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.
Glas
R
R
Department of Genetics and Human Variation, La Trobe University, Bundoora, VIC, Australia.
De Leo
A A
AA
Delbridge
M L
ML
Reid
K
K
Ferguson-Smith
M A
MA
O'Brien
P C
PC
Westerman
M
M
Graves
J A
JA
D000818:Animals; D020223:Chromosome Painting; D005260:Female; D007621:Karyotyping; D007614:Macropodidae / Q000145:classification / Q000235:genetics*; D008297:Male; D010802:Phylogeny