Effect of Histamine H2 Receptor Antagonists on All-Cause Mortality in Critically Ill Patients With Essential Hypertension: A Retrospective Cohort Study

Previous studies found that histamine H2 receptor antagonists (H2RAs) had blood pressure lowering and cardioprotective effects, but the impact of H2RAs on the survival outcomes of critically ill patients with essential hypertension is still unclear. The aim of this study was to investigate the association of H2RAs exposure with all-cause mortality in patients with essential hypertension based on Medical Information Mart for Intensive Care III database. A total of 17,739 patients were included, involving 8482 H2RAs users and 9257 non-H2RAs users. Propensity score matching (PSM) was performed to improve balance between 2 groups that were exposed to H2RAs or not. Kaplan-Meier survival curves were used to compare the cumulative survival rates and multivariable Cox regression models were performed to evaluate the association between H2RAs exposure and all-cause mortality. After 1:1 PSM, 4416 pairs of patients were enrolled. The results revealed potentially significant association between H2RAs exposure and decreased 30-day, 90-day, and 1-year mortalities in multivariate analyses (HR = 0.783, 95% CI: 0.696-0.882 for 30-day; HR = 0.860, 95% CI: 0.778-0.950 for 90-day; and HR = 0.883, 95% CI: 0.811-0.961 for 1-year mortality, respectively). Covariate effect analyses showed that the use of H2RAs was more beneficial in essential hypertension patients with age ≥ 60, BMI ≥ 25 kg/m2, coronary arteriosclerosis, stroke, and acute kidney failure, respectively. In conclusion, H2RAs exposure was related to lower mortalities in critically ill patients with essential hypertension, which provided novel potential strategy for the use of H2RAs in essential hypertension patients.

The benefit of omeprazole exposure on all-cause mortality and length of ICU/hospital stay might vary with age in critically ill pediatric patients: A cohort study

PURPOSE

To investigate the association between proton pump inhibitors (PPIs) administration during hospitalization and mortality and length of stay in critically ill pediatric patients.

MATERIALS AND METHODS

This is a retrospective observational cohort study on pediatric ICU patients (0 to 18 years). Propensity score matching (PSM), Kaplan-Meier curves, Cox proportional hazards model and Linear regression model was applied for assessing the effects of PPIs on mortality and other outcomes during hospitalization.

RESULTS

A total of 2269 pediatric ICU patients were included, involving 1378 omeprazole (OME) users and 891 non-OME users. The results showed significant association between OME exposure and decreased ICU stay (β -0.042; 95% CI -0.073--0.011; P = 0.008) but prolonged non-ICU hospital stay (β 0.121; 95% CI 0.097-0.155; P = 0.040). No statistical significance was observed between OME exposure and reduced mortality, but the OME group had a slightly decreased tendency in 28-day mortality (HR 0.701; 95% CI 0.418-1.176) and in-hospital mortality (HR 0.726; 95% CI 0.419-1.257). Furthermore, subgroup analyses revealed that the decreased tendency of mortality were more obvious in patients less than 1 year old compared with older pediatric patients, although not statistically significant. In addition, we also observed that OME exposure was significantly associated with reduced mortality of general ICU subgroup.

CONCLUSIONS

This study provided a sign that PPIs used only in the ICU, rather than throughout hospital stay, might provide more benefit for critically ill pediatric patients. Additionally, younger pediatric patients might gain relatively more benefit than older children when receiving PPIs.

