Genes

Background/Objectives: The PB family of “cut-and-paste” DNA transposons shows great promise as genetic manipulation tools while significantly impacting eukaryotic genome evolution. However, their evolutionary profile in beetles (Coleoptera), the most species-rich animal order, remains poorly characterized. Methods: A local tBLASTN search was conducted to mine PiggyBac (PB) transposons across 136 coleopteran insect genomes, using the DDE domain of the PB transposase as the query. Multiple sequence alignment was performed with MAFFT, and a maximum likelihood phylogenetic tree of the transposase DDE domains was constructed using IQ-TREE. Evolutionary dynamics were analyzed by means of K-divergence. Results: Our study reveals PB transposons are widely distributed, highly diverse, and remarkably active across beetles. We detected PB elements in 62 of 136 examined species (45%), classifying them into six distinct clades. A total of 62 PB-containing species harbored intact copies, with most showing recent insertions (K divergence ≈ 0), indicating ongoing transpositional activity. Notably, PB elements from Harmonia axyridis, Apoderus coryli, and Diabrotica balteata exhibit exceptional potential for genetic tool development. Structurally, intact PB elements ranged from 2074 to 3465 bp, each containing a single transposase ORF (500–725 aa). All were flanked by terminal inverted repeats and generated TTAA target site duplications. Conclusions: These findings demonstrate PB transposons have not only shaped historical beetle genome evolution but continue to drive genomic diversification, underscoring their dual significance as natural genome architects and promising biotechnological tools.

Background/Objectives: Knee osteoarthritis (KOA) is a multifactorial and degenerative disease. Growth differentiation factor 5 (GDF5) polymorphism rs143384 G > A is associated with reduced gene expression and musculoskeletal pathologies. This study aimed to evaluate the association between this functional polymorphism and clinical variability and disease severity among patients with KOA in an admixed population. Methods: This cross-sectional observational study enrolled 224 Brazilian patients with KOA, who were evaluated and classified according to disease severity. Results: The median age was 64 (44–84) years; 75.9% of the patients were female, 50.9% were shorter than 1.60 m, and 67.4% were obese or morbidly obese. The disease severity distribution was 64.7% grades I–III and 35.3% IV–V. Patients with KOA who were over 70 years had significantly more advanced grades (OR = 9.3; 95% CI = 3.4–26), in either female group (OR = 8.2; 95% CI = 2.6–26). The minor allele frequency of the GDF5 rs143384 A variant was 41.7% in the overall KOA case group, increasing with disease severity (39.7% in grades I–III versus 45.6% in IV–V). After adjusting for the confounding factors (age and BMI) the GDF5 GA + AA genotype was significantly associated with higher KOA severity IV–V in female patients (OR = 2.5; 95% CI = 1.2–5.3). Additionally, the mean height of female KOA patients with the GDF5 GA + AA genotype (1.56 ± 0.07 m) was significantly shorter than that of patients with the GG genotype (1.59 ± 0.08 m). Conclusions: The GDF5 rs143384 polymorphism was associated with greater KOA severity and shorter stature in female patients. These results suggest that this variant may contribute to phenotypic variability in patients with knee osteoarthritis, helping to refine clinical characterization and stratification in this population, contributing to personalized diagnoses and guiding future changes in treatment guidelines for knee osteoarthritis.

Background: Kenaf (Hibiscus cannabinus L.) is an important fiber crop belonging to the genus Hibiscus in the Malvaceae family. Research on its chloroplast genome holds significant importance for deciphering the evolutionary relationships of the Hibiscus species, developing genetic markers, and promoting kenaf (H. cannabinus) genetic breeding. Methods: Based on high-throughput sequencing technology, this study completed the sequencing and assembly of the kenaf (H. cannabinus) chloroplast genome. Results: (1) The kenaf (H. cannabinus) chloroplast genome exhibits a typical circular quadripartite structure with a total length of 163,019 bp, including a large single-copy region (LSC) of 90,467 bp, a small single-copy region (SSC) of 19,486 bp, and a pair of inverted repeat regions (IRa/IRb) of 26,533 bp each. The total GC content is 36.62%, among which, the IR region has the highest GC content (42.61%) and the SSC region the lowest (30.87%). (2) A total of 131 genes were annotated, including 85 mRNAs, 37 tRNAs, 8 rRNAs, and 1 pseudogene. Their functions cover photosynthesis (e.g., pet and atp family genes), self-replication (e.g., rpl, rps, and rpo family genes), and genes with unknown functions (e.g., ycf1 and ycf2). A codon usage bias analysis revealed that the relative synonymous codon usage (RSCU) value of the stop codon UAA is the highest (1.6329), and codons ending with A/U are preferentially used (e.g., GCU for alanine with RSCU = 1.778). (3) A repeat sequence analysis identified various interspersed repeat sequences (predominantly 30~31 bp in length, with a relatively high proportion in the 30~40 bp range, including forward and palindromic types) and simple sequence repeats (cpSSRs). Among them, single-base repeat SSRs account for the highest proportion (e.g., (A)8 and (T)9), and specific SSR primers were designed. (4) A comparative evolutionary analysis indicated that the Ka/Ks ratios (nonsynonymous substitution rate/synonymous substitution rate) of core chloroplast genes (e.g., rps2 and rpoC2) in kenaf (H. cannabinus) are all less than 1 (0.145~0.415), suggesting that they are under purifying selection. The collinearity similarity of chloroplast genomes between kenaf (H. cannabinus) and its closely related species reaches over 99.97%, and the IR region boundaries are relatively conserved. The phylogenetic tree shows that kenaf (H. cannabinus) clusters with closely related Hibiscus species with a 100% bootstrap value, indicating a close genetic relationship. Conclusions: This study provides basic data for the functional analysis of the kenaf (H. cannabinus) chloroplast genome, the phylogeny of Hibiscus, and the utilization of genetic resources.