Genetics and Molecular Biology最新文献

Dichrocephala benthamii C. B. Clarke has long been used as traditional Chinese medicine. However, the chloroplast (cp) genome of D. benthamii is poorly understood so far. In this study, we sequenced and analyzed the cp genome of D. benthamii. The results showed that the cp genome is 152,350 bp in length, with a pair of inverted repeat regions (IRa and IRb, each 24,982 bp), a large single-copy (LSC) region comprising 84,136 bp, and a small single-copy (SSC) region comprising 18,250 bp. The GC content of the cp genome was 37.3%. A total of 134 genes were identified, including 87 protein-coding genes (CDS), 38 tRNA genes, 8 rRNA genes, and 1 pseudogene (ycf1). Expansion or contraction of IR regions were detected in D. benthamii and other species of the tribe Astereae. Additionally, our analyses showed the types of sequence repeats and the highly variable regions discovered by analyzing the border regions, sequence divergence, and hot spots. The phylogenetic analysis revealed D. benthamii is the basal group of Astereae. The results of this study will be a significant contribution to the genetics and species identification related to D. benthamii.

Neotropical fishes emerge as an extremely diverse group of vertebrates where genomic strategies to evaluate structural and functional features are still beginning. Here, we present a second draft genome of Apareiodon sp. (2n=54, ZZ/ZW), adding PacBio technology whole genome sequencing, and assembling by combining two technologies (long and short reads). Using a detailed strategy for genome assembly with fish genomes of Pygocentrus nattereri, Carassius auratus, and Astyanax mexicanus as references, the final assembly of the Apareiodon sp. genome generated 93 scaffolds, an N50 of 37,200,078 bases, and a size estimate considering 28 scaffolds (26 autosomes+ZW) of ~945 Mb. In Apareiodon sp., this second genome draft confirmed that ~36% of the genome is composed of repetitive DNA. Furthermore, the new draft genome has improved genomic quality assessments, allowing the annotation of 36,290 genes and 15,683 proteins, which presented similarities to reference genomes. The second draft genome of Apareiodon sp. will be useful for research on integrative cytogenetic and genomic data. It will open perspectives for analyzing sex-determining genes in Neotropical fish with a ZZ/ZW sex chromosome system.

The review explores parasitic plants' evolutionary success and adaptability, highlighting their widespread occurrence and emphasizing the role of an invasive organ called haustorium in nutrient acquisition from hosts. It discusses the genetic and physiological adaptations that facilitate parasitism, including horizontal gene transfer, and the impact of environmental factors like climate change on these relationships. It addresses the need for further research into parasitic plants' genomes and interactions with their hosts to better predict environmental changes' impacts.

Pedicularis L., a generally bothersome genus of hemiparasitic plants, is primarily native to southwestern China. The phylogenetic relationship and evolutionary history of this genus have not yet been fully resolved. In this study, we sequenced and assembled chloroplast genomes of three Pedicularis species, P. chinensis, P. melampyriflora, and P. striata using high-throughput Illumina sequencing. The assembled plastomes were 142,059 bp (P. chinensis) to 152,146 bp (P. striata) in size, containing 110 (P. chinensis) to 117 (P. striata) genes. Moreover, we identified 13-15 pseudogenes within the three plastomes, nine of which were pseudogenized in all three species. The three plastomes exhibited a similar codon usage pattern. Moreover, the plastomes contained abundant simple sequence repeats and long repeats, which showed slight variations between the three species. A maximum likelihood analysis was performed to elucidate the phylogenetic positions of the three species within the Pedicularis genus. The plastomes presented in our study can be used as valuable genomic resources for further genetic and genomic studies of the Pedicularis genus.

The catalytic, regulatory and structural properties of RNA, combined with their extraordinary ubiquity in cellular processes, are consistent with the proposal that this molecule played a much more conspicuous role in heredity and metabolism during the early stages of biological evolution. This review explores the pivotal role of RNA in the earliest life forms and its relevance in modern biological systems. It examines current models that study the early evolution of life, providing insights into the primordial RNA world and its legacy in contemporary biology.

Neuroblastoma (NB) is a solid tumor that accounts for 15% of all pediatric oncological deaths, and much is due to the low response to therapy in relapsed tumors. High-risk NB may present deletions in chromosome 11q, which may be associated with other chromosomal alterations and a poor response to therapy, but this association is still poorly understood. Using a systems biology network approach, we studied three patients with high-risk NB with deleted 11q stage 4 to highlight the connections between treatment resistance and copy number alterations in distinct cases. We built different protein-protein interaction networks for each patient based on protein-coding genes mapped at the cytobands pre- and post-chemotherapy from distinct copy number alterations data. In the post-chemotherapy networks, we identified five common regulatory nodes corresponding to the gained region located in ch17q:BIRC5, BRCA1, PRKCA, SUMO2, andGPS1. A crosslink between DNA damage and chromatin remodeling proteins was also found - a connection still poorly understood in NB. We identified a potential connection between XPB gain and chemoresistance of NB. The findings help elucidate the molecular profiles of high-risk NB with 11q deletion in pre- and post-chemotherapy tumor samples, which may reflect unique profiles in poor response to treatment.

In South America, Tambaqui (Colossoma macropomum) stands as the primary target for aquaculture, yet breeding programs for this Amazon native species are in their early stages. While high-density single nucleotide polymorphism (SNP) arrays are pivotal for aquaculture breeding, their costs can be prohibitive for non- or semi-industrial species. To overcome this, a cost-effective approach involves developing low-density SNP arrays followed by genotype imputation to higher densities. In this study, a 1K SNP array for tambaqui was created and validated, offering a balance between SNP quantity and genome representativity. The imputation accuracy from various SNP densities to a medium-density array was evaluated, with the 1K density demonstrating the best trade-off (accuracy of 0.93). This subset was further utilized to construct a commercial array through Agriseq™ targeted genotyping-by-sequencing, validated in 192 DNA samples, affirming its high quality for genotyping tambaqui. The low-density SNP array, with genome-wide coverage and high polymorphism, emerges as an effective tool for exploring genetic variation within diverse populations. Population analyses using the 1K panel proved to be an efficient tool for genetic characterization of sampled broodstocks, making it a valuable resource for genetic improvement programs targeting this Amazon native species.

Effector proteins in Phakopsora pachyrhizi (Pp), the causative agent of Asian Soybean rust, are involved in the infection process. A previous study identified a rust effector Egh16-like family based expression profile during the interaction with soybean. Herein, we scrutinized available the Pp genomes to validate the predicted Egh16-like family of Pp and identify new family members. We described 22 members of the Egh16-like gene family in the Pp MT2006 genome and 18 in the UFV02 and K8108 genomes, highlighting a family expansion. Family members have a small signal peptide, conserved cysteine-rich R/Y/FxC motifs in the C-terminal region, and a virulence-related Egh16-like domain and were able to suppress PTI related responses in Benthamiana. Phylogenetic analysis placed the family members into eight clusters, with members induced during the early stages of rust infection. Members of clusters VI and VII are present in different copy numbers in Pp genomes and suppressed PAMP-related responses.