Biology subjects

Urdampilleta, J.

Publications and source records attributed to Urdampilleta, J..

3 recordsLinked to original sources

bioRxiv2025

Exploring the Repetitive DNA Diversity in Solanum betaceum (Solanaceae)

The Solanaceae family, known for its diverse and economically important crops, includes the genus Solanum, which comprises 1,245 species. Solanum betaceum (tree tomato), native to the Andes and cultivated globally, is a promising species due to its nutritional value and market potential. The Cyphomandra clade, which includes the tree tomato, is characterized by huge genomes and chromosomes, with repetitive DNA elements (e.g., retrotransposons and satellite DNA) playing crucial roles in genomic and evolutionary studies. Despite its importance, genetic research on S. betaceum remains limited. This study addresses this knowledge gap by characterizing the repetitive DNA fraction to better understand intraspecific variation and develop molecular markers. Samples from five populations in northwestern Argentina were cultivated, and genome size was assessed via flow cytometry. Illumina HiSeq sequencing combined with RepeatExplorer analysis was used to identify repetitive DNA elements. Cytogenetic techniques, including CMA/DAPI staining and fluorescence in situ hybridization (FISH), were employed to detect satellite DNA patterns. Genome size analysis revealed slight variation among populations. Repetitive DNA accounted for 63.5% of the genome, with Ty3-gypsy retrotransposons being the most abundant (51.44%). Satellite DNA and rDNA were less prevalent, comprising 0.93% and 0.30% of the genome, respectively. Population comparisons showed consistent proportions of repetitive DNA overall, with notable differences in Ty3-gypsy-Tekay and satellite DNA fractions. This study provides a detailed profile of the repetitive DNA landscape in S. betaceum, uncovering intraspecific differences and delivering valuable genomic insights for future breeding and conservation efforts.

genomics↗

bioRxiv2025

Cytogenetic Insights of C. argentinana Yunk. and C. parodiana Yunk., two species from section Subulatae (Cuscuta L. - Convolvulaceae)

The genus Cuscuta exhibits remarkable cytogenetic diversity, strongly influenced by heterochromatin dynamics. The genus is divided into four subgenera, the subgenus Grammica is almost exclusively found in the Americas, and South America is the first major diversification center. The section Subulatae consists of species primarily found in Argentina. To cytogenetically characterize the Cuscuta species of Subulatae and investigate the chromosomal evolution of the subgenus Grammica, CMA/DAPI banding, FISH with 5S and 35S rDNA, and flow cytometry were performed on C. argentinana and C. parodiana. Both species exhibited 2n = 30 with differences in chromosome size, heterochromatic banding patterns, and genome size. Cuscuta argentinana has smaller chromosomes and genome (1C = 1.49 Gbp) and a higher number of metacentric chromosomes and CMA/DAPI- bands, whereas C. parodiana (1C = 2.79 Gbp) exhibits heterochromatin accumulation and a higher number of submetacentric chromosomes and heterochromatin accumulation. While the number of 5S rDNA sites was the same (six sites), C. parodiana presented one more pair of 35S rDNA sites. The results suggest that genome variation in Cuscuta section Subulatae is associated with heterochromatin amplification. These findings contribute to understanding of Grammica diversification and the role of heterochomatin in the chromosomal evolution of the genus.

plant biology↗

bioRxiv2024

Cytogenetic comparison of Cuscuta psorothamnensis and C. veatchii (Convolvulaceae), two species originated from recurrent hybridization between the same diploid parents

Genus Cuscuta L. (Convolvulaceae) exhibits cases of hybridization and allopolyploidy. Section Denticulatae, subg. Grammica, includes four species: the allopolyploids, C. veatchii and C. psorothamnensis (2n = 60), which originated from two independent reticulation events between the diploids, C. denticulata and C. nevadensis (2n = 30). The allopolyploids are morphologically similar, but are differing in their geographical distribution and host specificity. While cytogenetic data have been reported for C. veatchii, this study aims to provide a comparative analysis with C. psorothamnensis. To characterize the chromosomal complement of C. psorothamnensis and compare it with C. veatchii, we used CMA/DAPI banding, FISH, and GISH. The karyotypes of both species displayed similarity in chromosome number, size, and symmetry, and interphase nucleus organization. Both species exhibited a pair of 5S and 35S rDNA sites adjacent on the same chromosome. The number of 5S rDNA sites in C. psorothamnensis is variable, with some individuals displaying four, five, and six sites. Our results show: 1) the chromosomal pair carrying adjacent 5S and 35S rDNA in C. denticulata is retained in the polyploids; 2) the loss of C. nevadensis rDNA sites occurred in both tetraploids; 3) C. psorothamnensis and C. veatchii are allopolyploids part of a species complex, originated from successive independent hybridization events between C. denticulata and C. nevadensis; and 4) C. psorothamnensis is probably more recent in origin than C. veatchii based on the degree of diploidization. This cytogenetic comparison allows us to understand the processes involved in the emergence of new polyploid species by hybridization. Main ConclusionCuscuta psorothamnensis and C. veatchii form a complex of allopolyploid species originating from independent, successive hybridization events between C. denticulata and C. nevadensis.

plant biology↗