Phenotypes Associated with This Genotype

Genotype
MGI:5432250

• Allelic Composition: Tg(MMTV-rtTA)1Lach/0; Tg(tetO-MYC)1Lach/0
• Genetic Background: involves: FVB

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

neoplasm

increased mammary gland tumor incidence ( J:67498 , J:133578 )

♀ • chronically doxycycline induced females develop mammary tumors with high penetrance (86%) following an average of 22 weeks of induction (J:67498)

♀ • mice fed doxycycline after weaning develop solitary mammary tumors with a median latency of 26 weeks after induction (J:133578)

increased mammary adenocarcinoma incidence ( J:67498 )

♀ • mammary tumors in chronically doxycycline induced females are invasive mammary adenocarcinomas

♀ • withdrawal of doxycycline from chronically induced tumor-bearing mutants results in rapid regression of a subset of invasive mammary adenocarcinomas (14 days) but another subset of tumors decrease in size but then resume growth

♀ • tumors that continue to grow after doxycycline removal show undetectable expression of the MYC transgene but increased endogenous Myc expression and exhibit mutations in Kras or Nras

integument

increased mammary gland epithelial cell proliferation ( J:67498 )

♀ • mammary epithelium of mutants induced with doxycycline exhibits increased proliferation

abnormal mammary gland morphology ( J:67498 )

♀ • mammary glands of mutants induced with doxycycline for 4 months exhibit atypical lobuloalveolar growths (dysplasia)

abnormal mammary gland epithelium morphology ( J:67498 )

♀ • non-tumor bearing mammary glands of mutants induced with doxycycline for 30 weeks (chronically induced) exhibit numerous epithelial hyperplasts and dysplasts, however when doxycycline is withdrawn for 12 weeks, most epithelial ducts appear normal

increased mammary gland tumor incidence ( J:67498 , J:133578 )

♀ • chronically doxycycline induced females develop mammary tumors with high penetrance (86%) following an average of 22 weeks of induction (J:67498)

♀ • mice fed doxycycline after weaning develop solitary mammary tumors with a median latency of 26 weeks after induction (J:133578)

increased mammary adenocarcinoma incidence ( J:67498 )

♀ • mammary tumors in chronically doxycycline induced females are invasive mammary adenocarcinomas

♀ • withdrawal of doxycycline from chronically induced tumor-bearing mutants results in rapid regression of a subset of invasive mammary adenocarcinomas (14 days) but another subset of tumors decrease in size but then resume growth

♀ • tumors that continue to grow after doxycycline removal show undetectable expression of the MYC transgene but increased endogenous Myc expression and exhibit mutations in Kras or Nras

mammary gland hyperplasia ( J:67498 )

♀ • mammary glands of mutants induced with doxycycline for 30 days are hyperplastic

♀ • mammary glands of mutants induced with doxycycline for 4 months exhibit focal hyperplasia

increased mammary gland apoptosis ( J:67498 )

♀ • mammary epithelium of mutants induced with doxycycline exhibits increased apoptosis

endocrine/exocrine glands

increased mammary gland epithelial cell proliferation ( J:67498 )

♀ • mammary epithelium of mutants induced with doxycycline exhibits increased proliferation

abnormal mammary gland morphology ( J:67498 )

♀ • mammary glands of mutants induced with doxycycline for 4 months exhibit atypical lobuloalveolar growths (dysplasia)

abnormal mammary gland epithelium morphology ( J:67498 )

♀ • non-tumor bearing mammary glands of mutants induced with doxycycline for 30 weeks (chronically induced) exhibit numerous epithelial hyperplasts and dysplasts, however when doxycycline is withdrawn for 12 weeks, most epithelial ducts appear normal

increased mammary gland tumor incidence ( J:67498 , J:133578 )

♀ • chronically doxycycline induced females develop mammary tumors with high penetrance (86%) following an average of 22 weeks of induction (J:67498)

♀ • mice fed doxycycline after weaning develop solitary mammary tumors with a median latency of 26 weeks after induction (J:133578)

increased mammary adenocarcinoma incidence ( J:67498 )

♀ • mammary tumors in chronically doxycycline induced females are invasive mammary adenocarcinomas

♀ • withdrawal of doxycycline from chronically induced tumor-bearing mutants results in rapid regression of a subset of invasive mammary adenocarcinomas (14 days) but another subset of tumors decrease in size but then resume growth

♀ • tumors that continue to grow after doxycycline removal show undetectable expression of the MYC transgene but increased endogenous Myc expression and exhibit mutations in Kras or Nras

mammary gland hyperplasia ( J:67498 )

♀ • mammary glands of mutants induced with doxycycline for 30 days are hyperplastic

♀ • mammary glands of mutants induced with doxycycline for 4 months exhibit focal hyperplasia

increased mammary gland apoptosis ( J:67498 )

♀ • mammary epithelium of mutants induced with doxycycline exhibits increased apoptosis

cellular

increased mammary gland epithelial cell proliferation ( J:67498 )

♀ • mammary epithelium of mutants induced with doxycycline exhibits increased proliferation

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
breast cancer		DOID:1612	OMIM:114480	J:67498 , J:133578