Histamine H2 receptor antagonist exhibited comparable all-cause mortality-decreasing effect as β-blockers in critically ill patients with heart failure: a cohort study

Background: Our previous study reported that histamine H2 receptor antagonists (H2RAs) exposure was associated with decreased mortality in critically ill patients with heart failure (HF) through the same pharmacological mechanism as β-blockers. However, population-based clinical study directly comparing the efficacy of H2RAs and β-blockers on mortality of HF patients are still lacking. This study aims to compare the association difference of H2RAs and β-blockers on mortality in critically ill patients with HF using the Medical Information Mart for Intensive Care III database (MIMIC-III). Methods: Study population was divided into 4 groups: β-blockers + H2RAs group, β-blockers group, H2RAs group, and Non-β-blockers + Non-H2RAs group. Kaplan-Meier curves and multivariable Cox regression models were employed to evaluate the differences of all-cause mortalities among the 4 groups. Propensity score matching (PSM) was used to increase comparability of four groups. Results: A total of 5593 patients were included. After PSM, multivariate analyses showed that patients in H2RAs group had close all-cause mortality with patients in β-blockers group. Furthermore, 30-day, 1-year, 5-year and 10-year all-mortality of patients in β-blockers + H2RAs group were significantly lower than those of patients in β-blockers group, respectively (HR: 0.64, 95%CI: 0.50-0.82 for 30-day; HR: 0.80, 95%CI: 0.69-0.93 for 1-year mortality; HR: 0.83, 95%CI: 0.74-0.93 for 5-year mortality; and HR: 0.85, 95%CI: 0.76-0.94 for 10-year mortality, respectively). Conclusion: H2RAs exposure exhibited comparable all-cause mortality-decreasing effect as β-blockers; and, furthermore, H2RAs and β-blockers had additive or synergistic interactions to improve survival in critically ill patients with HF.

A meta-analysis of associations of IL-10 gene polymorphisms with acute leukemia susceptibility

BACKGROUND

Recently, increasing evidence has demonstrated that IL-10 single nucleotide polymorphisms (SNPs) are associated with the risk of acute leukemia (AL), but the findings of different articles remain controversial. Thus, we performed a meta-analysis to further investigate the exact roles of IL-10 SNPs in AL susceptibility.

METHODS

Six common Chinese and English databases were utilized to retrieve eligible studies. The strength of the association was assessed by calculating odds ratios and 95 % confidence intervals. All analyses were carried out using Review Manager (version 5.3) and STATA (version 15.1). The registered number of this research is CRD42022373362.

RESULTS

A total of 6391 participants were enrolled in this research. The results showed that the AG genotype of rs1800896 increased AL risk in the heterozygous codominant model (AG vs. AA, OR = 1.41, 95 % CI = 1.04-1.92, P = 0.03) and overdominant model (AG vs. AA + GG, OR = 1.32, 95 % CI = 1.04-1.70, P = 0.03). In the subgroup analysis, associations between the G allele, GG genotype, AG genotype, AG + GG genotype of rs1800896 and increased AL risk were also observed in the mixed population based on allelic, homozygote codominant, heterozygous codominant, dominant, and overdominant models. Furthermore, an association between the AC genotype of rs1800872 and increased AL risk was observed in the Caucasian population in the overdominant model. However, the rs1800871, rs3024489 and rs3024493 polymorphisms did not affect AL risk.

CONCLUSION

IL-10 rs1800896 and rs1800872 affected the susceptibility of AL and therefore may be biomarkers for early screening and risk prediction of AL.

Comparative efficacy and safety of uricosuric agents in the treatment of gout or hyperuricemia: a systematic review and network meta-analysis

OBJECTIVES

The current world witnesses a greatly increased prevalence and incidence of hyperuricemia and gout with unfortunately the comparative efficacy and safety of present available uricosuric agents remaining uncertain. We herein aimed to investigate the most appropriate uricosuric agent for gout or hyperuricemia patients.

METHOD

PubMed, Embase, Cochrane Library databases, and ClinicalTrials.gov from inception to 2 July 2022 were searched to retrieve eligible studies assessing efficacy and safety of uricosuric drugs in hyperuricemia or gout patients. Network meta-analysis was carried out using the Stata 16.0 software.

