scholarly journals Animal chromosome counts reveal similar range of chromosome numbers but with less polyploidy in animals compared to flowering plants

2020 ◽  
Author(s):  
Cristian Román-Palacios ◽  
Cesar A. Medina ◽  
Shing H. Zhan ◽  
Michael S. Barker
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Chromosome Evolution ◽  
Chromosome Count ◽  
Flowering Plants ◽  
Similar Distribution ◽  
Chromosome Counts ◽  
Remarkable Similarity ◽  
Similar Range

AbstractUnderstanding the mechanisms that underlie chromosome evolution may provide insights into the processes underpinning the origin, persistence, and evolutionary tempo of lineages. Here we present the first database of chromosome counts for animals (the Animal Chromosome Count database, ACC) summarizing chromosome numbers for ∼18,000 species. We found remarkable similarity in the distribution of chromosome counts between animals and flowering plants. At larger timescales, selection towards a specific range might explain the similar distribution of chromosome counts between these two groups. Nevertheless, changes in chromosome number are still potential drivers of divergence among species at shorter timescales. We also found that while animals and plants exhibit similar frequencies of speciation-related changes in chromosome number, plant speciation is more often related to changes in ploidy. Based on the ACC, our analyses suggest that changes in chromosome number alone could help explain patterns of diversity within animal clades.

The chromosome numbers of five North American and European leech species

1987 ◽  
Vol 65 (3) ◽  
pp. 681-684 ◽  
Author(s):  
Ronald W. Davies ◽  
R. N. Singhal
Keyword(s):  
Chromosome Number ◽  
North American ◽  
Chromosome Numbers ◽  
Chromosome Evolution ◽  
Chromosome Counts ◽  
Prophase I ◽  
Metaphase I

Chromosome counts were obtained for four glossiphoniid species belonging to three genera (Glossiphonia, Theromyzon, Placobdella) and for one erpobdellid species (Dina lineata) of freshwater leeches. Theromyzon rude, which has a Palaearctic distribution, had seven bivalents at prophase I and metaphase I, while the Holarctic T. tessulatum had eight bivalents, giving diploid chromosome numbers of 14 and 16, respectively. Placobdella papillifera from Alberta had a chromosome number of 2n = 24 and Glossiphonia complanata from Alberta and England had chromosome counts of 2n = 28. At prophase I and metaphase I nine bivalents occurred in the majority of the nuclei of Dina lineata. These findings are discussed in relation to the chromosome evolution and phylogenetic schemes proposed by previous authors.

Chromosome evolution in Bulbine glauca (Asphodelaceae or Xanthorrhoeaceae subfam. Asphodeloideae) indicates six species, not one

2016 ◽  
Vol 64 (3) ◽  
pp. 206 ◽  
Author(s):  
Iain S. F. Moore ◽  
Elizabeth A. Brown ◽  
Ian R. H. Telford ◽  
Jeremy J. Bruhl
Keyword(s):  
Chromosome Numbers ◽  
Chromosome Evolution ◽  
New South ◽  
Chromosome Count ◽  
Chromosome Morphology ◽  
Morphological Evidence ◽  
Chromosome Counts ◽  
South Wales ◽  
Granite Outcrops ◽  
Evolutionary Changes

The genus Bulbine Wolf has ~130 species in Africa and only seven species in Australia. Base chromosome numbers in African and Australian Bulbine are x = 7 and x = 12, respectively. This raises the possibility of Australian Bulbine being of polyploidy origin or, alternatively African Bulbine may have evolved through dysploid reduction. Previous chromosome counts in Bulbine glauca (Raf.) E.M.Watson were predominantly 2n = 46, with aneuploid numbers of 2n = 45, 44, 48, 47, 40 and 41 also being encountered within and between populations. Novel chromosome counts are presented here for a wide sample of populations of B. glauca, occurring on volcanic and granite outcrops along the New South Wales and Victorian tablelands and on granite outcrops in Tasmania. Chromosome numbers for Bulbine crassa D.I.Morris and Duretto is 2n = 26. The modal chromosome count for B. glauca is confirmed as 2n = 46 with no evidence of aneuploidy. The species complex shows a variable asymmetric karyotype across its distribution, indicating karyotypic evolution involving structural rearrangements. There appear to be six distinctive groups within the complex based on karyomorphology. Evolutionary changes in both B. glauca s. lat. and B. crassa appear to have not involved recent polyploidy. Variation in chromosome morphology across the B. glauca complex is consistent with our morphological evidence of more than one species.

scholarly journals Limitation of current probe design for oligo-cross-FISH, exemplified by chromosome evolution studies in duckweeds

