14 research outputs found
Cohesion proteins are present in centromere protein bodies associated with avian lampbrush chromosomes
Centromere positions in chicken and Japanese quail chromosomes: de novo centromere formation versus pericentric inversions
Organization of the Epidermal Syncytial Mosaic in Diceratocephala-Boschmai (Temnocephalida, Platyhelminthes)
Avian sex chromosomes in the lampbrush form: the ZW lampbrush bivalents from six species of bird
Impact of Training and Municipal Support on Primary Health Care–Based Measurement of Alcohol Consumption in Three Latin American Countries: 5-Month Outcome Results of the Quasi-experimental Randomized SCALA Trial
Implementing primary healthcare-based measurement, advice and treatment for heavy drinking and comorbid depression at the municipal level in three Latin American countries: final protocol for a quasiexperimental study (SCALA study)
Low-voltage scanning electron microscopy study of lampbrush chromosomes and nuclear bodies in avian and amphibian oocytes
Higher-order genome organization in platypus and chicken sperm and repositioning of sex chromosomes during mammalian evolution
In mammals, chromosomes occupy defined positions in sperm, whereas previous work in chicken showed random chromosome distribution. Monotremes (platypus and echidnas) are the most basal group of living mammals. They have elongated sperm like chicken and a complex sex chromosome system with homology to chicken sex chromosomes. We used platypus and chicken genomic clones to investigate genome organization in sperm. In chicken sperm, about half of the chromosomes investigated are organized non-randomly, whereas in platypus chromosome organization in sperm is almost entirely non-random. The use of genomic clones allowed us to determine chromosome orientation and chromatin compaction in sperm. We found that in both species chromosomes maintain orientation of chromosomes in sperm independent of random or non-random positioning along the sperm nucleus. The distance of loci correlated with the total length of sperm nuclei, suggesting that chromatin extension depends on sperm elongation. In platypus, most sex chromosomes cluster in the posterior region of the sperm nucleus, presumably the result of postmeiotic association of sex chromosomes. Chicken and platypus autosomes sharing homology with the human X chromosome located centrally in both species suggesting that this is the ancestral position. This suggests that in some therian mammals a more anterior position of the X chromosome has evolved independently.Enkhjargal Tsend-Ayush, Natasha Dodge, Julia Mohr, Aaron Casey, Heinz Himmelbauer, Colin L. Kremitzki, Kyriena Schatzkamer, Tina Graves, Wesley C. Warren and Frank GrĂĽtzne