RESULTS

Twelve randomized controlled trials comprising 1851 patients were eventually included. Network meta-analysis showed that dotinurad 4 mg once daily, verinurad, dotinurad 2 mg once daily, dotinurad 1 mg once daily, and benzbromarone were the top 5 effective treatments to achieve target serum uric acid. Furthermore, dotinurad 4 mg once daily was more effective at achieving urate-lowering targets (RR of dotinurad 4 mg once daily vs. probenecid: 1.68, 95% CI [1.13; 2.50]) and safer (RR of probenecid vs. dotinurad 4 mg once daily: 1.77, 95% CI [0.69; 4.56]) than probenecid.

CONCLUSIONS

This network meta-analysis demonstrated an important absolute benefit of dotinurad 4 mg once daily to achieve target serum uric acid and low risk of adverse events for drug treatment of gout or hyperuricemia patients. Additionally, verinurad might be used as an alternative uricosuric therapeutic option to dotinurad. These findings provided further comprehensive insight into the treatment value of current uricosuric agents for gout or hyperuricemia. Key Points 1. This is the first systematic review and network meta-analysis examining the efficacy and safety of currently available uricosuric agents in gout or hyperuricemia patients. 2. Recommended doses of dotinurad 4mg once daily used for the treatment of gout or hyperuricemia patients can significantly decrease serum uric acid levels. 3. The present findings will provide further comprehensive insight into the treatment value of certain uricosuric agents for gout or hyperuricemia.

Phospho-proteomics identifies a critical role of ATF2 in pseudorabies virus replication

Pseudorabies virus (PRV), an etiological agent of pseudorabies in livestock, has negatively affected the porcine industry all over the world. Epithelial cells are reported as the first site of PRV infection. However, the role of host proteins and its related signaling pathways in PRV replication is largely unclear. In this study, we performed a quantitative phosphoproteomics screening on PRV-infected porcine kidney (PK-15) epithelial cells. Totally 5723 phosphopeptides, corresponding to 2180 proteins, were obtained, and the phosphorylated states of 810 proteins were significantly different in PRV-infected cells compared with mock-infected cells (P ​< ​0.05). GO and KEGG analysis revealed that these differentially expressed phosphorylated proteins were predominantly related to RNA transport and MAPK signaling pathways. Further functional studies of NF-κB, transcription activator factor-2 (ATF2), MAX and SOS genes in MAPK signaling pathway were analyzed using RNA interference (RNAi) knockdown. It showed that only ATF2-knockdown reduces both PRV titer and viral genome copy number. JNK pathway inhibition and CRISPR/Cas9 gene knockout showed that ATF2 was required for the effective replication of PRV, especially during the biogenesis of viral genome DNA. Subsequently, by overexpression of the ATF2 gene and point mutation of the amino acid positions 69/71 of ATF2, it was further demonstrated that the phosphorylation of ATF2 promoted PRV replication. These findings suggest that ATF2 may provide potential therapeutic target for inhibiting PRV infection.

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Phosphoproteomic profiling of PRV-infected PK-15 ​cells with iTRAQ-quantification.

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JNK pathway regulates ATF2 phosphorylation and PRV replication.

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Phosphorylation of ATF2 promotes PRV replication.

Deciphering the Biosynthetic Mechanism of Pelletierine in Lycopodium Alkaloid Biosynthesis

Pelletierine, a proposed building block of Lycopodium alkaloids (LAs), was demonstrated to be synthesized via the non-enzymatic Mannich-like condensation of Δ¹-piperideine and 3-oxoglutaric acid produced by two new type III PKSs (HsPKS4 and PcPKS1) characterized from Huperzia serrata and Phlegmariurus cryptomerianus, respectively. The findings provide new insights for further understanding the biosynthesis of LAs such as huperzine A.

