Preparation and analysis of spermatocyte meiotic pachytene bivalents of pigs for gene mapping

Well-spread meiotic pachytene bivalents were obtained by using the prolonged hypotonic treatment com-bined with high chloroform Carnory’s fixative solution from cells of the testes of domestic pigs. Comparison in the division index and length of pachytene bivalents with metaphase chromosomes showed that those of the former are 5 times higher and 3.42(1.87-5.98) times longer than those of the latter. Comparative studies on chromomere maps of bivalents and mitotic chromosomal G-bands were conducted by using the chromo-some 12 as a example. Sex vesicle and various shapes of synaptic sex chromosomes have been observed.Two-color PRimed IN Situ (PRINS) labeling has been conducted successfully on pachytene bivalents of pigs.

The Iampbrush-like chromosome" on pachytene bivalents of rice-field eels (Monopterus albus Zuiew)

IN our previous studies, we have used in situ nick translation techniques for analysis of DNaseⅠ sensitivity and restriction enzymes in situ cleavage on pachytene bivalents of rice-field eels(Monopterus albus Zuiew). A characteristic construction of bivalents--"the lampbrush-likechromosome", which has not been reported yet, was detected in some pachytene bivalents.

An idiogram on pachytene bivalents with high resolution multiple bands of zebrafish(Danio rerio)

Well spread pachytene bivalents with high-resolution multiple bands of zebrafish were obtained after the testes were treated with alkaline hypotonic solution and high chloroform fixative solution. This might be the pattern with the largest number of multiple bands obtained from fish chromosomes so far published. Both the number and character of the bands in each bivalent were stable. According to the principles of ISCN (1978) and ISCN (1981), an idiogram of 599 bands was set up, and the detailed description of the landmark system and the band positions were given.

High Resolution G-banding and Idiogram on Pachytene Bivalents of Rice Field Eels(Monopterus albus Zuiew)

Well spread pachytene bivalents and high resolution G-handing patterns have been obtainedby using the prolonged hypotonic treatment combined with the trypsin-hot salt banding technique in the sper-maries of rice field eels(Monopterus albus Zuiew).Each bivalent has been idendified and a total of 310—450 bands on 12 bivalents observed.This might bethe largest number of multiple bands obtained from fish chromosomes so far published.An idiogram of 372G-bands has been set up and detailed descriptions of the landmark systems and the band positions have beengiven.

Immuno-Protective Efficiency of the Bivalent Inactivated Vaccine Against Vibrio scophthalmi and Aeromonas salmonicida Infections in Turbot(Scophthalmus maximus L.)

Vibrio scophthalmi and Aeromonas salmonicida can cause high turbot mortality and huge economic losses.Presently,vaccination is the most promising method for preventing communicable diseases.In this study,we used formalin to kill V.scophthalmi and A.salmonicida cells,and mixed with the mineralized oil adjuvant(Montanide^(TM)ISA 763 AVG)to prepare the bivalent inactivated vaccine.The results showed that turbot inoculated with the bivalent inactivated vaccine exhibited strong tolerance to the infection of V.scophthalmi and A.salmonicida,and no obvious clinical symptoms and pathological changes were observed.The activities of enzymes lysozyme,acid phosphatase and complement C3 had significantly increased after the vaccination.The antibody titer response of vaccinated turbot was greatly boosted,which was positively connected with the immunological impact according to ELISA results.Simultaneously,the expression levels of immune-related genes such as MHC-IIα,MHC-IIβ,CD4,CD8,TNF-αand IL^(-1)βwere up-regulated,demonstrating that it might stimulate humoral and cellular immunological response in turbot.These findings highlight the potential of the bivalent inactivated vaccine for controlling V.scophthalmi and A.salmonicida infections in turbot.

Study of the Temperature-Programmed Desorption of Carbon Dioxide (CO2) on Zeolites X Modified with Bivalent Cations

Study of physisorbed and chemisorbed carbon dioxide (CO2) species was carried out on the NaX zeolite modified by cationic exchanges with bivalent cations (Ca2+ and Ba2+) by temperature-programmed desorption of CO2 (CO2-TPD). Others results were obtained by infrared to complete the study. The results of this research showed, in the physisorption region (213 - 473 K), that the cationic exchanges on NaX zeolite with bivalent cations increase slightly the interactions of CO2 molecule with adsorbents and/or cationic site. Indeed, the desorption energies of physisorbed CO2 obtained on the reference zeolite NaX (13.5 kJ·mol-1) are lower than that of exchanged zeolites E-CaX and E-BaX (15.77 and 15.17 kJ·mol-1 respectively). In the chemisorbed CO2 region (573 - 873 K), the desorption energies related to desorbed species (bidentate carbonates: CO32-) on the exchanged zeolites E-CaX and E-BaX are about 81 kJ·mol-1, higher than the desorbed species (bicarbonates: HCO32-) on the reference R-NaX (62 kJ·mol-1). In addition, the exchanged E-BaX zeolite develops the secondary adsorption sites corresponding to bicarbonates species with desorption energies of 35 kJ·mol-1 lower to desorption energies of bicarbonates noted on the reference zeolite NaX.

