Karyotypic evolution in family Hipposideridae (Chiroptera, Mammalia) revealed by comparative chromosome painting, G- and C-banding

Comparing to its sister-family （Rhinolophidae）, Hipposideridae was less studied by cytogenetic approaches. Only a few high-resolution G-banded karyotypes have been reported so far, and most of the conclusions on the karyotypic evolution in Hipposideridae were based on conventional Giemsa-staining. In this study, we applied comparative chromosome painting, a method of choice for genome-wide comparison at the molecular level, and G- and C-banding to establish comparative map between five hipposiderid species from China, using a whole set of chromosome-specific painting probes from one of them （Aselliscus stoliczkanus）. G-band and C-band comparisons between homologous segments defined by chromosome painting revealed that Robertsonian translocations, paracentric inversions and heterochromatin addition could be the main mechanism of chromosome evolution in Hipposideridae. Comparative analysis of the conserved chromosomal segments among five hipposiderid species and outgroup species suggests that bi-armed chromosomes should be included into the ancestral karyotype of Hipposideridae, which was previously believed to be exclusively composed of acrocentric chromosomes.

Characterization of Two Human Lung Adenocarcinoma Cell Lines by Reciprocal Chromosome Painting

Lung cancer is a leading cause of cancer death worldwide. Some lung cancer patients correlate with a gas of radon besides smoking. To search for common chromosomal aberrations in lung cancer cell lines established from patients induced by different factors, a combined approach of chromosome sorting, forward and reverse chromosome painting was used to characterize karyotypes of two lung adenocarcinoma cell lines： A549 and GLC-82 with the latter line derived from a patient who has suffered long-term exposure to environmental radon gas pollution. The chromosome painting results revealed that complex chromosomal rearrangements occurred in these two lung adenocarcinoma cell lines. Thirteen and twenty-four abnormal chromosomes were identified An A549 and GLC-82 cell lines, respectively. Almost half of abnormal chromosomes in these two cell lines were formed by non-reciprocal translocations, the others were derived from deletions and duplication/or amplification in some chromosomal regions. Furthermore, two apparently common breakpoints, HSA8q24 and 12q14 were found in these two lung cancer cell lines.

Intergeneric chromosome-specific painting reveals differential chromosomal transmission from Tripidium arundinaceum in sugarcane progeny

Sugarcane has recently attracted increasing attention for its potential as a source of sugar and bioethanol,so increasing its yield is essential to ensure the sugar security and bioenergy production.Intergeneric hybridization is a highly efficient method to produce new genetic variants of crop plants,particularly those species with high ploidy such as sugarcane(Saccharum spp.).Tripidium arundinaceum exhibits many desirable agronomic traits,and has been widely studied to produce hybrids with improved stress tolerance and other characteristics in sugarcane breeding.However,the genetic relationship between T.arundinaceum and Saccharum species,and the individual T.arundinaceum chromosomal compositions in sugarcane hybrids are still elusive.Here we used whole-genome single-nucleotide polymorphisms(SNPs)to ascertain the phylogenetic relationships between these species and found that T.arundinaceum is more closely related to Saccharum than Sorghum,in contrast to the previous narrow genetic analyses using chloroplast DNA.Additionally,oligonucleotide(oligo)-based chromosome-specific painting derived from Saccharum officinarum was able to distinctly identify the chromosomes of T.arundinaceum.We developed the oligo-genomic in situ hybridization(GISH)system for the first time,to unveil the novel chromosome translocations and the transmission of individual T.arundinaceum chromosomes in sugarcane progeny.Notably,we discovered that the chromosomal transmission of T.arundinaceum exhibited several different inheritance modes,including n,2n,and over 2n in the BC1 progenies.Such inheritance patterns may have resulted from first division restitution(FDR)or FDR+nondisjunction of a chromosome with the sister chromatids in the second meiosis division/second division restitution(FDR+NSC/SDR)model during meiosis.These results will be of substantial benefit for the further selection of T.arundinaceum chromosomes for sugarcane genetic improvement.