Highly Efficient Base Editing in Viral Genome Based on Bacterial Artificial Chromosome Using a Cas9-Cytidine Deaminase Fused Protein

Viruses evolve rapidly and continuously threaten animal health and economy, posing a great demand for rapid and efficient genome editing technologies to study virulence mechanism and develop effective vaccine. We present a highly efficient viral genome manipulation method using CRISPR-guided cytidine deaminase. We cloned pseudorabies virus genome into bacterial artificial chromosome, and used CRISPR-guided cytidine deaminase to directly convert cytidine (C) to uridine (U) to induce premature stop mutagenesis in viral genes. The editing efficiencies were 100%. Comprehensive bioinformatic analysis revealed that a large number of editable sites exist in pseudorabies virus (PRV) genomes. Notably, in our study viral genome exists as a plasmid in E. coli, suggesting that this method is virus species-independent. This application of base-editing provided an alternative approach to generate mutant virus and might accelerate study on virulence and vaccine development.

[Multiple-factor analysis of serum allergen distribution of patients with allergic rhinitis and level of main allergen IgE in Shenyang area]

Objective:To discuss multiple-factor analysis of serum allergen distribution of patients with allergic rhinitis and level of main allergen IgE in Shenyang area, and to provide a scientific basis for the prevention of allergic rhinitis in this area.Method:Serum IgE was detected in 749 cases［501 cases of male (66.8%), and 248 cases of female (33.2%)］, with allergic rhinitis.The age range was from 3 to 65 years old, and they were divided into 5 groups based on age. A questionnaire survey was conducted to analyze the distribution of serum allergens and to carry out a multiple-factor analysis of level of the main allergen IgE in patients.Result:The primary allergen was house dust mite/dust mite in each age group, and the differences in the positive rate of elm, mold, cat/dog fur scurf, cockroach and ragweed among different groups were statistically significant（P<0.01 or P<0.05）.The ingested allergen sequencing for all age groups: the distribution of 7-14 years old group and 15-35 years old group were consistent with that of the whole, among the under 6 years old group, mango and pineapple was ranked 1st,beef and mutton was ranked 2nd,the occurrence rate of shrimp and crab rose to the 3rd place, among the 36-60 years old group, mango, pineapple and milk was ranked 1st, egg was ranked 2nd, and beef and mutton ranked 3rd, the differences in positive rate of mango and pineapple, beef and mutton, crab and nut among all groups were statistically significant(P<0.01 or P<0.05).The IgE level of cockroach was impacted by the allergic history, home cultivation of flowers and plants and animal domestication. The IgE level of mold was impacted by sex, allergy history, home rearing of pet and furniture updates. The IgE level of wormwood was impacted by allergy history and asthma history. The IgE level of peanut was impacted by age and allergy history. The IgE level of egg was impacted by history of food and drink allergy, home cultivation of flowers and plants and home rearing of pet. The IgE level of crab was impacted by the allergy history and home rearing of pet.Conclusion: The primary inhaled allergen in all groups is house dust mite/dust mite, and the ingested allergen varies in each group, which has provided a reference basis for prevention of ingested allergy.The varying influence factors for IgE level of primary allergens could be used to prevent the patients from contacting the allergen,and each risk factor has become a focus of prevention and control for patients, offering a major help to the prevention and treatment of allergic rhinitis.

Highly efficient base editing in bacteria using a Cas9-cytidine deaminase fusion

The ability to precisely edit individual bases of bacterial genomes would accelerate the investigation of the function of genes. Here we utilized a nickase Cas9-cytidine deaminase fusion protein to direct the conversion of cytosine to thymine within prokaryotic cells, resulting in high mutagenesis frequencies in Escherichia coli and Brucella melitensis. Our study suggests that CRISPR/Cas9-guided base-editing is a viable alternative approach to generate mutant bacterial strains.

Ke Zheng and colleagues repurposed a nickase Cas9-cytidine deaminase fusion protein to effectively direct the conversion of cytosine to thymine on bacterial genome. This study suggests that CRISPR/Cas9-guided base-editing can be used to generate viable mutant bacterial strains.

[A clinical analysis of children with invasive pulmonary fungal infections after biliary atresia surgery]

OBJECTIVE

To investigate the clinical features of invasive pulmonary fungal infections (IPFIs) after biliary atresia (BA) surgery and related risk factors.

