for proportion estimation, and The I2 and Q statistics to assess the extent of heterogeneity. Results: A total of 430 studies were identified, from which 28 were included and analysed. About 5% (95% CI: 3 - 7) of unsafe abortions leads to death. The contribution of unsafe abortions in maternal deaths was 23% (95% CI: 20 - 27). The rate of severe bleeding and/or anemia were 40% (95% CI: 18 - 63) and the rate of infection was 17% (95% CI: 7 - 28), dominated by pelvic infections, pelviperitonitis, severe sepsis, and septic shock. Case reports described uterine perforations, uterine rupture during the following pregnancy. Abortion was performed in the practitioner’s or patient’s home in 41.4% of cases, in a health center in 35.1% of cases, in a private clinic in 21.2% of cases, drugs selling places and in traditional healer clinics. The restriction of abortion laws, the stigma surrounding abortion and its consequences at any level of the society, lead to the underreporting of unsafe abortions and a deep reluctance to advocate for safe abortion services. Conclusion: The strengthening of awareness campaigns for provider behavior change communication, family planning, the de-stigmatization of abortions, the training of health personnel in post-abortion care, a multidisciplinary and multicentric action would contribute to the reduction in morbidity and mortality due to abortions.

Clandestine Abortions and Its Complications at the University Hospital Center of the Sino-Central African Friendship

Introduction: In developed countries in general and particularly in the Central African Republic, clandestine abortions constitute a real health problem. The aim of our work was to study the method of carrying out clandestine abortions, to describe the profile of the providers and the complications that result from it. Patients and Methods: This was a descriptive cross-sectional study of patients hospitalized at the University Hospital Center for Sino-Central African Friendship (CHUASC) from 2015 to 2019 on 236 cases. Results: We identified a total of 254 patients for 8039 live births in the same period, a frequency of 3.16%. The age of the patients was between 15 years old and 48 years old with an average of 25 years old. Singles accounted for 42.5%. Induced abortions were more performed among students (32.6%) and the unemployed 53.6%. Contraception was used in 11.5% of cases. The methods used were numerous: misoprostol (32%), the traditional method (18%), the mechanical method (50%). In this method, we note the dilation of the cervix by the cassava stem;Hegar’s candles;the probes, which are infusion tubes cut and introduced into the cervix, of which 2 cases had escaped at the level of the uterine muscles and emerged under the skin at the pubis part two years later. The practice of induced abortions in our series was done by medical students in 37.3% followed by unqualified staff in 49.7%. It took place either at home or in centers managed by Non-Governmental Organizations. The aseptic conditions were not perfect. Some patients (43.2%) were aware of the ensuing complications. All complications were present: hemorrhage (60.7%), pelviperitonitis (23.6%), uterine perforation (6.6%), peritonitis (2.8%) and death (2%) related to sepsis. Conclusion: Clandestine abortion remains a real health problem for young Central African women.

Hysteroscopic septum resection in patients with recurrent abortions and infertility

Objective: The aim of this study was to assess the achievement of pregnancy as well as the reproductive outcome after hysteroscopic septum resection in women with recurrent abortions or infertility. Design: retrospective, clinical trial. Setting: University hospitals. Patient(s): Fourty women with a diagnosis of uterine septum who had a history of pregnancy loss or infertility. They were randomized into two groups. Group I includes 18 infertile women and group II includes 22 recurrent miscarriage women. Intervention(s): Hysteroscopic metroplasty was performed on all patients in both groups. Result(s): 40 patients who were diagnosed with a partial septate uteri had hysteroscopic septum resection and were divided into two groups: Group I (18 patients) presented with infertility and Group II (22 patients) with recurrent abortions. The mean post-operative follow up period was 24 months. Group I, 12 patients (66.6%) and Group II, 17 patients (77.2%) achieved pregnancy, with respective abortion rates of 2 (11.1%) and 4 (18.1%). Conclusion(s): Using hysteroscopy to perform metroplasty on septate uteri makes the procedure safer, easier, and less complicated. This procedure is recommended for all cases diagnosed with an uterine septum.

