Chromosome Constitution (chromosome + constitution)

Distribution by Scientific Domains
Life Sciences100%

Selected Abstracts

The study of introgressive lines of Triticum aestivum × Aegilops speltoides by in situ and SSR analyses

PLANT BREEDING, Issue 3 2004
I. G. Adonina
Abstract Fluorescence in situ hybridization (FISH) with a genome-specific repeat, Spelt1, and wheat simple sequence repeat (SSR) markers were used to analyse the chromosome constitution of two Triticum aestivum×Aegilops speltoides introgressive lines. The lines 170/98i and 178/98i carried one and two subtelomeric regions of Ae. speltoides (per haploid genome), respectively, marked by Spelt1 repeats according to FISH data. SSR analysis detected homoeologous substitution of wheat chromosome 7D with Ae. speltoides chromosome 7S in the lines 178/98i and 170/98i as well as the assumed terminal translocation in the short arm of chromosome 3A in the line 178/98i. Anthocyanin pigmentation of the coleoptiles was found in the lines 170/98i and 178/98i and resulted from the 7S (7D) substitution. It was demonstrated that Spelt1 could be effectively used for the rapid identification (without DNA isolation) of terminal translocations of T. aestivum×Ae. speltoides introgressive lines as well as for further analysis of the stability of the hybrid plants. [source]

Prenatal diagnosis of female monozygotic twins discordant for Turner syndrome: implications for prenatal genetic counselling

PRENATAL DIAGNOSIS, Issue 8 2002
B. Gilbert
Abstract We describe a set of monozygotic (MZ) female twins, one of whom presented with a typical Turner syndrome (TS) phenotype and the other a normal female phenotype. Prenatal fetal ultrasonographic examination showed a monochorial diamniotic pregnancy with a hygroma colli and growth delay in Twin A and no anomalies in Twin B. Karyotypic analysis performed on fetal blood samples demonstrated a 46,XX/45,X (23/2) mosaicism in Twin A and a normal 46,XX chromosome constitution in Twin B. At birth, Twin A presented with a typical TS and Twin B had a normal female phenotype. Postnatal cytogenetic investigation of blood lymphocytes showed the same 46,XX/45,X mosaicism in both twins: 46,XX/45,X (40/7) in Twin A and 46,XX/45,X (40/5) in Twin B. Further investigations at the age of 10,months showed in Twin A a 46,XX/45,X (98/2) mosaicism in lymphocytes and 100% of 45,X (50 analysed cells) in fibroblasts, and in Twin B a normal 46,XX (100 analysed cells) chromosome constitution in lymphocytes but a mild 46,XX/45,X (78/2) mosaicism in fibroblasts. Monozygosity was confirmed by molecular analysis. To our knowledge, this is the first report of prenatal diagnosis of MZ female twins discordant for TS. Review of reported sets of MZ female twins (eight cases) or triplets (one case) discordant for TS shows, as in the present case, that the phenotype correlates better with the chromosomal distribution of mosaicism in fibroblasts than in lymphocytes. In the blood of MZ twins chimerism may modify the initial allocation of the mosaicism. These results suggest that, in cases of prenatal diagnosis of MZ female twins discordant for TS, the phenotype of each twin would be better predicted from karyotype analysis of cells from amniotic fluid than from fetal blood. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Molecular cytogenetic characterization of Thinopyrum genomes conferring perennial growth habit in wheat- Thinopyrum amphiploids

PLANT BREEDING, Issue 1 2001
X. Cai
Abstract Seven wheat- Thinopyrum amphiploids, AT 3425, AgCs, PI 550710, PI 550711, PI 550712, PI 550713 and PI 550714, were evaluated for perennial growth habit in the field. Three of them, AgCs, AT 3425, and PI 550713, were identified as perennials. Fluorescent genomic in situ hybridization (FGISH) patterns of mitotic chromosomes indicated that AgCs had seven pairs of Thinopyrum chromosomes and 21 pairs of wheat chromosomes. PI 550713 and AT 3425 showed similar FGISH patterns of mitotic chromosomes with three pairs of wheat- Thinopyrum translocated chromosomes, seven pairs of Thinopyrum chromosomes, and 18 pairs of wheat chromosomes. Thinopyrum chromosome pairing in the Fi hybrid of AT 3425 with AgCs demonstrated differences between Thinopyrum genomes in these two amphiploids. Based on chromosome constitutions, pairing and reported pedigrees, AgCs and AT 3425 were identified as a wheat- Thinopyrum elongatum amphiploid and partial wheat- Thinopyrum ponticum amphiploid, respectively. Chromosome pairing in the F1 hybrid between AT 3425 and PI 550713 revealed that these two amphiploids contained the same Thinopyrum genome. Two different Thinopyrum genomes conferring perennial growth habit were identified from the perennial amphiploids and characterized cytogenetically. [source]