METHODS

A retrospective analysis was performed for the clinical data of 49 children with IPFIs after BA surgery, including clinical features, lung imaging findings, and pathogenic features. The risk factors for IPFIs after BA surgery were also analyzed.

RESULTS

The most common pathogens of IPFIs after BA surgery was Candida albicans (17 strains, 45%), followed by Candida tropicalis (7 strains, 18%), Aspergillus (6 strains, 16%), Candida krusei (3 strains, 8%), Candida glabrata (3 strains, 8%), and Candida parapsilosis (2 strains, 5%). Major clinical manifestations included pyrexia, cough, and shortness of breath, as well as dyspnea in severe cases; the incidence rate of shortness of breath reached 78%, and 35% of all children had no obvious rale. The multivariate logistic regression analysis showed that age at the time of surgery, time of glucocorticoid application, cumulative time of the application of broad-spectrum antibiotics, and recurrent cholangitis were major risk factors for IPFIs after BA surgery.

CONCLUSIONS

The three most common pathogens of IPFIs after BA surgery are Candida albicans, Candida tropicalis, and Aspergillus. It is important to perform surgery as early as possible, avoid recurrent cholangitis, and shorten the course of the treatment with broad-spectrum antibiotics and glucocorticoids for decreasing the risk of IPFIs.

[A clinical analysis of children with invasive pulmonary fungal infections after biliary atresia surgery]

OBJECTIVE

To investigate the clinical features of invasive pulmonary fungal infections (IPFIs) after biliary atresia (BA) surgery and related risk factors.

METHODS

A retrospective analysis was performed for the clinical data of 49 children with IPFIs after BA surgery, including clinical features, lung imaging findings, and pathogenic features. The risk factors for IPFIs after BA surgery were also analyzed.

RESULTS

The most common pathogens of IPFIs after BA surgery was Candida albicans (17 strains, 45%), followed by Candida tropicalis (7 strains, 18%), Aspergillus (6 strains, 16%), Candida krusei (3 strains, 8%), Candida glabrata (3 strains, 8%), and Candida parapsilosis (2 strains, 5%). Major clinical manifestations included pyrexia, cough, and shortness of breath, as well as dyspnea in severe cases; the incidence rate of shortness of breath reached 78%, and 35% of all children had no obvious rale. The multivariate logistic regression analysis showed that age at the time of surgery, time of glucocorticoid application, cumulative time of the application of broad-spectrum antibiotics, and recurrent cholangitis were major risk factors for IPFIs after BA surgery.

CONCLUSIONS

The three most common pathogens of IPFIs after BA surgery are Candida albicans, Candida tropicalis, and Aspergillus. It is important to perform surgery as early as possible, avoid recurrent cholangitis, and shorten the course of the treatment with broad-spectrum antibiotics and glucocorticoids for decreasing the risk of IPFIs.

Numerous mitochondrial DNA haplotypes reveal multiple independent polyploidy origins of hexaploids in Carassius species complex

Evolutionary trajectory and occurrence history of polyploidy have been extensively studied in plants, but they remain quite elusive in vertebrates. Here, we sampled and gathered 4,159 specimens of polyploid Carassius species complex including 1,336 tetraploids and 2,823 hexaploids from a large geographic scale (49 localities) across East Asia, and identified a huge number of 427 diverse haplotypes of mitochondrial control region, in which 74 haplotypes with total occurrence frequency up to 75.498% were shared by hexaploids and tetraploids. Significantly, these diverse haplotypes were clustered into four major lineages, and many haplotypes of hexaploids and tetraploids were intermixed in every lineage. Moreover, the evolutionary trajectory and occurrence history of four different lineages were revealed by a simplified time-calibrated phylogenetic tree, and their geographic distribution frequencies and haplotype diversity were also analyzed. Furthermore, lineage C and D were revealed to undergo population expansion throughout mainland China. Therefore, our current data indicate that hexaploids should undergo multiple independent polyploidy origins from sympatric tetraploids in the polyploid Carassius species complex across East Asia.