Racial disparity in years of potential life lost to induced abortions

The magnitude of the overall prevalence and racial disparity in induced abortion suggests that it is a major influence on the demographic and socioeconomic composition of the population of the United States (US). However, the years of potential lives averted by induced abortion have not been systematically studied. We applied race-specific intra-uterine death estimates to the induced abortions occurring to non-Hispanic (NH) white and non-Hispanic (NH) black women in the US state of North Carolina in 2008. The resultant estimate of births averted by induced abortion was used to project years of potential life lost. All-cause detailed mortality data were used to compare induced abortion with other contributing causes of years of potential life lost before age 75 (YPLL 75). For NH whites, induced abortions in 2008 contributed 59% of total YPLL 75, and 1.5 times the total YPLL 75 from all other causes combined. For NH blacks, induced abortions in 2008 contributed 76% of total YPLL 75 and 3.2 times the total YPLL 75 from all other causes combined. Induced abortion is the overwhelmingly predominant contributing cause of preventable potential lives lost in the North Carolina population, and NH blacks are disproportionately affected.

Problematic of Clandestine Induced Abortions in Three Maternity Hospitals of Chad

Background: In the world, induced abortion constitutes a preponderant cause of morbidity and maternal mortality, more particularly in developing countries. In these countries, the prevalence of contraception remains low, and situation makes the bed of unwanted pregnancies leading easily to the induced abortions. The objective was to determine frequency of clandestine induced abortions and to know the motivations of women that practice these abortions in order to find a solution to minimize this practice. Patients and method: We conducted a prospective, descriptive and multicenter survey for three months from November 1st, 2015 to January 31st, 2016 achieved at N’Djamena Mother and Child hospital which is national reference structure in terms reproduction health, Moundou Regional Hospital and Abéché Regional Hospital about the epidemiological aspects and complications clandestine induced abortions. The population of survey was constituted of patients admitted in a maternity of these hospitals for clandestine induced abortion. Every patient having practiced a documented induced abortion and having agreed to participate in the survey was included. Results: During the survey period, we recorded 94 cases of clandestine induced abortions among 2759 deliveries giving a frequency of 3.4%. The age group between 20 - 24 years was the most represented with 42.7%. The average age was 25.4 years, with the extremes ranging from 15 to 42 years. Singles (66%) dominated marital status. Sixty patients (63.9%) were of secondary. These patients were for the most part students or pupils (55.3%). Concerning the parity, nulliparous were the most numerous to practice the abortion (40.5%). More than half our patients (58.7%) knew no contraceptive method. The principal reason evoked to realize the abortion was further studies (38.2%). Means of abortion most used was the misoprostol (36 cases that is 38.2%). In this series, we observed 29 cases of complications, which is 30.8%. The complications were dominated by the anaemia (62.1%). Conclusion: The clandestine induced abortion is a frequent situation in the Chad and is cause of numerous complications.

Research Priorities for Preventing Unsafe Abortions in the WHO Africa Region

Background: Unsafe abortion is a commonly neglected sexual and reproductive health and rights issue despite the serious health problems it causes to women and girls in their reproductive ages. It is classified as a main cause of maternal mortality and morbidity. This paper has considered questions that have the greatest potential to successfully reduce unsafe abortions in the resource poor settings. Methods: We adapted the Child Health and Nutrition Research Initiative (CHNRI) to identify and prioritize many competing sexual and reproductive health and rights research ideas that impact the health of the populations. The implementation was done in three phases which included generation and collection of research ideas from various experts virtually in August 2019 consolidation of the potential questions through thematic analysis conducted in September 2019. Finally, scoring and ranking of the research questions was done in a workshop of experts. Results: Out of a list of 45 priority research questions, two questions were ranked the highest scoring 28 out of the possible 30. The research priorities include: “The effectiveness of interventions (e.g. counseling or incentives or home visits) to increase post abortion uptake and continuance”, “Reducing repeat abortion on improving maternal health outcomes” and “Evaluation of community-based awareness programs to reduce unwanted pregnancies and encourage women to seek help early”. Conclusions: Ten key research priorities in preventing unsafe abortion were identified. The priority list covers areas of focus that could effectively impact preventing unsafe abortions while also acting as a knowledge base for researchers, policy makers and other interested stakeholders who would want to invest in this area.

