Biomaterial Database

Chromosome banding in amphibia. XX. DNA replication patterns in Gastrotheca riobambae (Anura, Hylidae). 1994

M Schmid, and R Klett

Department of Human Genetics, University of Würzburg, FRG.

Replication banding patterns were induced in the chromosomes of Gastrotheca riobambae by treating cell cultures with 5-bromodeoxyuridine (BrdU) and deoxythymidine (dT). In particular, the time sequence of replication of the highly differentiated XY/XX sex chromosomes was meticulously analyzed throughout the S phase. In the homogametic female, BrdU/dT labeling revealed no evidence of asynchronous replication between euchromatic regions in the XX pair. Minor replication asynchronies between the two X chromosomes were restricted to the heterochromatic C-bands. These results are further proof that dosage compensation in Amphibia for X- or Z-linked genes does not occur by inactivation of one of the two (XX or ZZ) sex chromosomes in the cells of homogametic individuals. In the very large and almost completely heterochromatic Y chromosome of G. riobambae, the various C-bands comprise at least three different structural categories, resulting in a complex pattern of early- and late-replicating bands along the Y chromosome.

UI	MeSH Term	Description	Entries
D007621	Karyotyping	Mapping of the KARYOTYPE of a cell.	Karyotype Analysis Methods,Analysis Method, Karyotype,Analysis Methods, Karyotype,Karyotype Analysis Method,Karyotypings,Method, Karyotype Analysis,Methods, Karyotype Analysis
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D002871	Chromosome Banding	Staining of bands, or chromosome segments, allowing the precise identification of individual chromosomes or parts of chromosomes. Applications include the determination of chromosome rearrangements in malformation syndromes and cancer, the chemistry of chromosome segments, chromosome changes during evolution, and, in conjunction with cell hybridization studies, chromosome mapping.	Banding, Chromosome,Bandings, Chromosome,Chromosome Bandings
D004261	DNA Replication	The process by which a DNA molecule is duplicated.	Autonomous Replication,Replication, Autonomous,Autonomous Replications,DNA Replications,Replication, DNA,Replications, Autonomous,Replications, DNA
D005260	Female		Females
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001001	Anura	An order of the class Amphibia, which includes several families of frogs and toads. They are characterized by well developed hind limbs adapted for jumping, fused head and trunk and webbed toes. The term "toad" is ambiguous and is properly applied only to the family Bufonidae.	Bombina,Frogs and Toads,Salientia,Toad, Fire-Bellied,Toads and Frogs,Anuras,Fire-Bellied Toad,Fire-Bellied Toads,Salientias,Toad, Fire Bellied,Toads, Fire-Bellied
D012730	Sex Chromosomes	The homologous chromosomes that are dissimilar in the heterogametic sex. There are the X CHROMOSOME, the Y CHROMOSOME, and the W, Z chromosomes (in animals in which the female is the heterogametic sex (the silkworm moth Bombyx mori, for example)). In such cases the W chromosome is the female-determining and the male is ZZ. (From King & Stansfield, A Dictionary of Genetics, 4th ed)	Gonosomes,Chromosome, Sex,Chromosomes, Sex,Gonosome,Sex Chromosome