Wider geographic distribution and higher diversity of hexaploids than tetraploids in Carassius species complex reveal recurrent polyploidy effects on adaptive evolution

Polyploidy roles on adaptive evolution and ecological novelty have been extensively studied in plants but remained unclear in vertebrates owing to the rare polyploidy incidences. Here, a huge number of 3105 specimens in Carassius species complex including 2211 hexaploids and 894 tetraploids were sampled from 34 locations through mainland China. And hexaploids had wider geographic distribution than tetraploids especially in the areas with high altitude, high latitude and low annual precipitation. Then, an approximate 1050 bp transferrin (tf) fragments were amplified from all the samples, and 526 tf alleles were identified from a total of 37260 sequences at last. Intriguingly, higher nucleotide diversity of tf alleles in hexaploids than in tetraploids was revealed. Moreover, via phylogenetic analysis of tf alleles, potential origin center of Carassius species complex was deduced to be Yangtze River basin and hexaploids should undergo multiple independent polyploidy origins from sympatric tetraploids. These findings indicate that the hexaploids might possess stronger environmental adaptation and ecological novelty than the tetraploids, which provide an association paradigm of recurrent polyploidy and ecological context in polyploid vertebrates.

Molecular cloning and expression analysis of Fem1b from oriental river prawn Macrobrachium nipponense

Feminization-1 homolog b (Fem1b) is one of the genes essential for male development and play central roles in sex determination of Caenorhabditis elegans. In this study, we cloned and characterized the full-length Fem1b cDNA from the freshwater prawn Macrobrachium nipponense (MnFem1b) in different tissues and at different developmental stages. Real-time quantitative reverse polymerase chain reaction (RT-qPCR) showed that the MnFem1b gene was expressed in all investigated tissues, with the highest expression level found in the testes. The results revealed that the MnFem1b gene might play roles in aspects of development of the male prawn phenotype. The RT-qPCR also revealed that MnFem1b mRNA expression was significantly increased at 10 days after metamorphosis. The expression levels in all investigated tissues showed a certain degree of sexually dimorphism, the expression levels in males were significantly higher than those in females (P < 0.05). Notably, the highest expression of MnFem1b was found in the testes. The expression of MnFem1b in different tissues indicates that it plays multiple biological functions in M. nipponense.

[Kuntai capsule combined with gonadotropin releasing hormone agonist in treatment of moderate-severe endometriosis: a clinical observation]

OBJECTIVE

To observe the effect of Kuntai Capsule (KC), a Chinese patent medicine, in add-back therapy for gonadotropin-releasing hormone agonist (GnRH-a) treatment for moderate-severe endometriosis (EM).

METHODS

Totally 100 patients suffering from stage III/IV EM, who were confirmed by laparoscopic surgery were randomly assigned to the GnRH-a group (A) and the KC combined GnRH-a group (B), 50 in each group. Patients in Group A were hypodermically injected with goserelin (3.6 mg), once per 4 weeks. Those in Group B additionally took KC, 4 pills each time, three times per day. The therapeutic course for all was 12 weeks. Serum levels of estradiol (E2), follicle stimulating hormone (FSH), bone gamma-carboxyglutamic-acid-containing proteins (BGP) were measured respectively. Kupperman Menopausal Index (KMI) and bone mineral density (BMD) of the lumbar vertebra were also compared between the two groups.