Morbidity and Mortality Linked to Unsafe Abortions in Cameroon—Difficulties in Accessing Safe Abortions: Systematic Review and Meta-Analysis. A Study Proposal

Unsafe abortions constitute a public health problem. It is one of the causes of maternal mortality in the world and particularly in developing countries. Despite the progress made, maternal mortality remains high in Cameroon. The scarcity and disparity of data on abortions lead to a lack of strong evidence to advocate to decision-makers on the extent of the problems associated with abortions in Cameroon. Our objective is to estimate the rates of mortalities and complications related to unsafe abortions, as well as the difficulties of accessing safe abortions in Cameroon. We will carry out a systematic and meta-analytical review in the biomedical databases MEDLINE (Pubmed), Google Scholar and African Journal Online (AJOL) concerning unsafe abortions and/or difficulties in accessing safe abortions in Cameroon, without date or language restriction. Gray literature will be also consulted. Two authors will simultaneously select the studies and data extraction will be done using a Google Form. Proportions will be estimated on a random-effect model. The I2 and Q statistics will be used to assess the extent of heterogeneity across the studies. The outcome of both the quantitative and qualitative parts of the study will be commented. Death and morbidity due to abortions can be prevented. A concerted multidisciplinary and multicentric action would be essential.

The effect of carbapenem resistance in Klebsiellae on infection outcomes in animals and birds

It is often said that the emergence of antimicrobial drug resistance(AMR)in pathogens is the major cause of mortality.In the present study,clinical microbiology data on infections caused by Klebsiella pneumoniae strains and their antimicrobial drug resistance specifically to carbapenems retrieved from Clinical Epidemiology database of the Institute were analysed to determine the impact of carbapenem resistance in Klebsiellae isolated from the clinical samples of veterinary cases and outcome of the infection because in a few recent reports it is claimed that the presence of carbapenem-resistant Klebsiellae is associated with higher mortality in humans due to Klebsiella infections.The retrospective analysis of Klebsiella infections in animals and birds revealed that 21.8%of K.pneumoniae causing pneumonic or septicemic infections were carbapenem-resistant but the carbapenem resistance was not associated with increased numbers of deaths or recovery.It may be probably due to the fact that carbapenem drugs were not used for the treatment of infected animals and carbapenem resistance may not be associated with the lethality potential of Klebsiellae.

Effect of emotion management and nursing on patients with painless induced abortion after operation

BACKGROUND With an estimated 121 million abortions following unwanted pregnancies occurring worldwide each year,many countries are now committed to protecting women’s reproductive rights.AIM To analyze the impact of emotional management and care on anxiety and contraceptive knowledge mastery in painless induced abortion(IA)patients.METHODS This study was retrospective analysis of 84 patients with IA at our hospital.According to different nursing methods,the patients were divided into a control group and an observation group,with 42 cases in each group.Degree of pain,rate of postoperative uterine relaxation,surgical bleeding volume,and postoperative bleeding volume at 1 h between the two groups of patients;nursing satisfaction;and mastery of contraceptive knowledge were analyzed.RESULTS After nursing,Self-Assessment Scale,Depression Self-Assessment Scale,and Hamilton Anxiety Scale scores were 39.18±2.18,30.27±2.64,6.69±2.15,respectively,vs 45.63±2.66,38.61±2.17,13.45±2.12,respectively,with the observation group being lower than the control group(P<0.05).Comparing visual analog scales,the observation group was lower than the control group(4.55±0.22 vs 3.23±0.41;P<0.05).The relaxation rate of the cervix after nursing,surgical bleeding volume,and 1-h postoperative bleeding volumes were 25(59.5),31.72±2.23,and 22.41±1.23,respectively,vs 36(85.7),42.39±3.53,28.51±3.34,respec tively,for the observation group compared to the control group.The observation group had a better nursing situation(P<0.05),and higher nursing satisfaction and contraceptive knowledge mastery scores compared to the control group(P<0.05).CONCLUSION The application of emotional management in postoperative care of IA has an ideal effect.

