Production of lampbrush chromosome

A method analyzing chromosomes for abnormalities, comprising:

• contacting inactive chromosomes with the contents of germinal vesicles of an oocyte;
• incubating the inactive chromosomes and germinal vesicle contents for a period of time sufficient to produce transcriptionally active, individually recognizable lampbrush chromosomes;
• and
• subjecting the transcriptionally active individually recognizable lampbrush chromosomes to cytogenetic analysis.

A method for producing a transcriptionally active lampbrush chromosome, comprising:

• (a) providing at least one chromosome obtained from a species;
• (b) contacting said chromosome with an amount of germinal vesicle contents of at least one oocyte, wherein said oocyte is from a different species than said species from which the chromosome is obtained;
• and
• (c) incubating said chromosome with said amount of germinal vesicle contents for a time period, wherein said amount is effective to and said time period is sufficient to produce at least one transcriptionally active lampbrush chromosome.

A method for producing a chromosome with transcriptionally-active regions that loop laterally from its main axis, comprising:

• (a) providing at least one chromosome obtained from condensed chromatin of a species;
• (b) contacting said chromosome with an amount of germinal vesicle contents of at least one oocyte, wherein said oocyte is from a different species than said species from which the chromosome is obtained;
• and
• (c) incubating said chromosome with said amount of germinal vesicle contents for a time period, wherein said amount is effective to and said time period is sufficient to produce at least one chromosome with transcriptionally-active regions that loop laterally from its main axis.