RESULTS

Serum levels of E2 and FSH both significantly decreased in the two groups at week 12 of the treatment (P < 0.05), when compared with pre-treatment. Compared with before treatment in the same group, KMI increased in the two groups (P < 0.05). Compared with before treatment in the same group, BMI decreased in the two groups with no statistical difference (P > 0.05). Serum BGP increased after 12-week treatment (P < 0.05). Compared with Group A after treatment, serum levels of E2 and FSH both significantly increased in Group B (P < 0.05). There was no statistical difference in KMI between the two groups (P > 0.05). As for the incidence of menopausal symptoms, better effects in improving symptoms such as hot flashes, sleep disorders, and vaginal dryness were obtained in Group B than in Group A (P < 0.05). There was no significant difference in the post-pre-treatment difference of BMI between the two groups, but with statistical post-pre-treatment difference in the BGP level (P < 0.05).

CONCLUSIONS

HKC combined GnRH-a could effectively reduce GnRH-a treatment induced partial low estrogen symptoms, improve increased serum BGP levels after GnRH-a therapy.

High male incidence and evolutionary implications of triploid form in northeast Asia Carassius auratus complex

Carassius auratus complex is believed to originate from East Eurasia and consist of diploid and triploid forms. Diploid form reproduces sexually, whereas triploid form possesses mixture modes of unisexual gynogenesis and sexual reproduction, which makes it a unique case to study evolutionary issues among vertebrates. In this study, we identified 337 triploid individuals from 386 specimens of Carassius auratus complex sampled from 4 different sites of Xingkai Lake and Suifen River on the northeast Asia transboundary areas of Russia and China, and found that triploids were ubiquitous, whereas diploids existed only in SII site of Suifen River. Triploid males were detected in all surveyed sites, and an unusually high triploid male incidence (23%) was found in the Chinese reach of Suifen River. Then, nuclear and cytoplasmic markers were used to analyze their genetic diversity and phylogenetic relationship. A total of 61 distinct tf alleles and 35 mtDNA CR haplotypes were revealed. Higher genetic diversity and divergence were confirmed in triploids than in diploids, and identical genetic background between triploid males and females was demonstrated. Moreover, evolutionary implications and roles of triploid males were suggested in population proliferation and diversity creation of the triploid form.

A novel nucleo-cytoplasmic hybrid clone formed via androgenesis in polyploid gibel carp

BACKGROUND

Unisexual vertebrates have been demonstrated to reproduce by gynogenesis, hybridogenesis, parthenogenesis, or kleptogenesis, however, it is uncertain how the reproduction mode contributes to the clonal diversity. Recently, polyploid gibel carp has been revealed to possess coexisting dual modes of unisexual gynogenesis and sexual reproduction and to have numerous various clones. Using sexual reproduction mating between clone D female and clone A male and subsequent 7 generation multiplying of unisexual gynogenesis, we have created a novel clone strain with more than several hundred millions of individuals. Here, we attempt to identify genetic background of the novel clone and to explore the significant implication for clonal diversity contribution.

METHODS

Several nuclear genome markers and one cytoplasmic marker, the mitochondrial genome sequence, were used to identify the genetic organization of the randomly sampled individuals from different generations of the novel clone.

RESULTS

Chromosome number, Cot-1 repetitive DNA banded karyotype, microsatellite patterns, AFLP profiles and transferrin alleles uniformly indicated that nuclear genome of the novel clone is identical to that of clone A, and significantly different from that of clone D. However, the cytoplasmic marker, its complete mtDNA genome sequence, is same to that of clone D, and different from that of clone A.

CONCLUSIONS

The present data indicate that the novel clone is a nucleo-cytoplasmic hybrid between the known clones A and D, because it originates from the offspring of gonochoristic sexual reproduction mating between clone D female and clone A male, and contains an entire nuclear genome from the paternal clone A and a mtDNA genome (cytoplasm) from the maternal clone D. It is suggested to arise via androgenesis by a mechanism of ploidy doubling of clone A sperm in clone D ooplasm through inhibiting the first mitotic division. Significantly, the selected nucleo-cytoplasmic hybrid female still maintains its gynogenetic ability. Based on the present and previous findings, we discuss the association of rapid genetic changes and high genetic diversity with various ploidy levels and multiple reproduction modes in several unisexual and sexual complexes of vertebrates and even other invertebrates.