Highly divergent karyotypes and barcoding of the East African genus Gonatoxia Karsch (Orthoptera: Phaneropterinae)

Identification of chromosome ploidy and karyotype analysis of cherries (Prunus pseudocerasus Lindl.) in Guizhou

The present study aimed to characterize the chromosome features of cherry (Prunus pseudocerasus Lindl.) germplasm in Guizhou Province, China, in order to facilitate the selection and breeding programs of this economically and ornamentally valuable species. The stem tip chromosome preparation technique was employed for ploidy identification and karyotype analysis, and the results were further validated by flow cytometry. The findings revealed that the 28 cherry accessions from Guizhou province exhibited a chromosomal base of x = 8, comprising 19 tetraploid and nine hexaploid individuals. Karyotype analysis showed two chromosome types, "m" and "sm," with the longest chromosome/shortest chromosome (Lc/Sc) ranging from 1.6 to 2.65, the mean arm ratio (MAR) varying from 1.15 to 1.56, and index of the karyotypic asymmetry (As.K) ranging from 53.74 to 61.6. Three karyotype types, "1A," "1B," and "2B," were identified among the studied accessions. The most evolutionarily advanced accession was HZ152, while DCZC27 represented the most primitive karyotype. This study expands the ploidy database of Chinese cherry and provides valuable information for the conservation and utilization of cherry germplasm resources in Guizhou province.

Telomere Length Variation in Model Bryophytes

The ends of linear chromosomes of most eukaryotes consist of protein-bound DNA arrays called telomeres, which play essential roles in protecting genome integrity. Despite general evolutionary conservation in function, telomeric DNA is known to drastically vary in length and sequence between different eukaryotic lineages. Bryophytes are a group of early diverging land plants that include mosses, liverworts, and hornworts. This group of ancient land plants recently emerged as a new model for important discoveries in genomics and evolutionary biology, as well as for understanding plant adaptations to a terrestrial lifestyle. We measured telomere length in different ecotypes of model bryophyte species, including Physcomitrium patens, Marchantia polymorpha, Ceratodon purpureus, and in Sphagnum isolates. Our data indicate that all analyzed moss and liverwort genotypes have relatively short telomeres. Furthermore, all analyzed ecotypes and isolates of model mosses and liverworts display evidence of substantial natural variation in telomere length. Interestingly, telomere length also differs between male and female strains of the dioecious liverwort M. polymorpha and dioecious moss C. purpureus. Given that bryophytes are extraordinarily well adapted to different ecological niches from polar to tropical environments, our data will contribute to understanding the impact of natural telomere length variation on evolutionary adaptations in this ancient land plant lineage.

Strong intraspecific phylogenetic and karyotypic diversification in Isophya modestior (Orthoptera: Tettigoniidae: Phaneropterinae)

Isophya modestior (Orthoptera: Tettigoniidae) is a species distributed in central and south-eastern Europe, where its distribution is largely separated by two large rivers (Sava and Danube). Since previous studies on the song and morphology of the stridulatory file across its complete geographic range showed that the species is separated into two main groups, we decided to use phylogenetic and karyological analyses in order to evaluate the status of the previously analysed populations.

Phylogenetic analyses showed the existence of two major clades within I. modestior with very high bootstrap values and posterior probabilities—Clade A: present on the Balkan Peninsula, Slovenia (Inner Carniola), Italy, Pannonian Serbia (Vršac Mts and Deronje) and Austria (Burgenland and Lower Austria); Clade B: present in Slovenia (Upper Carniola), Croatia and Austria (Carinthia), Pannonian Serbia (Fruška Gora Mt.) and Hungary.

A comparison of chromosomes of 51 specimens revealed discrete differences between their karyotypes. The physical characteristics of the karyotypes included chromosome number (2n), sex chromosome (X) morphology and C-banding patterns. The standard chromosome complement of 50 specimens from different localities is characterized by 2n = 30 + X0 in males. In one male collected in Fruška Gora Mt. (Andrevlje), the chromosome number was reduced to 2n = 28 + neo-XY. Therefore, further cytogenetic studies involving larger samples, especially from Fruška Gora Mt., are needed in order to gain a more comprehensive view of the chromosome evolution in this group of Isophya species.