MiR-142-3p Regulates ILC1s by Targeting HMGB1 via the NF-κB Pathway in a Mouse Model of Early Pregnancy Loss

Objective Innate lymphoid cells(ILCs)are a class of newly discovered immunocytes.Group 1 ILCs(ILC1s)are identified in the decidua of humans and mice.High mobility group box 1(HMGB1)is predicted to be one of the target genes of miR-142-3p,which is closely related to pregnancy-related diseases.Furthermore,miR-142-3p and HMGB1 are involved in regulating the NF-κB signaling pathway.This study aimed to examine the regulatory effect of miR-142-3p on ILC1s and the underlying mechanism involving HMGB1 and the NF-κB signaling pathway.Methods Mouse models of normal pregnancy and abortion were constructed,and the alterations of ILC1s,miR-142-3p,ILC1 transcription factor(T-bet),and pro-inflammatory cytokines of ILC1s(TNF-α,IFN-γand IL-2)were detected in mice from different groups.The targeting regulation of HMGB1 by miR-142-3p in ILC1s,and the expression of HMGB1 in normal pregnant mice and abortive mice were investigated.In addition,the regulatory effects of miR-142-3p and HMGB1 on ILC1s were detected in vitro by CCK-8,Annexin-V/PI,ELISA,and RT-PCR,respectively.Furthermore,changes of the NF-κB signaling pathway in ILC1s were examined in the different groups.For the in vivo studies,miR-142-3p-Agomir was injected in the uterus of abortive mice to evaluate the abortion rate and alterations of ILC1s at the maternal-fetal interface,and further detect the expression of HMGB1,pro-inflammatory cytokines,and the NF-κB signaling pathway.Results The number of ILC1s was significantly increased,the level of HMGB1 was significantly upregulated,and that of miR-142-3p was considerably downregulated in the abortive mice as compared with the normal pregnant mice(all P<0.05).In addition,miR-142-3p was found to drastically inhibit the activation of the NF-κB signaling pathway(P<0.05).The number of ILC1s and the levels of pro-inflammatory cytokines were significantly downregulated and the activation of the NF-κB signaling pathway was inhibited in the miR-142-3p Agomir group(all P<0.05).Conclusion miR-142-3p can regulate ILC1s by targeting HMGB1 via the NF-κB signaling pathway,and attenuate the inflammation at the maternal-fetal interface in abortive mice.

Populational change of CD4^(+)CD25^(+)Treg cells is responsible for the synergistic effect of the combination of RAMP2 with baicalin in treating recurrent spontaneous abortion mouse models

Background: The absence of a safe and effective therapy for recurrent spontaneous abortion due to a maternofetal failure in immunological tolerance remains an intractable clinical obstacle for surgeons. Recently, traditional Chinese medicine has become a feasible alternative for certain diseases, including recurrent spontaneous abortion. However, because of the complex composition of the traditional Chinese medicine formula, its action mechanism remains unclear. Methods: We selected two isolated active ingredients (RAMP and baicalin) from the traditional Chinese medicine formula and used an abortion-prone CBA/J × DBA/2 model to simulate human RSA and compared the changes in fetal resorption rate, Treg cell percentage, and relevant cytokines before and after combination therapy. In addition, The mechanisms were preliminarily discussed using in vitro differentiation models. Results: In CBA/J × DBA/2 abortion-prone mice, the combination therapy resulted in a lower embryo resorption rate compared to that obtained with individual delivery of either RAMP or baicalin, thereby playing an embryo-protective role through the increase in Treg cells for the maintenance of maternal-fetal immune tolerance. In in vitro primary cell differentiation experiments, the concentration of Treg cells significantly increased from 11% to 17.9% after the combination therapy compared to that of the single administration group. Conclusion: the synergistic effects of RAMP and baicalin were responsible for Treg differentiation. The present study provides a solid basis for improving the applicability of traditional Chinese herbs in the treatment of recurrent spontaneous abortion.

