Four natural populations of the grasshopper Eyprepocnemis plorans in the Mallorca island were analysed for several years revealing the recent invasion of the B1 chromosome from the south-west part of the island (Palma region) towards the north and to the east. In only 10 years, the mean number of Bs in the northern population at Pollença increased from 0.053 to 0.692. Therefore, B chromosome in...

a cytogenetical study on 13 alfalfa (medicago sativa) cultivars available in iranian forest and rangelands genebank was performed in order to obtain basic information on the variability in chiasma frequency/distribution, chromosome association and segregation. such cytogenetic information is useful for planning hybridization programs. cluster analysis of meiotic data and ordination of cultivars...

A cytogenetical study on 13 alfalfa (Medicago sativa) cultivars available in Iranian Forest and Rangelands Genebank was performed in order to obtain basic information on the variability in chiasma frequency/distribution, chromosome association and segregation. Such cytogenetic information is useful for planning hybridization programs. Cluster analysis of meiotic data and ordination of cultivars...

Chiasma counting has been regarded as the most straightforward method of scoring the total number of crossing-over events in the genome. In organisms in which genetic analysis is difficult or impossible to perform, it is a good estimator of the level of genetic recombination. In this paper we evaluated the chiasma frequency and distribution at diakinesis of twelve Brazilian oat varieties (Avena...

Two T7OH/+ translocation-carrying male mice were used in an investigation into the relation between the segregation pattern of the translocation caused multivalent at anaphase I and the position of the only chiasma in a long interstitial segment. Moreover, the relation between meiotic stage (from early diakinesis to metaphase I) and chiasma movement was assessed. It appeared that pronounced mov...

This study aims to determine the distribution of radiation doses on PTV and OAR radioteraphy planning in RSUP. Prof. Dr. I.G.N.G Ngoerah, Bali, Indonesia does no exceed a predetermined limit. The research metode used is value Homogenity Index (H), Conformity (CI), maximum ose Organ At Risk (OAR), amely right eye lens, left brainstem, optic chiasma, spinal cord. These data are compared with prov...

The study evaluated neuroophthalmologic and computerized tomography (CT) findings in 100 patients with somatotrophic adenoma and clinical picture of acromegaly, who underwent transsphenoidal adenomectomy. Prior to the surgery, visual field was normal in 77 patients. The diameter of adenoma in these patients ranged from 8 to 30 mm on CT, and the average value was 13.5 mm. Various kinds of visual...

Information concerning natural variation either in chiasma frequency or in the genetic basis of any such variation is a valuable tool to characterize phenotypic traits and their genetic control. Here meiotic recombination frequencies are analysed in nine geographically and ecologically diverse accessions of Arabidopsis thaliana, and a comparative study was carried out incorporating previous dat...

Ordered tetrad data yield information on chromatid interference, chiasma interference, and centromere locations. In this article, we show that the assumption of no chromatid interference imposes certain constraints on multilocus ordered tetrad probabilities. Assuming no chromatid interference, these constraints can be used to order markers under general chiasma processes. We also derive multilo...

The gross anatomy of the optic nerves and chiasma has been studied, and differences in the tension in the crossed and uncrossed fibres after chiasmal displacement have been investigated. The anterior and posterior attachments of the medial and lateral fibres of the nerves have been studied. The chiasma has been dissected under low power microscopy and a three dimensional picture of it developed...