Preferential Bivalent Formation in Tetraploid Male of Pacific Oyster Crassostrea gigas Thunberg

Artificially induced tetraploid Pacific oyster, Crassostrea gigas Thunberg, produces more aneuploid gametes than nor- mal diploid one, although they showed a comparable fecundity to diploidy. The meiotic chromosome configuration of 3 tetraploid and 1 tetraploid/triploid mosaic males were analyzed through direct chromosome observation. A majority of metaphase I spermato- cytes contained both bivalents and quadrivalents. The chromosome configuration of these males was characterized by preferential formation of bivalents to quadrivalents. Bivalents appeared in all spermatocytes and consisted of 86% of all chromosome aggregates. In comparison, quadrivalents occurred in 91% spermatocytes and consisted of only 12.6% of all chromosome aggregates. The mean bivalent frequency per spermatocyte varied between 14.4 and 17.2; while that of quadrivalents varied between 2.2 and 2.7. Most quadrivalents were tandemly chained （58%） or circled （39%）. The total number of chromosome aggregates per spermatocyte ranged from 13 to 20 with an average of 17.6; while 18 （16 bivalents and 2 quadrivalents） was the most frequent. Univalents and trivalents appeared in very low frequency. Aneuploid （hypotetraploid） spermatocytes were observed in a low frequency. The chromosome con- figuration of in the mosaic individual was similar to that of tetraploid individuals. The percentage of triploid spermatocytes （2%） of the mosaic individual was significantly lower （2＂2 =30, P〈 0.01） than that of triploid cells （46%） in its somatic tissue.

ROLE OF BIVALENT CATIONS AND CHOLINE IN ATP-INDUCED APOPTOSIS OF HUMAN LYMPHOCYTES WITH P2Z RECEPTORS

The role of bivalent cations and choline in ATP induced apoptosis via P2Z purinoceptor was investigated in human leukemic lymphocytes. In vitro exposure of leukemic lymphocytes with P2Z receptors to 1 mmol/L ATP or 0 1 mmol/L benzoylbenzoic ATP(BzATP) for 8 h in the presence of choline, 1 mmol/L Mg 2+ or other bivalent cations, and ATP induced DNA breaks, associated with apoptosis were quantified by TdT assay. We observed that (1) Extracellular Mg 2+ or Ca 2+ stimulated ATP induced DNA fragmentation in a dose dependent manner, and the compatible evidence was provided by the inhibition of ATP induced DNA fragmentation in the present of EGTA or EDTA; (2) ATP induced DNA fragmentation was completely inhibited by 1 mmol/L Zn 2+ ;(3)ATP induced DNA breaks were not affected by Ba 2+ , Sr 2+ , Co 2+ when they were substituted for extracellular Mg 2+ or Ca 2+ ;(4)Choline, an inhibitor of phospholipase D(PLD) stimulated by ATP through P2Z receptor in human lymphocytes, was also a partial inhibitor of ATP induced DNA fragmentation, and the results were confirmed by flow cytometric analysis (FCA); (5)ATP induced DNA fragmentation was completely obliterated when the temperature was lower than 10℃. These results suggest that the endonuclease and PLD may be involved in ATP induced apoptosis in human lymphocytes via P2Z receptor.

RADIOIODINATION AND PHARMACOKINETICS OF BIVALENT ANALOG OF PRACTOLOL AS MYOCARDIAL IMAGING AGENT

Solid phase exchange radioiodination method was used to label the compound.Pharmacokinetics was studied in rats and the data were dealt with by computer. The results indicate that the compound would be a potential myocardial imaging agent.

