The gene encoding protein 4.2 is distinct from the mouse platelet storage pool deficiency mutation pallid

Area of Science:

• Genetics
• Molecular Biology
• Hematology

Background:

• Previous studies suggested the erythrocyte membrane protein 4.2 (Epb4.2) gene was a candidate for the mouse pallid (pa) mutation.
• Epb4.2 genetically colocalized with pa on mouse Chromosome 2, and a truncated Epb4.2 transcript was found in pallid mouse tissues.

Purpose of the Study:

• To investigate the allelic relationship between the Epb4.2 gene and the mouse pallid (pa) mutation.
• To determine if the truncated Epb4.2 transcript in pallid mice is due to the pa mutation or a separate genetic factor.

Main Methods:

• Sequence analysis of pallid cDNA and intron/exon boundaries.
• Immunoblotting to detect protein 4.2 in pallid tissues.
• Genetic recombination analysis in F2 interspecific mice.
• Northern blotting of kidney mRNA from wild mice.

Main Results:

• No significant sequence variation in pallid Epb4.2 cDNA or intron/exon boundaries compared to wild-type.
• Normal 72-kDa protein 4.2 is present in pallid mouse tissues.
• Two recombinations between Epb4.2 and pa loci were observed in 173 F2 animals.
• A truncated Epb4.2 transcript, identical to that in pallid mice, was detected in normal wild Mus domesticus (WSB/Ei) mice.

Conclusions:

• The Epb4.2 gene and the pallid (pa) mutation are distinct loci.
• The truncated Epb4.2 mRNA found in pallid mice is a normal polymorphism inherited from its wild ancestor.
• Epb4.2 is not the gene responsible for the pallid mutation.