The alymphoplasia (aly) mutation co-segregates with the intercellular adhesion molecule-2 (lcam-2) on mouse chromosome 11

A new spontaneous autosomal recessive mutation alymphoplasia (aly), which causes a systemic defect of lymph nodes and Peyer's patches, was mapped on mouse chromosome 11 by linkage analysis using (ALY x MSM)F1 x ALY backcross progeny (155 mice). The gene order and map distances on the chromosome were as follows (cM +/- SD); D11Mit14 (AntP91a), Krt-1 -(0.7 +/- 0.6)--D11Mit59--(1.9 +/- 1.1)--D11Mit52, D11Nds7 (Gfap)--(0.7 +/- 0.6)--aly, D11Mit10, D11Mit13 (Ace), D11Mit58 (Myla), lcam-2--(8.4 +/- 2.2)--D11Mit12. No recombinant was found among aly, D11Mit10, D11Mit13, D11Mit58 and lcam-2, suggesting the possible involvement of lcam-2 in the aly mutation. However, the nucleotide sequence of the lcam-2 gene of aly/aly mouse was identical to that of the control mouse. No difference was detected between aly/aly and the control mouse for expression of the gene by both Northern blot and reverse transcriptase polymerase chain reaction analyses. Furthermore, immunohistochemical analysis using a mAb revealed that the ICAM-2 protein was normally distributed in various tissues. These findings indicate that aly/aly mice do not suffer from defects of lcam-2. The four polymorphic microsatellite markers tightly linked with the aly gene will serve as admirable guideposts for a chromosomal walk to the aly gene.