Potential and application of abortive transcripts as a novel molecular marker of cancers

Abortive transcript(AT)is a 2-19 nt long non-coding RNA that is produced in the abortive initiation stage.Abortive initiation was found to be closely related to RNA polymerase through in vitro experiments.Therefore,the distribution of AT length and the scale of abortive initiation are correlated to the promoter,discriminator,and transcription initiation sequence,and can be affected by transcription elongation factors.AT plays an important role in the occurrence and development of various diseases.Here we summarize the discovery of AT,the factors responsible for AT formation,the detection methods and biological functions of AT,to provide new clues for finding potential targets in the early diagnosis and treatment of cancers.

Prevalence of Induced Abortion among Female Students in Selected Tertiary Learning Institutions in Gaborone City, Botswana

Induced abortion signifies that pregnancy has been tempered with. Abortion is the removal of an embryo or fetus weighing less than 500 grams from its mother. It can either be spontaneous (unprompted) or induced. Abortion remains one of the leading causes of maternal deaths in developing countries with induced abortion being the key cause. In 2014 from January to August, 9 abortion related deaths occurred in Botswana. There are several reasons female students in tertiary institutions resort to seeking induced abortion which include the socio-demographics like age and socio-economic factors like financial instability. Parental fears, unintended pregnancy and pressure from the partner also force females to terminate pregnancy. Induced abortion has claimed many women’s lives especially in developing countries with very restrictive abortion laws like Botswana as women do not access safe abortion care services. The study intends to establish the determinants of induced abortion among female students in selected tertiary learning institutions in Gaborone City, Botswana. It concentrated primarily on determining the prevalence of induced abortion. This was a descriptive cross-sectional study using both quantitative and qualitative data collection techniques. Systematic random sampling technique was used to come up with 278 participants. Prior to commencement of data collection, all ethical and logistical prerequisites were satisfied. Informed consent was solicited from all the study participants and the purpose of the study was fully explained. A self-administered questionnaire was used to collect data. Microsoft Excel spread sheet was used to code, clean, and enter the data, which was then exported for analysis to the statistical package for social sciences version 24. Frequency distribution tables, percentages graphs, and pie charts were used to illustrate the descriptive information. The study revealed that prevalence of induced abortion among female students in Gaborone City is 7.9%. They even suggested that induced abortion be liberalized. Age was the only socio-demographic factor associated with induced abortion with p = 0.047 using Chi Square test χ2 = 7.609, df = 3. The study findings concluded that female students resort to induced abortion as a result of pressure from both parents and male partners especially when the pregnancy is unintended. The study recommends that the abortion law in Botswana be made liberal to ease access to safe abortion care services. It also recommends that contraceptive commodities should consistently be available in public health facilities.

