SHORT COMMUNICATION Genetic Mapping of Three Human Homologues of Murine t-Complex Genes Localizes TCPI 0 to 6q27, 15 CM Distal to TCPI and PLG HELENE BLANC&, * LAWRENCE G. Wwxr, t GILLES VERGNAUD, $ BEATRICE DE GOUYON, * VALERIE LAUTHIER, $ LEE M. SILVER,~ JEAN DAUSSET,* HOWARD M. CANN, **’ AND RICHARD 5. SPtELMANt l Centre d/Etude du Polymorphisme Humain (CEPH), 75010 Paris, France; tDepartment of Human Genetics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104; SCentre d’ftudes du Bouchet, 9 1770 Vert le Petit, France; and §Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544 10 14 Received July 3, 1991; revised October 21, 1991 Human homologues of mouse t-complex genes have been cloned and localized physically to chromosome 6p or 6q. TCPl, TCPlO, and PLG are human homologues of genes lo- cated in the proximal portion of the t-complex on mouse chro- mosome 17. We present here results of genetic mapping of these human t-complex homologues previously localized to 6q25-q27,6q2 l-q27, and 6q26-q27, respectively, by physi- cal techniques. TCPl and PLG do not recombine with each other and are separated from TCPlO by about 15 CM, while the corresponding mouse genes are no more than 4 CM apart. Genetic mapping with markers well localized cytogenetically places TCPl and PLG proximal to TCPlO and localizes the latter to the cytogenetic band 6q27. It is likely that the organi- zation of human t-complex homologues on 6q is similar to that of t haplotypes rather than that of wildtype murine chromo- Some 17. 0 1992 Academic Press. Inc. Although human homologues of murine t-complex se- quences and genes have been identified, it is clear from mapping studies that they are organized differently from those of the mouse. In the mouse, the t-complex is in- cluded in a 12- to X-CM region in the proximal part of chromosome 17. Two forms of the t-complex, wildtype and t haplotypes, may be distinguished by linked poly- morphic markers and four inversions (56). It is becom- ing evident that human homologues of murine se- quences localized to the proximal segment of the t-com- plex are found on 6q and those of sequences in the distal part of the t-complex are localized to 6p (2). Human homologues of the murine loci Tcp-1 (TCPl, t-complex 1, in the human), Tcp-10 (TCPlO, t-complex 10, in the human), and Plg (PLG, human plasminogen), all found in the proximal portion of the t-complex (1, 5), have been localized to 6q25-q27,6q21-q27, and 6q26-q27, re- spectively, by physical mapping techniques (2,4, B), but there is no information on their genetic localization. The mouse Tcp-1 gene codes for an abundant testicular germ cell protein (ll), and one member of the Tcp-10 gene ’ To whom correspondence should be addressed at Centre d’Etude du Polymorphisme Humain, 27 rue Juliette Dodu, 75010 Paris, France. family cluster, expressed uniquely in the murine testis, is a candidate for the t-complex transmission ratio re- sponder locus (3). Although in the mouse Tcp-10 seems to be a complex locus containing a clustered gene family, there is no information on the structure of the human TCPlO locus. We have genetically mapped the human t-complex homologues, TCPl, PLG, and TCPlO, with respect to each other and to two other highly polymor- phic 6q markers and determined their orientation with respect to the centromere. Genotypes for six genetic markers (defining five loci; Table 1) were generated from DNA of lymphoblastoid cell lines from the 40 reference families of the CEPH panel. Southern blots were prepared by standard meth- ods (9). Autoradiograms of Southern blots were inter- preted independently by two individuals, and apparent recombinants between pairs of loci with recombination frequencies of 0.20 or less were checked extensively. Pairwise linkage analysis of the six markers was per- formed and a genetic map was constructed with the LINKAGE package of programs [version 5.1 (7)] on a Micro Vax II computer. Pairwise linkage analyses revealed absence of recombi- nation between TCPl and PLG and between the two RFLPs detected by T66 (locus TCPlO), supported by high lod scores (Table 2). All possible orders of PLG, TCPl, and the two TCPlO polymorphisms, TCPlO(2a) and TCPlO(Bb), were tested by multilocus linkage analy- sis, and the results of the pairwise lod score analysis for these markers were confirmed. Then, D6S132 was added to a two-point map consisting of (TCPl, PLG) and TCPlO fixed at a recombination frequency of 0.14 be- tween them. Locus D6S133 was added to this three- point map. The order of this preliminary map was D6S132-TCPlO-D6S133-(TCPl, PLG). All 360 orders of the six markers on the preliminary map were tested assuming no differences in recombina- tion rates between sexes. These included orders in which PLG was allowed to segregate independently of TCPl. Both polymorphisms of TCPlO were also allowed to seg- regate independently in the analysis. The most likely map order, shown in Fig. 1, is identical to the prelimi- nary map of five loci; D6S133 lies proximal and very GENOMICS 12,826-828 (1992) osas-7543/92 $3.00 Copyright 0 1992 by Academic Press, Inc. All rights of reproduction in any form reserved. 826