• Prolactin (PRL) is a polypeptide hormone primarily synthesized by lactotroph cells within the adenohypophysis (anterior pituitary gland). Notably, PRL is also produced in extrapituitary tissues, including the prostate and mammary glands, where it not only promotes glandular development but also exhibits pathophysiological relevance. Autocrine/paracrine PRL signaling in these peripheral tissues may contribute to oncogenesis, particularly in hormone-responsive carcinomas such as breast and prostate cancers.
• Gene targeting strategy for B-hPRL mice. The exons 2-5 of mouse Prl gene that encode the whole molecule (ATG to STOP codon), including 3’UTR were replaced by human counterparts in B-hPRL mice. The promoter and 5’UTR region of the mouse gene were retained. The human PRL expression was driven by endogenous mouse Prl promoter, while mouse Prl gene transcription and translation will be disrupted.
• Protein expression analysis: Human PRL was exclusively detectable in homozygous B-hPRL mice (H/H) but not in wild-type mice.

Gene targeting strategy for B-hPRL mice. The exons 2-5 of mouse Prl gene that encode the whole molecule, including 3’UTR were replaced by human counterparts in B-hPRL mice. The promoter and 5’UTR region of the mouse gene are retained. The human PRL expression was driven by endogenous mouse Prl promoter, while mouse Prl gene transcription and translation will be disrupted.

Strain specific PRL expression analysis in wild-type C57BL/6JNifdc mice and homozygous humanized B-hPRL mice by ELISA. Plasma was collected from wild-type C57BL/6JNifdc mice (+/+) (female, n=3, 8-week-old) and homozygous B-hPRL mice (H/H) (female, n=3, 8-week-old). Expression level of human PRL were analyzed by ELISA (Human Prolactin ELISA Kit, Abcam, ab226901). Human PRL was exclusively detectable in homozygous B-hPRL mice. Values are expressed as mean ± SEM.