Low H-2 polymorphism in some Israeli wild mouse populations

Area of Science:

• Immunogenetics
• Population Genetics
• Mammalian Genetics

Background:

• The Major Histocompatibility Complex (MHC) in mice, known as the H-2 complex, plays a crucial role in immune responses and is highly polymorphic.
• Understanding H-2 polymorphism in wild populations is essential for insights into immune system evolution and adaptation.
• Previous studies have characterized H-2 diversity in various mouse populations, but comprehensive analysis in mainland populations near Jerusalem was lacking.

Purpose of the Study:

• To investigate and characterize the H-2 polymorphism in two distinct wild house mouse (Mus domesticus) populations near Jerusalem.
• To identify novel H-2 haplotypes within these wild populations.
• To determine the distribution and frequency of H-2 alleles and haplotypes in the studied populations and surrounding areas.

Main Methods:

• Generation of 27 H-2 homozygous lines by cross-breeding wild mice with laboratory strains.
• Serological typing of H-2 homozygous lines using monoclonal and polyclonal antibodies against H-2K, H-2D, H-2A, and H-2E loci.
• Identification of new H-2 haplotypes and characterization of allele frequencies in wild populations using newly developed antisera.

Main Results:

• Identification of four new H-2 haplotypes: H-2w82, H-2w83, H-2w84, and a recombinant H-2w85.
• Wild populations exhibited three alleles at the H-2K locus (Kw16, Kw83, Kw84) and three at the H-2D locus (Dw16, Dw82, Dw84).
• Allele frequencies ranged from 0.12-0.54, with no significant differences between the two studied populations and a significant excess of heterozygotes.

Conclusions:

• The H-2 polymorphism in the studied wild house mouse populations is comparable to that observed in many non-H-2 loci.
• The identified H-2 haplotypes appear to be stable within the East Talpiot populations, with evidence of heterozygote advantage.
• The H-2 haplotype diversity in the Jerusalem area is limited, with three main haplotypes dominating the regional populations.