The lymphopenia gene region and the Ian5transcript. (A) Physical map of the rat lyp gene region with genetic markers integrated (top). Overlapping PAC clones are shown along with the locations of genetic markers used to narrow the lyp interval, clone-end STS assays, and the limits of the lyp interval itself as a red arrow at both topand bottom. Distances between markers may not be strictly to scale because they are estimated on STS content. The bottompart shows an expanded view of the lyp interval, showing the locations of known genes and the extent of the assembled sequence contigs of rat genomic DNA, along with the framework of mouse genomic DNA sequence. A 13-kb-long rat genomic sequence contig includes the ratIan5 gene. Position coordinates shown are those from mouse sequence supercontig Mm6_WIFeb01_100. (B) The cluster ofIan-related genes. In human, this gene family is present on chromosome 7q36.1. In the mouse, it is located on proximal chromosome 6. We have also indicated the position of the human and mouse orthologs of the LR8/Clast1 (mouse accession no. AB031386) gene as location aids, although this gene is not in the IAN family. We have indicated various alternative names associated with each gene, and provisionally named previously unnamed members of the family as follows (these are indicated by underlines). For those genes without a common name, we have chosen to continue using the Ian gene nomenclature. To avoid confusion, in this work we will refer to the genes in this family by using the name of the mouse ortholog and a prefix, h, m, or r, to specify which species is indicated (e.g., hIan2 for the human ortholog of mouse Ian2, otherwise known as himap1). Genes given the same Ian designation in different species have been determined to be orthologs of each other. Genes with different designations do not show enough similarity to be deemed orthologs, with the exception of hIan7, which is orthologous to both mIan7 and mIan3. Genes in species without a clear ortholog in the other have been given unique Ian numbers (e.g., hIan12). Positions shown are within the respective contigs (accession nos. NT_007704.8‖Hs7_7861 for human and supercontig Mm6_WIFeb01_100 for mouse). (C) Diagram of the rat, mouse, and human Ian5 gene transcripts, with exon structure shown to scale. Beneath each transcript diagram is a diagram of the extent of the major ORF (the Ian5-coding region). Continued on the following page.
