How much genetic variation is stored in the endangered and fragmented shrub Tetraena mongolica Maxim?

Tetraena mongolica Maxim (Zygophyllaceae) is an endangered species endemic to western Inner Mongolia and China, and is currently threatened by habitat loss and human over-exploitation. We explored the genetic background, its genetic diversity, population structure, and demographic history, based on 12 polymorphic nuclear microsatellite loci. Our results indicated high genetic diversity in extant populations, but no distinguishable gene cluster corresponding with a specific biogeography. Population demography analysis using a MSVAR indicated a strong, recent population decline approximately 5,455 years ago. These results suggest that the Yellow River and Zhuozi Mountain range may not prevent pollination between populations. Finally, we surmised that the population demography of T. mongolica was likely to have been affected by early mankind activities

Identification of a novel thrombospondin-related anonymous protein (BoTRAP2) from Babesia orientalis

Abstract Background The thrombospondin-related anonymous protein (TRAP) was first discovered in the sporozoite of Plasmodium falciparum and TRAP family proteins are secreted by micronemes and transported to the parasite surface to participate in the invasion process. Various TRAP proteins have been identified in apicomplexan protozoans, but there have been few reports about TRAP proteins in Babesia orientalis. Methods The functional domain of TRAP2 in B. orientalis was cloned, sequenced, characterized and compared to the TRAP sequences of related apicomplexan parasites. The functional domain of BoTRAP2 was truncated, named BoTRAP2-1, and then cloned into the pET-28a expression vector. Rabbit anti-rBoTRAP2-1 polyclonal antibody was produced by immunizing three rabbits. Western blot analysis was used to identify the native form and immunogenicity of BoTRAP2. The localization of BoTRAP2 was identified by indirect fluorescence assay (IFA). Results The amplified genes of BoTRAP2 are 2817 bp in length, encoding a functional domain of about 938 aa with two vWFA domains, one TSP domain and one transmembrane domain. The amino acid sequence of BoTRAP2 has a high similarity with that of B. bovis and B. gibsoni. The predicted tertiary structure of truncated BoTRAP2-1 confirmed that BoTRAP2 contains two vWFA domains and a TSP domain, the main functional areas of the protein. The native BoTRAP2 was identified from B. orientalis lysate by using rabbit polyclonal anti-rBoTRAP2-1. A band corresponding to rBoTRAP2-1 was detected by reaction with serum from a B. orientalis-infected water buffalo, indicating that the protein has a high immunogenicity. IFA showed that BoTRAP2 is mainly localized on the apical end of parasites by rabbit anti-rBoTRAP2-1 polyclonal serum. Conclusions The rBoTRAP2 could differentiate serum from B. orientalis-infected water buffalo and normal water buffalo, implicating that BoTRAP2 has high immunogenicity and could serve as a candidate antigen for diagnosis of B. orientalis infection in buffalo

Recent advances in the application of MXenes for neural tissue engineering and regeneration

Transition metal carbides and nitrides (MXenes) are crystal nanomaterials with a number of surface functional groups such as fluorine, hydroxyl, and oxygen, which can be used as carriers for proteins and drugs. MXenes have excellent biocompatibility, electrical conductivity, surface hydrophilicity, mechanical properties and easy surface modification. However, at present, the stability of most MXenes needs to be improved, and more synthesis methods need to be explored. MXenes are good substrates for nerve cell regeneration and nerve reconstruction, which have broad application prospects in the repair of nervous system injury. Regarding the application of MXenes in neuroscience, mainly at the cellular level, the long-term in vivo biosafety and effects also need to be further explored. This review focuses on the progress of using MXenes in nerve regeneration over the last few years; discussing preparation of MXenes and their biocompatibility with different cells as well as the regulation by MXenes of nerve cell regeneration in two-dimensional and three-dimensional environments in vitro. MXenes have great potential in regulating the proliferation, differentiation, and maturation of nerve cells and in promoting regeneration and recovery after nerve injury. In addition, this review also presents the main challenges during optimization processes, such as the preparation of stable MXenes and long-term in vivo biosafety, and further discusses future directions in neural tissue engineering

A novel Babesia orientalis 135-kilodalton spherical body protein like: identification of its secretion into cytoplasm of infected erythrocytes

