Table 1.
Summary of mammary gland phenotypes displayed by animals with different mutant hedgehog network genes. Blue background indicates loss-of-function or hypomorphic alleles; orange indicates overexpression and/or conditionally activated alleles. (Tx) in the first column signifies that mammary epithelium was transplanted due to embryonic lethality of mutant animals. ND = No data. All references listed in far right column. See Figure 3 for cartoon summary.
| Mutation | Epithelial Histological Phenotype |
Stromal Phenotype |
Lactation Phenotype |
Stunted Ductal Outgrowth |
Epithelial Proliferation |
Other | Ref |
|---|---|---|---|---|---|---|---|
| Shh-/- (Tx) | No | No | No | No | ND | 49 | |
| Wap-Shh | Yes | Yes | Yes | No | Reduced in dysplasias | Dilated ducts, expanded basal population, hyperplasia | 49 |
| Ihh-/- (Tx) | No | No | No | No | ND | 49 | |
| Ptch1mes/mes | Yes | ND | ND | Yes | Sometimes increased | Epithelial, stromal, and systemic functions of Ptch1 (undefined) | 53 |
| PtchlΔ/+ | Yes | Yes | ND | Yes | Sometimes increased | Strain dependent hyperproliferation | 51 |
| MMTV-SmoM2 | Yes | Yes | ND | No | Increased | Incr. branching, decr. stem cell frequency | 57 |
| Ad-Cre; SmoM2 | Yes | Yes | ND | No | Increased | Incr branching, altered cell fate | 58 |
| Gli1 laczki/ki | ND | ND | No | ND | ND | No overt lactation or embryonic defects | 59 |
| MMTV-rtTA; TRE-Gli1 | Yes | Yes | Yes | No | Increased | Tumorigenesis | 60, 86 |
| Gli2-/- (Tx) | Yes | Yes | No | No | ND | Ductal dilation, focal dysplasia | 61 |
| Gli3xt/xt | ND | ND | ND | ND | ND | Loss of embryonic buds 3 and 5 | 59, 68 |