The mouse prolactin gene family locus

Area of Science:

• Genomics
• Mammalian genetics
• Gene family evolution

Background:

• The mouse prolactin (PRL) gene family is large and comprises paralogous genes.
• Understanding the organization of this gene family locus is crucial for studying its function and evolution.

Purpose of the Study:

• To investigate the organization of the mouse PRL gene family locus.
• To identify new members of the mouse PRL gene family and characterize their expression patterns.

Main Methods:

• Localization of PRL gene family members using overlapping bacterial artificial chromosome clones.
• Arrangement of genes based on structural relationships.
• Identification of new gene members and analysis of their predicted amino acid sequences.
• Analysis of gene expression in mouse placenta trophoblast cells.

Main Results:

• The mouse PRL gene family locus was elucidated, revealing its organization on chromosome 13.
• Three contiguous genes encoding placental lactogen I (PL-I) were identified (PL-Ialpha, PL-Ibeta, PL-Igamma).
• Nine new PRL gene family members were discovered, including orthologs of rat PRL family members (PLP-I, PLP-K), new PLP-C subfamily members (PLP-Cgamma, PLP-Cdelta), and unique members (PLP-N, PLP-O).
• All nine newly discovered genes are expressed in mouse placenta trophoblast cells in a gestationally specific manner.

Conclusions:

• Elucidation of the mouse PRL gene family locus provides new insights into its expansion.
• The identified genes offer new tools for studying the genetics and biology of the mouse PRL family members.
• The discovery highlights the complexity and dynamic evolution of the PRL gene family in mice.