Eleven populations of five Avena species were analysed for meiotic characters including chiasma frequency and distribution as well as chromosomal association and segregation. Plants of a single population of A. eriantha showed the presence of 2n = 14 (diploid) and 2n = 4x = 28 chromosome number. Populations of A. barbata and A. wiestii possessed n = 14, while populations of A. sterilis ssp. lud...

Pseudacteon flies, parasitoids of worker ants, are being intensively studied as potentially effective agents in the biological control of the invasive pest fire ant genus Solenopsis (Hymenoptera: Formicidae). This is the first attempt to describe the karyotype of P. curvatus Borgmeier, P. nocens Borgmeier and P. tricuspis Borgmeier. The three species possess 2n = 6; chromosomes I and II were me...

Chromosomal patterns of experimental animals are useful tools for cytogenetics research and animal breeding. Chromosome investigations of the hairless guinea pig are rare, therefore, karyotype of hairless guinea pigs (twelve male and female) was studied using metaphase spreads of bone marrows and G banding techniques. The chromosomes diploid number was 2n= 64 and polymorphism of three type chro...

Cytogenetic studies on 64 rat leukemias induced with 7,8,12- and 6,8,12-trimethylbenz(a)anthracene were performed. Highly distinctive changes were found repeatedly in one special pair of chromosomes. 10 leukemias (15.6%) showed the presence of stemline(s) with trisomy of the largest telocentric chromosome (C-1 trisomy). Another chromosome abnormality, elongation of one of the pairs of the same ...

genus onobrychis comprised of many cultivated as well as wild species is adapted to different regions of iran. this study was conducted to evaluate the karyotype characteristics of seven onobrychis species, employing the analysis of metaphase chromosomes of mitotic cells. results revealed that the species o. melanotricha (from semirom and feriedan)‚ o. sativa (from arak and boroujen) with 2n=28...

Recent phylogenetic and molecular data are changing our knowledge about the relations between species evolutionary processes resulting in chromosome variation observed ants (Hymenoptera: Formicidae). Ants exhibit remarkable variations morphology, behavior, karyotypes, structure. By assembling genetic information trap-jaw from subfamily Ponerinae, we reconstructed relationships that inferred mon...

Recent advances in human cytogenetics have provided impetus for the mapping of autosomal genes. Inherited variations in the morphology of the chromosomes, such as translocations and deletions, can be used as markers in identifying chromosomes and possibly in localizing the genes within such chromosomes. Penrose and Delhanty (1961) and Shaw (1962) described two different pedigrees in which a 15/...