Chromosoma ◽  
2021 ◽  
Vol 130 (1) ◽  
pp. 15-25
Author(s):  
Phuong T. N. Hoang ◽  
Jean-Marie Rouillard ◽  
Jiří Macas ◽  
Ivona Kubalová ◽  
Veit Schubert ◽  
...  
Keyword(s):  
Growth Rate ◽  
Chromosome Number ◽  
Chromosome Evolution ◽  
Sequence Similarity ◽  
Flowering Plants ◽  
The Other ◽  
Probe Design ◽  
Congeneric Species ◽  
Specific Design ◽  
Spirodela Polyrhiza

AbstractDuckweeds represent a small, free-floating aquatic family (Lemnaceae) of the monocot order Alismatales with the fastest growth rate among flowering plants. They comprise five genera (Spirodela, Landoltia, Lemna, Wolffiella, and Wolffia) varying in genome size and chromosome number. Spirodela polyrhiza had the first sequenced duckweed genome. Cytogenetic maps are available for both species of the genus Spirodela (S. polyrhiza and S. intermedia). However, elucidation of chromosome homeology and evolutionary chromosome rearrangements by cross-FISH using Spirodela BAC probes to species of other duckweed genera has not been successful so far. We investigated the potential of chromosome-specific oligo-FISH probes to address these topics. We designed oligo-FISH probes specific for one S. intermedia and one S. polyrhiza chromosome (Fig. 1a). Our results show that these oligo-probes cross-hybridize with the homeologous regions of the other congeneric species, but are not suitable to uncover chromosomal homeology across duckweeds genera. This is most likely due to too low sequence similarity between the investigated genera and/or too low probe density on the target genomes. Finally, we suggest genus-specific design of oligo-probes to elucidate chromosome evolution across duckweed genera.

scholarly journals New Contribution to the Knowledge on the Chromosome Numbers of Turkish Cerambycidae (Coleoptera)

2021 ◽  
Vol 69 (2) ◽  
pp. 93-99
Author(s):  
Yavuz Koçak ◽  
Elmas Yağmur
Keyword(s):  
Chromosome Number ◽  
Sex Determination ◽  
Chromosome Numbers ◽  
Chromosome Count ◽  
Chromosomal Number ◽  
The Poor ◽  
Karyological Data ◽  
First Time

Information on the karyotypes of Turkish species of Cerambycidae is scanty. Our study contributes to the knowledge of the karyological data (chromosomal number and mechanism of sex determination) of five Turkish longicorn beetles; karyotypes of four taxa, one endemic, are described for the first time and for the remaining one, Purpuricenus budensis (Götz, 1783), the previously published chromosome count is confirmed. The chromosome number of Purpuricenus desfontainii inhumeralis Pic, 1891 and Purpuricenus budensis (Götz, 1783) (Cerambycinae, Trachyderini) was found to be 2n = 28 (13 + Xyp); Clytus rhamni Germar, 1817 and Plagionotus floralis (Pallas, 1773) (Cerambycinae, Clytini) 2n = 20 (9 + Xyp); and the endemic Dorcadion triste phrygicum Peks, 1993 (Lamiinae, Dorcadionini) 2n = 24 (11 + Xyp). In view of the paucity of data available until now, our study is important for both to improve the poor karyological knowledge of Turkish Cerambycidae and to provide an incentive for other researchers.

scholarly journals Unprecedented reorganization of holocentric chromosomes provides insights into the enigma of lepidopteran chromosome evolution

2019 ◽  
Vol 5 (6) ◽  
pp. eaau3648 ◽  
Author(s):  
Jason Hill ◽  
Pasi Rastas ◽  
Emily A. Hornett ◽  
Ramprasad Neethiraj ◽  
Nathan Clark ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Chromosome Evolution ◽  
Chromosome Structure ◽  
Holocentric Chromosomes ◽  
Chromosome Counts ◽  
Pieris Napi ◽  
Haploid Chromosome Number ◽  
Genome Wide ◽  
The Face ◽  
Chromosome Level

Chromosome evolution presents an enigma in the mega-diverse Lepidoptera. Most species exhibit constrained chromosome evolution with nearly identical haploid chromosome counts and chromosome-level gene collinearity among species more than 140 million years divergent. However, a few species possess radically inflated chromosomal counts due to extensive fission and fusion events. To address this enigma of constraint in the face of an exceptional ability to change, we investigated an unprecedented reorganization of the standard lepidopteran chromosome structure in the green-veined white butterfly (Pieris napi). We find that gene content in P. napi has been extensively rearranged in large collinear blocks, which until now have been masked by a haploid chromosome number close to the lepidopteran average. We observe that ancient chromosome ends have been maintained and collinear blocks are enriched for functionally related genes suggesting both a mechanism and a possible role for selection in determining the boundaries of these genome-wide rearrangements.

