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Deoxyribonucleic acid synthesis-dependent casein gene expression: species differences.
Endocrinology
|March 1, 1983
Summary
Mammary gland explants from mice, rats, and rabbits show increased DNA and casein synthesis with specific hormones. However, inhibiting DNA synthesis blocks casein production only in mice, indicating species-specific hormonal regulation.
Area of Science:
- Endocrinology
- Molecular Biology
- Developmental Biology
Background:
- Mammary gland development and differentiation are complex processes regulated by hormones.
- Hormonal regulation of casein synthesis, a key marker of mammary differentiation, varies across species.
Purpose of the Study:
- To investigate the role of DNA synthesis in hormone-induced casein production in mammary explants.
- To explore species-specific differences in mammary gland hormonal responses between mice, rats, and rabbits.
Main Methods:
- Organ culture of mammary gland explants from mature virgin mice, rats, and rabbits.
- Treatment with insulin, hydrocortisone, and prolactin (PRL).
- Inhibition of DNA synthesis using cytosine arabinoside and assessment of casein and RNA synthesis.
Main Results:
- Insulin, hydrocortisone, and PRL stimulated DNA and casein synthesis in explants from all three species.
- Cytosine arabinoside inhibited casein synthesis and casein mRNA accumulation in mouse explants but not in rat or rabbit explants.
- Hormone-induced increases in NADH-cytochrome c-reductase and total RNA synthesis were unaffected by cytosine arabinoside in mouse explants.
Conclusions:
- DNA synthesis is essential for stimulated casein synthesis in mature virgin mouse mammary explants, but not in rats or rabbits.
- The inhibitory effect of cytosine arabinoside on casein synthesis is at the level of casein mRNA accumulation.
- These findings highlight species-specific variations in the coupling of DNA synthesis and differentiation during mammary gland hormonal regulation.