Patterns of Infertility and Abortion in Saudi Arabia: A Cross-Sectional Study

Background: Infertility and abortion are significant reproductive health concerns globally, impacting individuals' well-being and healthcare systems. In Saudi Arabia, cultural, social, and religious factors influence perceptions and management of these issues, necessitating research to understand the patterns and associated factors. Study Aim: This cross-sectional study aimed to investigate the patterns of infertility and abortion among 458 women in Saudi Arabia, focusing on demographic profiles, reproductive histories, medical conditions, and lifestyle factors. Methodology: Participants were recruited from healthcare facilities, and data on age, BMI, reproductive history, medical conditions, assisted reproduction methods, and lifestyle behaviors were collected. Statistical analyses, including chi-square tests, were conducted to examine associations between variables. Results: The majority of participants were aged 30 - 39 years (47.4%), with 76.9% experiencing secondary infertility. Among those with offspring (76.9%), 31% reported using assisted reproduction methods, primarily ovarian stimulators (54.2%). Abortion history was reported by 39.5% of participants. Significant associations were found between age and infertility type (X2 = 5.8, p = 0.054), having offspring and infertility type (X2 = 458.0, p = 0.001), menstrual irregularity and infertility type (X2 = 11.4, p = 0.001), and abortion history and delayed fertility (X2 = 10.4, p = 0.001). Conclusion: Our study reveals significant associations between demographic, medical, and lifestyle factors with infertility patterns and abortion history among Saudi women. These findings emphasize the need for tailored interventions addressing medical conditions, age-related factors, and access to reproductive healthcare services.

Evaluation of etiological characteristics of Chinese women with recurrent spontaneous abortions： a single-centre study

Background Various etiologies that contribute to the loss of pregnancy have been proposed. Despite the lack of established and uniform screening methods for recurrent pregnancy loss （RPL）, there are several factors considered to be definite （or probable） causes of RPL. Data describing the etiological characteristics of RPL consist almost entirely of Caucasian populations. As we were interested in the Chinese population, the goal of this study was to determine the etiological characteristics of RPL in the Chinese patients.Methods The study was performed retrospectively by analyzing 1122 women with RPL. Patients were divided into three groups according to their number of pregnancy losses. Diagnostic tests included the following 9 critiria： parental genetics, uterine anatomy, autoimmune factors, alloimmune factors, thrombophilic factors, endocrine parameters, genital infection, toxoplasma, rubella, cytomegalovirus, herpes （TORCH） titers and RH blood groups. The criteria for abnormal results were defined before diagnosis.Results We found that 87.1% （977/1122） patients had no more than 3 abnormal aspects, and the proportion of total abnormal results was similar among groups. The prevalence of abnormal results for each test did not differ among groups,except in the cases of parental genetics, uterine anatomy and presence of mixed lymphocyte reaction blocking antibodies （MLR-Bf）. Absence of MLR-Bf, as well as abnormally increased levels of CD3＋CD19＋ and CD56＋CD16＋ cells, was commonly detected in Chinese RPL patients.Conclusion Immunological disorders play an important role in RPL among Chinese patients.

Circulating Antisperm Antibody (ASA) in Women is not Associated with Missed Abortions at the First-trimester Pregnancy

Objective To determine the role of the circulating antisperm antibody （ASA） in the pathogenesis of missed abortion at the first-trimester pregnancy. Methods Sixty-two patients with a history of missed abortion at the first-trimester pregnancy were enrolled into this study. Indirect immunobead test （IBT） was used to measure the circulating ASA levels. Fifty healthy women with the first-trimester pregnancy set as the control. Results No case had the positive level of ASA according to the World Health Organization criteria （50% or more of the motile sperm with immunobead binding）. Only 1 case in patient group and 1 case in the control had 10%-20% of the motile spermatozoa with ASA-IgG bead binding. In both patient and control groups, ASA-IgA was found to be completely negative binding. Conclusion The circulating ASA is not associated with the pathogenesis of missed abortions at the first-trimester pregnancy.

Cytogenetic analysis in 61 couples with spontaneous abortions

Objective To examine the relationship between spontaneous abortion and chromosomal abnormalities.Methods Couples who had one or more consecutive spontaneous abortions and had normal genitals were enrolled for cytogenetic karyotype analysis. Results In the 61 couples, the detected incidence was 11.5%, with five Robertsonian translocations, one reciprocal translocation, and one pericentric inversion of chromosome 7. Conclusion Chromosomal abnormalities may play an important role in fetal wastage.

