X-linked gene expression in the Virginia opossum: differences between the paternally derived Gpd and Pgk-A loci
Expression of X-linked glucose-6-phosphate dehydrogenase (G6PD) and phosphoglycerate kinase-A (PGK-A) in the Virginia opossum (Didelphis virginiana) was studied electrophoretically in animals from natural populations and those produced through controlled laboratory crosses. Blood from most of the wild animals exhibited a common single-banded phenotype for both enzymes. Rare variant animals, regardless of sex, exhibited single-banded phenotypes different in mobility from the common mobility class of the respective enzyme. The laboratory crosses confirmed the allelic basis for the common and rare phenotypes. Transmission of PGK-A phenotypes followed the pattern of determinate (nonrandom) inactivation of the paternally derived Pgk-A allele, and transmission of G6PD also was consistent with this pattern. A survey of tissue-specific expression of G6PD phenotypes of heterozygous females revealed, in almost all tissues, three-banded patterns skewed in favor of the allele that was expressed in blood cells. Three-banded patterns were never observed in males or in putatively homozygous females. These patterns suggest simultaneous, but unequal, expression of the maternally and paternally derived Gpd alleles within individual cells. The absence of such partial expression was noted in a parallel survey of females heterozygous at the Pgd-A locus. Thus, it appears that Gpd and Pgk-A are X-linked in D. virginiana and subject to preferential paternal allele inactivation, but that dosage compensation may not be complete for all paternally derived X-linked genes.
- Research Organization:
- Southwest Foundation for Biomedical Research, San Antonio, TX
- OSTI ID:
- 6869810
- Journal Information:
- Genetics; (United States), Vol. 115:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
MARSUPIALS
GENE REGULATION
OXIDOREDUCTASES
ELECTROPHORESIS
PHOSPHOTRANSFERASES
BLOOD
GENES
GENETIC VARIABILITY
PHENOTYPE
X CHROMOSOME
ANIMALS
BIOLOGICAL MATERIALS
BIOLOGICAL VARIABILITY
BODY FLUIDS
CHROMOSOMES
ENZYMES
HETEROCHROMOSOMES
MAMMALS
MATERIALS
PHOSPHORUS-GROUP TRANSFERASES
TRANSFERASES
VERTEBRATES
550400* - Genetics