Chromosome numbers of 15 North American bumble bee species (Hymenoptera, Apidae, Bombini)

1983 ◽  
Vol 25 (1) ◽  
pp. 26-29
Author(s):  
Robin E. Owen
Keyword(s):  
Chromosome Number ◽  
North American ◽  
Chromosome Numbers ◽  
Bumble Bees ◽  
Bumble Bee ◽  
Morphological Divergence ◽  
Chromosome Counts ◽  
Monophyletic Origin ◽  
The Social

Chromosome counts were obtained for 14 Bombus Latr. species (the social bumble bees) belonging to four subgenera and for one Psithyrus Lep. species (the social parasitic bumble bees). In Bombus the haploid numbers were consistent within each subgenus and there was variation between subgenera; the subgenera Bombus s.s. and Pyrobombus have n = 18, while Separatobombus and Cullumanobombus have n = 19. Thus considerable morphological divergence between subgenera is often, but not always, paralleled by divergence in chromosome number. Psithyrus ashtoni has n = 25, higher than all Bombus species yet examined. This provides support for the monophyletic origin of Psithyrus, but the high n is not expected if eusociality selects for increase in chromosome number.

scholarly journals A report on new chromosome number of three Dioscorea species

2019 ◽  
Vol 6 (2) ◽  
pp. 147-150
Author(s):  
Chiranjit Paul ◽  
Bimal Debnath
Keyword(s):  
Chromosome Number ◽  
Somatic Chromosome ◽  
Chromosome Count ◽  
Somatic Chromosome Number ◽  
Chromosome Counts ◽  
North East India ◽  
North East ◽  
Forest Belts ◽  
Dioscorea Species ◽  
First Time

Chromosomal study conducted in nine species of Dioscorea from different forest belts of Tripura revealed that their somatic chromosome number ranged from 2n=40 to 2n=60. The record of 2n=40 chromosome in the sexual phenotypes of Dioscorea hamiltonii, Dioscorea glabra and Dioscorea pubera are the first time report from Tripura, North East India. Moreover the somatic chromosome counts of 2n=60 in Dioscorea pentaphylla would be attributed as a new cytotype. However at the respective ploidy level no difference in somatic chromosome count was observed between their sexes.

CYTOLOGICAL STUDIES IN THE GENUS ERIGERON

1960 ◽  
Vol 38 (3) ◽  
pp. 381-386 ◽  
Author(s):  
F. H. Montgomery ◽  
Shung-Jun Yang
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Large Area ◽  
Chromosome Counts

The literature relating to the chromosome numbers in the genus Erigeron has been reviewed, and all reported numbers are given. The chromosome number for E. breweri var. porphyreticus (Jones) Cronquist, 2n = 18; E. divergens var. cinereus A. Gray, 2n = 27; E. glabellus var. glabellus Cronquist, 2n = 36; E. glabellus var. pubescens (Hook.) Cronquist, 2n = 36; E. hyssopifolius Michx., 2n = 18; E. quercifolia Lam., 2n = 36; E. simplex Greene, 2n = 27; E. strigosus var. beyrichii (Fisch. & Mey.) A. Gray, 2n = 27; and E. vernus T. & G., 2n = 18 are new determinations. Different numbers from those previously reported have been found for E. pulchellus Michx., 2n = 27, and E. strigosus (Muhl.) Willd., 2n = 36. Chromosome counts over a large area of their distribution have been made for E. annuus (L.) Pers., E. pulchellus Michx., E. philadelphicus L., and E. strigosus (Muhl.) Willd.

scholarly journals Chromosome number and meiotic behavior in several plant taxa from iran

2021 ◽  
Vol 45 (2) ◽  
pp. 333-339
Author(s):  
Seyed Ghaffari ◽  
Abbas Zare ◽  
Fereshteh Corom ◽  
Masoureh Sedaghati
Keyword(s):  
Chromosome Number ◽  
Endemic Species ◽  
Chromosome Numbers ◽  
Mitotic Chromosome ◽  
Vascular Plant ◽  
Meiotic Behavior ◽  
Chromosome Counts ◽  
Plant Families ◽  
First Time ◽  
Accessory Chromosomes

Original meiotic or both meiotic and mitotic chromosome numbers are reported for ten endemic and one non endemic species in nine vascular plant families from Iran. The chromosome numbers of Acantholimon schahrudicum, A. truncatum, Anthochlamys multinervis, Campanula perpusilla, Cousinia calcitrapa var. interrupta, Dorema ammoniacum, Euphorbia gedrosiaca, and Hyocyamus orthocarpus were determined for the first time. The chromosome counts for Astrodaucus persicus and Hedysarum criniferum agree with previous ones. The gametic chromosome numbers for Hedysarum criniferum and Allium stipitatum are reported here for the first time. The occurrence of accessory chromosomes are also reported for Acantholimon schahrudicum and Dorema ammoniacum, being the first records of B chromosomes in the genera Acantholimon and Dorema.

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