The X chromosome of monotremes shares a highly conserved region with the eutherian and marsupial X chromosomes despite the absence of X chromosome inactivation

Journal Article · Sat Sep 01 00:00:00 EDT 1990 · Proceedings of the National Academy of Sciences of the United States of America; (United States)

DOI:https://doi.org/10.1073/pnas.87.18.7125· OSTI ID:5381633

Watson, J M; Spencer, J A; Graves, J A.M. ^[1]; Riggs, A D ^[2]

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1. La Trobe Univ., Bundoora, Victoria (Australia)
2. Beckman Inst., Duarte, CA (USA)

Eight genes, located on the long arm of the human X chromosome and present on the marsupial X chromosome, were mapped by in situ hybridization to the chromosomes of the platypus Ornithorhynchus anatinus, one of the three species of monotreme mammals. All were located on the X chromosome. The authors conclude that the long arm of the human X chromosome represents a highly conserved region that formed part of the X chromosome in a mammalian ancestor at least 150 million years ago. Since three of these genes are located on the long arm of the platypus X chromosome, which is G-band homologous to the Y chromosome and apparently exempt from X chromosome inactivation, the conservation of this region has evidently not depended on isolation by X-Y chromosome differentiation and X chromosome inactivation.

• OSTI ID: 5381633
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (United States), Vol. 87:18; ISSN 0027-8424
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
HUMAN X CHROMOSOME
BIOLOGICAL EVOLUTION
X CHROMOSOME
INACTIVATION
GENES
GENETIC MAPPING
MAN
MARSUPIALS
NUCLEOTIDES
TRITIUM COMPOUNDS
Y CHROMOSOME
ANIMALS
CHROMOSOMES
HETEROCHROMOSOMES
HYDROGEN COMPOUNDS
MAMMALS
MAPPING
ORGANIC COMPOUNDS
PRIMATES
VERTEBRATES
550401* - Genetics- Tracer Techniques