Molecular dynamics simulations of A-DNA in bivalent metal ions salt solution

A-form DNA is one of the biologically active double helical structure.The study of A-DNA structure has an extensive application for developing the field of DNA packaging in biotechnology.In aqueous solution,the A-DNA structure will have a free transformation,the A-DNA structure will be translated into B-form structure with the evolution of time,and eventually stabilized in the B-DNA structure.To explore the stability function of the bivalent metal ions on the A-DNA structure,a series of molecular dynamics simulations have been performed on the A-DNA of sequence(CCCGGCCGGG).The results show that bivalent metal ions(Mg^(2+),Zn^(2+),Ca^(2+))generate a great effect on the structural stability of A-DNA in the environment of high concentration.As the interaction between metal ions and electronegative DNA chains,the stability of A-DNA in solution is gradually improved with the increasing solution concentration of ions.In metal salt solution with high concentration,metal ions can be easily distributed in the solvation shells around the phosphate groups and further lead to the formation of shorter and more compact DNA structure.Also,under the condition of the same concentration and valency of the metal ions,the stability of A-DNA structure is different.The calculations indicate that the structure of A-DNA in CaCl_(2)solution is less stable than in MgCl_(2)and ZnCl_(2)solution.

Histone methylation in Huntington's disease:are bivalent promoters the critical targets?

Huntington’s disease（HD）is a currently incurable,late onset,progressive,ultimately fatal neurological disorder（Bates et al.,2015）.We have recently published the results of comprehensive genetic interaction tests aimed at identification of histone methyltransferases and demethylases involved in HD pathogenesis in a Drosophila model of the disease（Song et al.,2018）.

Protection by Recombinant Newcastle Disease Viruses (NDV) Expressing the Glycoprotein (G) of Avian Metapneumovirus (aMPV) Subtype A or B against Challenge with Virulent NDV and aMPV

Avian metapneumovirus (aMPV) and Newcastle disease virus (NDV) are threatening avian pathogens that can cause serious respiratory diseases in poultry worldwide. Vaccination, combined with strict biosecurity practices, has been the recommendation for controlling these diseases in the field. In the present study, we generated NDV LaSota vaccine strain-based recombinant viruses expressing the glycoprotein (G) of aMPV, subtype A or B, using reverse genetics technology. These recombinant viruses, rLS/aMPV-A G and rLS/aMPV-B G, were characterized in cell cultures and evaluated in turkeys as bivalent, next-generation vaccines. The results showed that these recombinant vaccine candi-dates were slightly attenuated in vivo, yet maintained similar growth dynamics, cytopathic effects, and virus titers in vitro when compared to the parental LaSota virus. The expression of the aMPV G protein in recombinant virus-infected cells was detected by immunofluorescence. Vaccination of turkeys with rLS/aMPV-A G or rLS/aMPV-B G conferred complete protection against velogenic NDV, CA02 strain challenge and partial protection against homologous patho-genic aMPV challenge. These results suggest that the LaSota recombinant virus is a safe and effective vaccine vector and expression of the G protein alone is not sufficient to provide full protection against aMPV-A or -B infections. Ex-pression of other aMPV-A or -B virus immunogenic protein(s) individually or in conjunction with the G protein may be necessary to induce stronger and more protective immunity against aMPV diseases.

THE STRUCTURE OF ACTIVE SITE AND THE ROLE OF BIVALENT CATION IN FERRITE-FERRIC OXIDE CATALYSTS FOR OXIDATIVE DEHYDROGENATION OF BUTENES

The relations between catalytic activities and compositions of the systems Mg_xZn_(1-x)Fe_2O_4, Co_xZn_(1-x)Fe_2O_4, Co_xMg_(1-x)Fe_2O_4, Cd_xZn_(1-x)Fe_2O_4 and Mg_xZn_(1-x)Fe_2O_4·0.17Fe_2O_3 have been studied by flow differential reactor, XRD, and derivative IR techniques. It has been found that the appropriate normal-inverse spinel combination substantially increases the activity for the title raction. The structure of the active site and the role of the bivalent cation in the title catalyst have been inferred.

Effectiveness of Hemorrhagic Fever with Renal Syndrome Bivalent Vaccine in China:A Metaanalysis

