Abstract A karyotypic study was performed on 12 Iranian local onion (Allium cepa L.) populations. A number of mitotic cells at metaphase stage for each population were prepared. Chromosomes of suitable mitotic cells were counted and various parameters, including long arm (L), short arm (S), total length of chromosome (TL), relative length of chromosome (RL), arm ratio (AR), r-value, total chro...

Sequencing of cereal genomes is not a feasible task due to their large size and high content of repetitive DNA sequences. There are two basic approaches to simplify analysis of such genomes: reduced representation approaches, such as EST sequencing, methyl filtration and Cot-based cloning and sequencing; on the other side there is analysis of genomes in a step-wise manner, e.g. through creation...

Background and Aims: Azoospermia factor (AZF) region of the Y-chromosome has several genes which are responsible for normal spermatogenesis. Microdeletions of these genes are associated with azoospermia and oligospermia. These microdeletions are too small to be detected by karyotyping. They can be easily identified using polymerase chain reaction. The aim of this study is to determine the frequ...

Rheum palmatum, one of the source plants of the traditional Chinese medicine rhubarb, is anendemic and endangered species. To our knowledge, this is the first report on the chromosome number and karyotype of this species. Sectioning combined with micrography was used to analyze the karyotype. The following results were obtained: R. palmatum had a stable chromosome number 2n = 22; the basic numb...

Chromosome numbers and other karyological data of four Stemona spp. (Stemonaceae) from Thailand are reported. Three taxa (S. collinsae Craib, S. kerrii Craib and an unidentified species) exhibit 2n = 14 chromosomes, for S. curtisii Hook.f. a range of 2n = 13–16 was established. Based on the counts of c. 30% of the species of Stemona, x = 7 is very likely to be the basic number for the genus. Ch...

An understanding of the basic defect in the inherited disorder cystic fibrosis requires cloning of the cystic fibrosis gene and definition of its protein product. In the absence of direct functional information, chromosomal map position is a guide for locating the gene. Chromosome walking and jumping and complementary DNA hybridization were used to isolate DNA sequences, encompassing more than ...

background: in most mammals, sex is determined at the beginning of gestation by the constitution of the sex chromosomes, xy in males and xx in females. case: here we report an interesting case characterized by ambiguous genitalia and ovotestis in a newborn carrying an apparently female karyotype (46 xx). array comparative genomic hybridization (array-cgh) revealed an unbalanced rearrangement re...

the genus onobrychis belongs to family fabaceae and has about 130 species throughout the world. onobrychis sect. hymenobrychis with nearly 14 species in iran is one of the important sections of the genus. the chromosome number and meiotic behaviour were studied in two populations of onobrychis chorassanica belonging to this section native to iran. this report is the first cytogenetic analysis o...