Biology subjects

Praveen, P.

Publications and source records attributed to Praveen, P..

3 recordsLinked to original sources

bioRxiv2026

Predominant tetraploidy and lack of ploidy-associated genetic structure across invasive Lantana camara populations in India

Polyploidization is widely recognised as a major driver of plant diversification, with many species persisting as mixed-ploidy systems where multiple cytotypes co-exist. Polyploids are disproportionately represented among invasive species, yet their role in facilitating biological invasions remains poorly understood. Lantana camara, one of the worlds most successful invasive plants, exhibits remarkable cytotype diversity, but the distribution and evolutionary relationships of these cytotypes in its native and invasive ranges have remained unclear. Here, we characterise ploidy variation and assess genetic differentiation among cytotypes in invasive L. camara populations across India. Flow cytometry of more than a thousand individuals reveals that tetraploids overwhelmingly dominate the invasive range, accounting for more than 95% of individuals, while triploids and hexaploids occur at much lower frequencies. Using genome-wide ddRAD-derived SNP markers from diploids, triploids, tetraploids, and hexaploids, we find no genetic differentiation among cytotypes. Instead, individuals of different ploidy levels cluster together across multiple genetic clusters, consistent with recurrent and potentially independent origins of polyploids. These patterns further suggest that L. camara polyploids likely arise via autopolyploid formation. Together, our results establish tetraploidy as the predominant cytotype in Indias invasive populations and reveal a lack of cytotype-specific genetic structure. These findings highlight the need to investigate the ecological advantages of tetraploids and the mechanisms that generate cytotype diversity, key steps toward understanding how polyploidy contributes to the invasive success of this globally important species.

evolutionary biology↗

bioRxiv2024

The population structure of invasive Lantana camara is shaped by its mating system

Over the last century, invasive species have emerged as an important driver of global biodiversity loss. Many invasive species have low genetic diversity in the invaded habitats, owing to the demographic bottleneck during introduction. Lantana camara is one of the hundred most problematic invasive species globally. Despite its ecological importance in many countries, our understanding of the genetic diversity patterns of this plant remains poor. Previous studies hypothesize that invasive L. camara is a species complex with a hybrid origin, though this has never been tested. We investigated the population genetic patterns of L. camara by sampling 359 plants that represented a spectrum of flower colour variants across 36 locations, spanning most of the biogeographic regions across India. Analyses of the population structure using 19,008 SNPs revealed that L. camara in India exhibits a strong genetic structure. Interestingly, the structuring pattern does not exhibit a strong correlation with geography. In the structure analysis, individuals with similar flower colours clustered together regardless of their location of origin. The genetic distance between most of the individuals was low, indicating the absence of multiple species. A high inbreeding coefficient and a low proportion of heterozygous sites observed suggested that the strong structure could be due to self-fertilization. This was further confirmed by bagging experiments, which demonstrated that L. camara is self-compatible in India. Thus, we infer that L. camara exists as homozygous inbred lines formed by self-fertilization and that these inbred lines could be associated with distinct flower colours. Together, this would explain the correlation between flower colour and genetic structure, and the lack of geographic structure. These results refute the argument that L. camara is a species complex and emphasize the importance of the mating system in shaping the patterns of diversity in this invasive species. Our findings highlight a hitherto unknown role for mating systems in invasive species, furthering our understanding of evolution in invasive species.

evolutionary biology↗

bioRxiv2023

Integrated spatial protein and RNA analysis on the same section using MICS technology

Spatial Biology has evolved from the molecular characterization of microdissected cells to high throughput spatial RNA and protein expression analysis at scale. The main limitation of spatial technologies so far is the inability to resolve protein and RNA information in the same histological section. Here, we report for the first time the integration of highly multiplexed RNA and protein detection on the same tissue section. We developed a new, automated, spatial RNA detection method (RNAsky), which is based on targeted rolling circle amplification and iterative staining. We combine RNAsky with MACSima Imaging Cyclic Staining (MICS) based protein analysis and show compatibility with subsequent standard hematoxylin and eosin (H&E) staining. Using both, open-source tools and our recently developed software suite MACS(R) iQ View, we demonstrate our multiomics MICS workflow by characterizing key immune-oncology markers at subcellular resolution across normal and diseased tissues.

molecular biology↗