Objective To evaluate the effectiveness of Hemorrhagic Fever with Renal Syndrome(HFRS) bivalent vaccine in field.Methods The articles on effectiveness of HFRS bivalent vaccine were retrieved from Vip Database,China Journal Full-text Database,Wanfang database,China Hospital Knowledge Database,Chinese Biomedical Literature Database,MEDLINE and ProQuest.Two persons extracted data and evaluated the quality of data together for meta-analysis.Results Seven articles were included into the analysis,and two articles were random clinical trials,five were quasi-trials.Meta-analysis showed that the overall effectiveness of HFRS bivalent vaccine was 85%(95%confidence interval:53%-95%) within one year after vaccination,and the effectiveness in two-dose recipients and three-dose recipients was 87%(95%confidence interval:54%-96%) and 60%,respectively;it was 96%(95%confidence interval:78%-99%) within 2-5 years after vaccination,and the effectiveness in two-dose recipients and three-dose recipients was 95%(95%confidence interval:19%-100%) and 96%(95%confidence interval:70%-99%),respectively;it was 100%(only one article included) within 6-9.6 years after vaccination.The effectiveness in two-dose recipients was 88%(95%confidence interval:62%-96%) during 1-2.5 years after vaccination,and that in three-dose recipients was 94%(95%confidence interval:70%-99%) during 1-5 years after vaccination.Conclusions HFRS bivalent vaccine is effective in field,and there is no difference between two-dose recipients and three-dose recipients.We should do some further studies on the long-term effectiveness of HFRS bivalent vaccine and on the age of vaccine reception.

Observation on the Efficiency of the Mongolian Gerbil Kidney Tissue Culture Inactivated Bivalent Vaccine for Hemorrhagic Fever with Renal Syndrome

The Z 10 and Z 37 strains of hemorrhagic fever with renal syndrome (HFRS) virus and the Mongolian gerbil ( Merions unguiculatus ) kidney cells were used to prepare the inactivated bivalent vaccine. A phase Ⅱ clinical trial use of this vaccine was made in 750 Chinese volunteers. The results showed that the side reaction rate was 2.5% and the sero-conversion rate of neutralizing antibodies against Hantaan and Seoul viruses in the inoculated volunteers were 87.6% and 96.3% respectively.

Construction of a bivalent vaccine candidate against HAdV4/HAdV7 based on capsid-display strategy via Red-homologous recombination and counter-selection methodology

Human adenoviruses(HAdvs)are major respiratory pathogens.Specifically,human adenovirus type 4(HAdV4)and human adenovirus type 7(HAdV7)are known for causing fever and pneumonia,with docu-mented cases of fatalities among the population.In recent years,HAdV4/HAdv7 has been implicated in caus-ing substantial outbreaks,leading to increased morbidity in multiple countries.Most HAdV4 and HAdV7 infections have been reported in North America,Asia,Europe,Africa,South America,Oceania,and the Middle East.Most fatalities occurred in North America(the United States)and Asia(China and Singapore).Engineered recombinant adenoviruses have played a crucial role as vaccine vectors.In this study,we con-structed a recombinant adenovirus,Ad4ITRmut-Ad7E3,and evaluated it in vitro and in vivo.We observed that the replication rate of Ad4ITRmut-Ad7E3 was lower than that of the RI-67 strain,indicating that the mutation of inverted terminal repeats(ITRs)weakened the replication ability of HAdV4.Immunization of BALB/c mice with the bivalent Ad4ITRmut-Ad7E3 vaccine strain,administered by intraperitoneal injection and oral gavage,resulted in the elicitation of neutralizing antibodies targeting HAdV4 and HAdv7.This finding not only pro-vides a novel method and technique for the efficient construction of a polyvalent recombinant adenovirus vac-cine candidate against HAdV4 and HAdv7 but also against other prevalent adenovirus serotypes such as HAdV3,HAdV11,HAdV14,and HAdv55,from various regions.

Safety,immunogenicity,and preliminary efficacy of a randomized clinical trial ofomicron XBB.1.5-containing bivalent mRNA vaccine

Periodically updating coronavirus disease 19(COVID-19)vaccines that offer broad-spectrum protection is needed giventhe strong immune evasion by the circulating omicron sublineages.The effectiveness of prototype and BA.4/5-containing bivalent mRNA vaccines is reduced when XBB subvariants predominate.We initiated an observer-blinded,threearms study in 376 patients in Chinese individuals aged from 18 to 55 years old who had previously received three dosesCOVID-19 vaccine.Immunogenicity in terms of neutralizing antibodies elicited by a 30-mg dose of XBB.1.5-containingbivalent vaccine(RQ3027),a 30-mg dose of BA.2/BA.5-Alpha/Beta bivalent vaccine(RQ3025)and their precedent 30-mg Alpha/Beta(combined mutations)monovalent mRNA vaccine(RQ3013)and safety are primary and secondary endpoints,respectively.We recorded prescribed COVID-19 cases to explore the preliminary efficacy of three vaccines.RQ3027 and RQ3025 boosters elicited superior neutralizing antibodies(NAbs)against XBB.1.5,XBB.1.16,XBB.1.9.1,and JN.1 compared to RQ3013 at day 14 in participants without SARS-CoV-2 infection.All study vaccines were welltolerated without serious adverse reactions identified.The incidence rates per 1000 person-years of COVID-19 casesduring the 2nd-19th week after randomization were lowest in RQ3027.Overall,our data show that XBB.1.5-containingbivalent booster generated superior immunogenicity and better protection against newer severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)variants compared to BA.2/BA.5-containing bivalent and Alpha/Beta monovalentwith no new safety concerns.

