Chromosome painting in marsupials: genome conservation in the kangaroo family.
In order to deduce the ancestral genome arrangement in the karyotypically diverse marsupial family Macropodidae, and to assess chromosome change in this family, chromosome-specific paints from the tammar wallaby (2n = 16) were hybridized to metaphase spreads from the two species proposed to represent the 2n = 22 ancestral karyotype, as well as species with derived 2n = 20 and 2n = 14 karyotypes. Identical patterns were observed in the two 2n = 22 species, from which the rearrangements to form the three derived karyotypes may be easily deduced to be 1, 3 and 4 different fusions, respectively. The identical Thylogale and Dorcopsis genomes may both be used to represent the pleisiomorphic macropodid chromosome complement. Variation in the X chromosome was also investigated by hybridizing an X-Y shared tammar wallaby 12-kb repeat element to chromosomes from the other four macropodid species, finding that it hybridized only to the most closely related species, and therefore is of recent origin.
Department of Genetics and Human Variation, La Trobe University, Bundoora, VIC, Australia.
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Glas
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De Leo
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Delbridge
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Reid
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Ferguson-Smith
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O'Brien
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Westerman
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Graves
D000818:Animals; D020223:Chromosome Painting; D005260:Female; D007621:Karyotyping; D007614:Macropodidae / Q000145:classification / Q000235:genetics*; D008297:Male; D010802:Phylogeny