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Insulin is imprinted in the placenta of the marsupial, Macropus eugenii
- Source :
- Developmental Biology. 309:317-328
- Publication Year :
- 2007
- Publisher :
- Elsevier BV, 2007.
-
Abstract
- Therian mammals (marsupials and eutherians) rely on a placenta for embryo survival. All mammals have a yolk sac, but while both chorio-allantoic and chorio-vitelline (yolk sac) placentation can occur, most marsupials only develop a yolk sac placenta. Insulin (INS) is unusual in that it is the only gene that is imprinted exclusively in the yolk sac placenta. Marsupials, therefore, provide a unique opportunity to examine the conservation of INS imprinting in mammalian yolk sac placentation. Marsupial INS was cloned and its imprint status in the yolk sac placenta of the tammar wallaby, Macropus eugenii, examined. In two informative individuals of the eight that showed imprinting, INS was paternally expressed. INS protein was restricted to the yolk sac endoderm, while insulin receptor, IR, protein was additionally expressed in the trophoblast. INS protein increased during late gestation up to 2 days before birth, but was low the day before and on the day of birth. The conservation of imprinted expression of insulin in the yolk sac placenta of divergent mammalian species suggests that it is of critical importance in the yolk sac placenta. The restriction of imprinting to the yolk sac suggests that imprinting of INS evolved in the chorio-vitelline placenta independently of other tissues in the therian ancestor of marsupials and eutherians.
- Subjects :
- INS
medicine.medical_specialty
Genomic imprinting
Evolution
Placenta
Molecular Sequence Data
Andrology
Tammar wallaby
Pregnancy
Internal medicine
medicine
Animals
Insulin
Amino Acid Sequence
Chorio-vitelline placenta
Yolk sac
Imprinting (psychology)
Molecular Biology
reproductive and urinary physiology
Marsupial
Polymorphism, Genetic
Base Sequence
biology
Placentation
Trophoblast
Embryo
Cell Biology
biology.organism_classification
Marsupialia
medicine.anatomical_structure
Endocrinology
embryonic structures
Female
Developmental Biology
Subjects
Details
- ISSN :
- 00121606
- Volume :
- 309
- Database :
- OpenAIRE
- Journal :
- Developmental Biology
- Accession number :
- edsair.doi.dedup.....31acf228dd77db729622fd7074540b77