Equitable bivalent booster allocation strategies against emerging SARS-CoV-2 variants in US cities with large Hispanic communities:The case of El Paso County,Texas

COVID-19 is a disease that disproportionately impacts the Hispanic population,due to the prevalence of certain risk factors and the high number of essential workers in this com-munity.In this work,we analyze the vaccination strategies that would minimize the COVID-19 health disparities in El Paso County,TX,in the context of the emergence of a new highly transmissible and immune-escaping SARS-CoV-2 variant.We stratify an age-structure stochastic SEIR model that tracks the evolution of immunity derived from in-fections and vaccination according to Hispanic vs non-Hispanic ethnicity and parameterize it to the demographic,health and immunization data of El Paso County,TX.After fitting the model,the results show that increasing vaccination with bivalent boosters by five-fold in anticipation of highly transmissible and immune escaping variants would decrease the cumulative hospital admissions and mortality from Mar 1,2023,to Dec 31,2023,by 62.72%and 61.41%,respectively.Further,our projections reveal that the disproportionate impact on the Hispanic community would be eliminated if approximately half of the doses that are given to the non-Hispanic group according to the equal distribution,would be re-allocated to the Hispanic population.Our findings can guide public health officials in US cities with large Hispanic communities and help them design vaccination strategies that minimize COVID-19 health disparities caused by emerging variants using specific vacci-nation strategies.

LincRNA1230 inhibits the differentiation of mouse ES cells towards neural progenitors

In vitro, mouse embryonic stem （ES） cells can differentiate into many somatic cell types, including neurons and glial cells. When cultured in serum-free medium, ES cells convert spontaneously and efficiently to a neural fate. Previous studies have shown that the neural conversion of mouse ES cells includes both the participation of neural-specific transcription factors and the regulation of epigenetic modifications. However, the intracellular mechanism underlying this intrinsic transition still re- mains to be further elucidated. Herein, we describe a long intergenic non-coding RNA, LincRNA1230, which participates in the regulation of the neural lineage specification of mouse ES cells. The ectopic forced expression of LincRNAI230 dramatically inhibited mouse ES cells from adopting a neural cell fate, while LincRNA1230 knockdown promoted the conversion of mouse ES cells towards neural progenitors. Mechanistic studies have shown that LincRNA1230 inhibits the activation of early neural genes, such as Pax6 and Soxl, through the modulation of bivalent modifications （tri-methylation of histone3 lysine4 and his- tone3 lysine27） at the promoters of these genes. The interaction of LincRNA1230 with Wdr5 blocked the localization of Wdr5 at the promoters of early neural genes, thereby inhibiting the enrichment of H3K4me3 modifications at these loci. Collectively, these findings revealed a crucial role for LincRNA1230 in the regulation of the neural differentiation of mouse ES cells.

Integration and inheritance stability of foreign Bt toxin gene in the bivalent insect-resistant transgenic cotton plants

Genetic and expressional stability of Bt toxin gene is crucial for the breeding of insect-resistant transgenic cotton varieties and their commercialization. Genomic Southern blot analysis of R3, R4 and R5 generations of bivalent transgenic insect-resistant cotton plants was done in order to determine the integration, the copy number and the inheritance stability of Bt toxin gene in the transgenic cotton plants. The results indicated that there was a 4.7 kb positive band in the Southern blot when the genomic DNA of the bivalent transgenic insect-resistant cotton plants and the positive control (the plasmid) were digested with HindⅢ respectively. This result proved that the Bt toxin gene had been integrated into the genome of the cotton in full length. There is only one XhoⅠ restriction site in the Bt toxin gene. Southern blot analysis indicated that many copies of Bt toxin gene had been integrated into the genome of the cotton when the genomic DNA of transgenic plants was digested with XhoⅠ. Among them, there were four copies (about 17.7, 8, 5.5 and 4.7 kb in size) existing in all the tested plants of R3, R4 and R5 generations. The preliminary conclusion was that there were more than four copies of Bt toxin gene integrated into the genome of the cotton, among them, more than one copy can express and inherit steadily. This result provides a scientific basis for the breeding of the bivalent insect-resis- tant transgenic cotton plants and its commercialization.