Abstract Background The spherical body is a distinct organelle only existing in Babesia and Theileria. Spherical body proteins (SBPs) are secreted from spherical bodies and incorporated into the cytoplasm of infected erythrocytes during invasion and post-invasion stages. Four different SBP homologues (SBP1, SBP2, SBP3 and SBP4) have been identified in Babesia bovis and Babesia bigemina. So far, there has been no report available about the identification of SBPs in Babesia orientalis. Methods The SBP3-like in B. orientalis (BoSBP3-like) was cloned, sequenced, characterized and compared to the SBP3 sequences of B. bovis and B. bigemina by bioinformatics analyses. The BoSBP3-like gene was truncated into three fragments: BoSBP3-like-1 (915 bp), BoSBP3-like-2 (1311 bp) and BoSBP3-like-3 (1011 bp), which were amplified and cloned into the expression vector pET-28a and expressed as three truncated recombinant (His-fusion) proteins. The immunogenicity, native forms and localization of BoSBP3-like were identified by western blot and indirect immunofluorescence assay (IFA). Results The BoSBP3-like gene was intronless with an open reading frame (ORF) of 3237 bp, encoded a 1079 amino acid polypeptide with a predicted size of 135 kDa, and contained a cysteine-rich region, three dispersing FAINT domains and a signal peptide (1–16 aa) at the N-terminus. The amino acid sequence of BoSBP3-like was 61.6 and 35.0% identical to that of B. bovis and B. bigemina, respectively. BoSBP3-like was identified as 135 kDa in the parasite lysate by rabbit antiserum against the truncated recombinant BoSBP3-like-1 (rBoSBP3-like-1). Three specific bands corresponding to rBoSBP3-like-1 (1–305 aa, 43 kDa), rBoSBP3-like-2 (306–742 aa, 58 kDa) and rBoSBP3-like-3 (743–1079 aa, 52 kDa) were detected by reaction with serum from B. orientalis-infected buffalo. The BoSBP3-like was not only localized in the spherical body of B. orientalis but also in the cytoplasm of infected erythrocytes of buffalo as puncta-like protein specks at both single and paired parasite development stages. Conclusions Through secretion into the cytoplasm of infected erythrocytes, BoSBP3-like may play a significant role in adaptation, interaction, and modification related to the host environment to benefit the growth and survival of Babesia. BoSBP3-like could react with the serum from B. orientalis-infected buffalo, but not healthy buffalo, implicating that BoSBP3-like is highly antigenic and may serve as a candidate diagnostic antigen for the detection of B. orientalis

Identification and molecular characterization of a novel Babesia orientalis thrombospondin-related anonymous protein (BoTRAP1)

Abstract Background The thrombospondin-related anonymous protein (TRAP) family, a kind of transmembrane protein, is widely distributed with a conserved feature of structure in all apicomplexan parasites and plays a crucial role in the gliding motility and survival of parasites. Methods The Babesia orientalis TRAP1 gene (BoTRAP1) was truncated and cloned into a pET-42b expression vector and expressed as a GST-tag fusion protein with a TEV protease site. Rabbit anti-rBoTRAP1 antibody was produced and purified using a protein A chromatography column. Western blot analysis was performed to identify the native protein of BoTRAP1 and differentiate B. orientalis-infected positive from negative serum samples. The localization of BoTRAP1 on merozoites was identified by the indirect florescent antibody test (IFAT). Results The partial sequence of the TRAP1 gene was cloned from B. orientalis cDNA and identified to contain a von Willebrand factor A (vWFA) region and a thrombospondin type-1 (TSP-1) domain; it had a length of 762 bp, encoding a polypeptide of 254 amino acid residues with a predicted size of 28.2 kDa. The partial sequence was cloned into a pET-42b expression vector and expressed in E. coli as a GST fusion protein. Western blot indicated that rBoTRAP1 has a high immunogenicity and can differentiate B. orientalis-infected positive and negative serum samples collected from water buffaloes. IFAT showed that BoTRAP1 is mainly localized on the apical end of intracellular parasites by using polyclonal antibodies (PcAb) against rBoTRAP1. Meanwhile, the PcAb test also identified the native BoTRAP1 as a ~65 kDa band from B. orientalis lysates. The predicted 3D structure of BoTRAP1 contains a metalion-dependent adhesion site (MIDAS), which could be important for interaction with ligand on the surface of the host cells. Conclusions Like all known protozoa, B. orientalis has a TRAP family, comprising TRAP1, TRAP2, TRAP3 and TRAP4. The newly identified and characterized BoTRAP1 may play a key role in the invasion of B. orientalis into water buffalo erythrocytes

Improvements in timber production of Chinese fir (Cunninghamia lanceolata) per unit forest area in China via tree breeding: Status and challenges