Efficacy of Single Dose of Mifepristone Combined with Two Doses of Misoprostol in Early Medical Abortions

Objective To study the efficacy of single dose of mifepristone and two doses of misoprostol in women undergoing early medical abortion （EMA） up to 9 weeks of gestation. Methods An audit was performed on a retrospective data analysis of 162 women who underwent an early medical abortion in Southampton U.K. Relevant data on completeness of abortion and other details were analyzed. Results Majority of the women （67%） aged 20-30 years old, 22% were between 30 and 40 years old and 1% were above 40 years old when they came for abortion. About 94.5% women had complete abortion following the use of single dose mifepristone combined with two doses of misoprostol, 4.9% had an incomplete abortion and 0.6% had failure of the procedure. These figures had significantly improved over the results of similar audit in 2005 with single dose of misoprostol to women below 7 weeks of pregnancy. The results in this audit were 82.1% complete abortion, 7.2% incomplete abortion and O. 7% failed procedure. Conclusion Mifepristone in combination with two doses of misoprostol appears to be more effective in all cases of early medical abortion when compared with single dose of misoprostol for termination below 49 d （7 weeks） and two doses of misoprostol between 49 d and 63 d （7-9 weeks） of pregnancy.

甜瓜AMS基因结构分析及基因编辑载体构建

【目的】研究鉴定甜瓜雄性不育候选基因ABORTED MICROSPORES(AMS)的基因家族,分析CRISPR基因编技术并构建其敲除载体,为甜瓜雄性不育基因AMS功能验证提供依据。【方法】采用生物信息学技术鉴定甜瓜雄性不育候选基因ABORTED MICROSPORES(AMS)家族基因,分析其进化关系、保守基序及理化性质。利用CRISPR/Cas9基因编辑技术以甜瓜AMS基因外显子区设计gRNA引物,以载体pHSN401为模板,扩增获得sgRNA克隆框,使用Bsa I酶切pHSN401载体,利用DNA重组酶构建重组载体并转化农杆菌,挑选单克隆进行培养,随后进行菌液PCR鉴定。【结果】甜瓜AMS基因编码的蛋白质长度从501~605 aa不等,平均分子量约为59351 Da,等电点为5.04~6.45,甜瓜大部分AMS基因定位在细胞核;利用CRISPR/Cas9基因编辑技术,在AMS基因的CDS区设计3个靶位点,分别是AMS-pHSN401-1、AMS-pHSN401-2和AMS-pHSN401-3。【结论】AMS基因主要被预测在细胞核中表达,利用CRISPR/Cas9基因编辑技术构建甜瓜敲除重组载体AMS-pHSN401并转化农杆菌,获得阳性克隆。

Morphological, physiological and molecular characteristics of the seedless 'Hongjiangcheng' sweet orange

Seedless citrus has become one of the breeding goals due to its high edible ratio and convenience in fresh consumption and processing.In this study, the ‘Hongjiangcheng' sweet orange(WT) and its seedless mutant(MT) after cobalt-60 radiation were selected to study the formation metabolism of citrus seedless phenotype. Compared with WT, the MT had altered primary metabolite contents, as indicated by GC-MS analysis. The mature pollen of the MT was mostly distorted and shrunken, and the orange mutant exhibited significantly lower fertility than the WT. Through pollination experiments and paraffin sectioning of the MT, we observed self-compatibility during pollen tube germination in situ, in combination with the absence of natural parthenocarpy and arrested zygotic embryo development at the fourth week after pollination. From transcriptomic analyses of ovules in the fourth week, 815 differentially expressed genes(DEGs) were identified.Furthermore, according to the annotation of gene function and qRT-PCR analysis, Cs4g10930, Cs5g21900 and orange1.1t02243 were identified as candidate genes that may govern the mechanism of seedlessness. Finally, Agrobacterium-mediated transformation verified that the overexpression of Cs4g10930 and Cs5g21900 in Newhall navel orange calli inhibited embryoid production. This study provides a better understanding of seedless formation in citrus and two key genes that may play an important role in the early selection of seedless lines in citrus breeding programs.