FISH Mapping of Telomeric and Non-Telomeric (AG3T3)3 Reveal the Chromosome Numbers and Chromosome Rearrangements of 41 Woody Plants

Abstract

Data for the chromosomal FISH mapping localization of (AG3T3)3 are compiled for 37 species belonging 27 families; for 24 species and 14 families, this is the first such report. The chromosome number and length ranged from 14–136 and 0.56–14.48 μm, respectively. A total of 23 woody plants presented chromosome length less than 3 μm, thus belonging to the small chromosome group. Telomeric signals were observed at each chromosome terminus in 38 plants (90.5%) and were absent at several chromosome termini in only four woody plants (9.5%). Non-telomeric signals were observed in the chromosomes of 23 plants (54.8%); in particular, abundant non-telomeric (AG3T3)3 was obviously observed in Chimonanthus campanulatus. Telomeric signals outside of the chromosome were observed in 11 woody plants (26.2%). Overall, ten (AG3T3)3 signal pattern types were determined, indicating the complex genome architecture of the 37 considered species. The variation in signal pattern was likely due to chromosome deletion, duplication, inversion, and translocation. In addition, large primary constriction was observed in some species, probably due to or leading to chromosome breakage and the formation of new chromosomes. The presented results will guide further research focused on determining the chromosome number and disclosing chromosome rearrangements of woody plants.

Karyotype Description and Comparative Chromosomal Mapping of 5S rDNA in 21 species

“…(2n = 28), P. cyrtonema (2n = 22) (Sun 1996, Chen and Zhou 2005); ii ) Zanthoxylum acanthopodium Candelle (2n = 64), Zanthoxylum dimorphophyllum Hemsley (2n = 36/68), Zanthoxylum scandens Blume (2n = 68), Zanthoxylum oxyphyllum Edgeworth (2n = 72), Zanthoxylum tomentellum J.D. Hance (2n = 72), Zanthoxylum simulans Hance (2n =∼132, Z. nitidum (2n = 68), Z. armatum (2n = 66/98/128/132/136), Z. bungeanum (2n = 132/136) (Zhang and Hartley 2008, Chen et al 2009, Yu et al 2010, Luo et al 2018d, Luo et al 2022b, He et al 2023, Hu et al 2023); iii ) Bletilla formosana (2n = 32/36), B. striata (2n = 32/34/36/48/51/64/76), B. ochracea (2n = 34/36) (Miduno 1954, He et al 2022c, Huan et al 2022, Yang et al 2023); iv ) J. regia and J. sigillata (2n = 34) (Luo and Chen 2020), Juglans (2n = 32) (Woodworth 1930, Hans 1970, Tulecke et al 1988, Mu and Xi 1988, Mu et al 1990). In this study, P. cyrtonema (2n = 18), Z. bungeanum (2n = 76/134/136/160), Z. armatum (2n = 96/100/102/104/132), Z. nitidum (2n = 66), B. formosana, B. striata , B. ochracea , J. regia, and J. sigillata (all 2n = 34).…”

“…The species used for this experiment were chosen due to the discovery of karyotype realignments (Luo et al 2017, Luo et al 2018d, Liu and Luo 2019, Luo and Liu 2019, Luo ang Chen 2019, 2020, Luo and He 2021, Luo et al 2022a, b, He et al 2022a, b, c, 2023). Because these species were checked, their 5S rDNA has not yet been explored.…”

“…The patent oligonucleotide FISH (Oligo-FISH) technology is widely problematic in related cytogenetic investigations compared to conventional FISH analysis because of its low cost (Beliveau et al 2012). Moreover, based on available DNA sequencing data, oligonucleotide probes (Oligo-probe) have been developed and successfully applied to many plants (He et al 2020, Xin et al 2020, Luo et al 2022a, b, He et al 2023). Therefore, examining the 5S rDNA sites by Oligo-FISH would efficiently contribute to further cytogenetic research on the 64 plants.…”

Telomeres and Their Neighbors

“…With large amounts of genomic data now available and easily accessible, predicting or verifying laboratory experiments with in silico work is now an increasingly more sensible plan that should be accessible to any laboratory. Equally, as knowledge of telomeres and particularly subtelomeric satellites expands, it is apparent that open-access databases of this knowledge, particularly the results from karyotyping studies [ 151 , 167 ], would benefit the research community as a whole and make such data more visible and manageable. There are still many unanswered questions in satellite research making this an inviting topic for the open-minded researcher.…”

“…When such clusters are big enough, these can be detected by FISH ( Figure 2 d–f) and distinguished from telomeres (e.g., [ 49 , 157 , 159 , 164 , 165 , 166 , 167 , 168 , 169 ]). If they are shorter than the detection limit of this method, they can still show a positive signal when investigated by Southern hybridization or primer extension ( Figure 2 g).…”