Chinese fir [Cunninghamia lanceolata (Lamb.) Hook] is a fast-growing tree species that is widely planted for timber production in southern China. Many high-quality breeding systems for Chinese fir have been developed using genetic methods. Here, we systematically review progress in increasing Chinese fir timber volumes per unit forest area in China, using genetic methods. We comprehensively assess the objec- tives, strategies, and primary accomplishments of the first to fourth generations of a Chinese fir breeding program. Furthermore, we propose a genetic improvement program and protocol for Chinese fir, and out- line several recommendations with respect to the main challenges associated with using genetic methods to increase timber yields. Finally, we present a series of proposals to increase Chinese fir timber production in China. This review offers insight into genetic improvements that have increased timber volumes of Chi- nese fir over four generations of breeding, and provides direction for future genetic improvements to wood properties

Characterization of a novel secretory spherical body protein in Babesia orientalis and Babesia orientalis-infected erythrocytes

Abstract Background The spherical body, a membrane bound organelle localized in the apical organelle complex, is unique to Babesia and Theileria spp. The spherical body proteins (SBPs) secreted by spherical bodies include SBP1, SBP2, SBP3 and SBP4. Up to now, only SBP3 has been characterized in Babesia orientalis. Methods The BoSBP4 gene was amplified from cDNA and gDNA and cloned into the pGEX-6P-1 vector by homologous recombination, sequenced and analyzed by bioinformatics tools. The amino acid (aa) sequence of BoSBP4 was compared with that of Babesia bovis and Babesia bigemina as well as SBP3 of B. orientalis. The immunoreactivity was evaluated by incubating recombinant BoSBP4 (rBoSBP4) with the serum of B. orientalis-infected water buffalo. The native form of BoSBP4 was identified by incubating lysate of B. orientalis-infected water buffalo erythrocytes with the anti-rBoSBP4 mouse serum. The cellular localization of BoSBP4 was determined by indirect immunofluorescence assay. Results The full length of the BoSBP4 gene was estimated to be 945 bp without introns, encoding a 314 aa polypeptide with a predicted molecular weight of 37 kDa. The truncated recombinant protein was expressed from 70 to 945 bp as a GST fusion protein with a practical molecular weight of 70 kDa. BoSBP4 shared a 40% and 30% identity with B. bovis and B. bigemina, respectively. Furthermore, it was 31% identical to SBP3 of B. orientalis. BoSBP4 was identified in the lysate of B. orientalis-infected water buffalo erythrocytes with a molecular weight of 37 kDa, corresponding to the expected molecular mass of BoSBP4. The result of rBoSBP4 with positive serum revealed that BoSBP4 can elicit an immune response to B. orientalis-infected water buffalo. The cellular localization of BoSBP4 was detected to be adjacent to the merozoite nucleus in the intracellular phase, followed by the diffusion of the fluorescence of BoSBP4 into the cytoplasm of B. orientalis-infected erythrocytes as puncta-like specks and a gradual increase of the fluorescence. Conclusions In this study, SBP4 in B. orientalis was characterized for the first time. It may play a key role in interaction with the host cell by being secreted into the cytoplasm of the B. orientalis-infected erythrocytes to facilitate parasite growth and reproduction

The BORDER family of negative transcription elongation factors regulates flowering time in Arabidopsis

Transcription initiation has long been considered a primary regulatory step in gene expression. Recent work, however, shows that downstream events, such as transcription elongation, can also play important roles.1-3 A well-characterized example from animals is promoter-proximal pausing, where transcriptionally engaged Pol II accumulates 30-50 bp downstream of the transcription start site (TSS) and is thought to enable rapid gene activation.2 Plants do not make widespread use of promoter-proximal pausing; however, in a phenomenon known as 3' pausing, a significant increase in Pol II is observed near the transcript end site (TES) of many genes.4-6 Previous work has shown that 3' pausing is promoted by the BORDER (BDR) family of negative transcription elongation factors. Here we show that BDR proteins play key roles in gene repression. Consistent with BDR proteins acting to slow or pause elongating Pol II, BDR-repressed genes are characterized by high levels of Pol II occupancy, yet low levels of mRNA. The BDR proteins physically interact with FPA,7 one of approximately two dozen genes collectively referred to as the autonomous floral-promotion pathway,8 which are necessary for the repression of the flowering time gene FLOWERING LOCUS C (FLC).9-11 In early-flowering strains, FLC expression is repressed by repressive histone modifications, such as histone H3 lysine 27 trimethylation (H3K27me3), thereby allowing the plants to flower early. These results suggest that the repression of transcription elongation by BDR proteins may allow for the temporary pausing of transcription or facilitate the long-term repression of genes by repressive histone modifications