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THE GENETICAL SOCIETY—ABSTRACTS of PAPERS of A1059metdphageswas Isolated on Minimal 5 Heredity 62 (1989) 281—288 The Genetica! Society of Great Britain THEGENETICAL SOCIETY (Abstracts of papers presented at the TWO HUNDRED AND NINTH MEETING of the Society held from 11th to 12th November 1988 at UNIVERSITY COLLEGE, LONDON) 1. Neutrality of two alleles of 2. Molecular studies of bovine Esterase-5 in Drosophila anti-testosterone immunoglobulins pseudoobscura: a perturbation- T. Jackson,* D. J. Groves,t B. Morrist and P. reperturbation test G. Sanders* * Molecular Biology Group, Department of Einar Arnason Microbiology, and t AFRC Antibody Development Institute of Biology, University of Iceland, Reykjavik, Group, Department of Biochemistry, University of Iceland. Surrey, Guildford GU2 5XH, U.K. Weare interested in improving the therapeutic Aperturbation-reperturbation testsselective properties of ovine and bovine immunoglobulins neutrality of 100/100/100/100/100 and to hormones involved in the reproductive cycle. 106/100/100/100/100,thetwo most common A mouse-bovine heterohybridoma has been alleles at the highly polymorphic X-linked locus produced which secretes a monoclonal antibody Esterase-5 in Drosophila pseudoobscura. A total of against testosterone. In order to investigate the 22 replicate populations are set up in cages, 11 binding of this anti-steroid immunoglobulin to tes- populations start at a frequency of 76% and 11 at tosterone we have cloned cDNAs for both the 21% of the 106 allele. Allele frequencies change heavy and light chain proteins. Studies to charac- directionally and decrease in both high and low tense these clones will be presented. populations as groups and reach equilibria of respectively 60% and 14% after 200-300 days. The directed changes of allele frequencies are due to 3.Cloning studies of a methionine natural selection. A hypothesis of balancing selec- tion accounts for the pattern of allele frequency high-affinity transport system of changes and predicts a dynamic equilibrium. A Salmonella typhimurium neutral hypothesis equally well accounts for the N. A. Shaw and P. D. Ayling pattern leaving the Est-5 variants to drift at neutral equilibria. A reperturbation of allele frequencies Department of Applied Biology, University of Hull, in each population, creating 22 additional reper- Hull HU6 7RX, U.K. turbed populations with the original populations Thehigh-affinity methionine transport system of as controls, directly addresses the question of Salmonella typhimurium (encoded by the metD balancing selection or dissipated linkage effects. locus, formerly called metP) is believed to be of Allele frequencies do not change directionally the shock-sensitive category (Cottam and Ayling, among the reperturbed populations as a group. unpublished), and therefore should consist of one The hypothesis of balancing selection is rejected periplasmic and at least two inner membrane pro- in favor of the hypothesis of dissipated linkage teins (Ames, G. F. L., 1986, Ann. Rev. Biochem., effects. In conclusion the 100/100/100/100/100 55, 379). A library of a partial Sau 3A digest of S. and 106/100/100/100/100 are iso-fitness alleles of typhimurium DNA in the replacement vector, Est-5 A 1059, was obtained from Dr. R. Maurer. A series 282 THE GENETICAL SOCIETY—ABSTRACTS OF PAPERS of A1059metDphageswas isolated on minimal 5. Identification of a putative B- agar plus D-methionine by lysogenic corn- plementation of an E.coli metD mutant.One of chromosome specific sequence the clones was shown to have retained the activity from rye (Secale cereale) of a high-affinity methionine transport system. The metDinsertwas subcloned into the high M. J. Sandery, J. W. Forster and R. N. Jones copy number plasmid, pUC8, and four metD Genetic and Crop Biotechnology Group, Department isolates were selected in an E. coli metD strain. A of Agricultural Sciences, University College of clone carrying pUC8 with a 1.4 kilobase insert gave Wales, Aberystwyth, Dyfed SY23 3DD, U.K. a methionine uptake rate which was 30% that of DNAfrom a rye plant containing 611-chromosomes an E. coli metD strain, and showed slow growth was compared by restriction enzyme analysis with on D-methionine medium. Three other larger DNA from a plant lacking B-chromosomes. With metD plasmids gave wild-type or increased levels the restriction enzyme Dra 1, the 6B restriction of methionine transport. pattern shows the presence of a highly repeated Expression studies using in vitro and minicell DNA sequence, about 1200 bp in length, which is methods showed that the larger metD plasmids not visible in the OB restriction pattern. This encoded two additional proteins of molecular repeated sequence has been isolated and used as weight 40 and 34 kDal. Neither of these proteins a probe to investigate whether the sequence is appeared to be a periplasmic binding protein. B-chromosome specific, its relation to other rye repeated sequences and its position in the rye B 4.Conservation of a human chromosome. derived Y-specific sequence on the Y chromosome of the great apes 6.Detection of Ig and TcR gene M. Kalaitsidaki,* K. Kwok,t M. A. Ferguson- rearrangement in human Smith and J. M. Conner* lymphomas * Duncan Guthrie Institute of Medical Genetics, Glasgow G3 8SJ, U.K. v. Orphanos*, D. Anagnostou,t Th. tAFRCInstitute of Animal Physiology and Genetics Papadaki,t G. M. Maniatis* and A. Research, Cambridge, U.K. Atha n ass iado u * 1 Department of Pathology, Cambridge CB2 lOP, * Department of Biology, Medical School, University U.K. of Patras, Patras, Greece. GM6YIO,a human derived repetitive sequence, Laboratory of Hematopathology, General Hospital specific for the short arm of the Y chromosome, of Athens, "EVANGELIMOS'ç Athens, Greece. was shown by Southern blot analysis to hybridise Igand T cell receptor gene arrangements represent with DNA from male gorilla (Gorilla gorilla), male markers of lineage, clonality and differentiation of orangutan (Pongo pvgrnaeus) and male chimpan- B and T cells respectively. Detection of such zee (Pan troglodytes). To investigate its chromo- rearrangements in B and T cell neoplasms has somal localisation the sequence was utilised in in provided the basis for their molecular diagnosis situ hybridisation studies with metaphase chromo- and classification particularly in severe cases where somes obtained from chimpanzee, orangutan and immunological analysis seems to be unable to gorilla fibroblasts. GMGYIO was labelled by nick define lineage and clonality. We used probes which translation with biotin-1 1-dUTP and hybridisation detect rearrangements of the Ig heavy (JH)and was carried out according to the method of Garson k-light (CK)chaingenes or the TcR 13-chain (Co) er a!. (Nucleic Acids Res., 15, 4761—4770). and y-chain (Tv) genes and proceeded to genotypic Hybridisation signal was observed on the Y analysis of various cases of lymphoproliferative chromosome in all 3 cases. In the orangutan, there disorders. was signal only on the short arm of the Y, whereas Our results on CLL, Hodgkin's disease and in the gorilla the majority of the signal was non-Hodgkin's lymphomas agree with those re- observed on the long arm. In the chimpanzee it ported in the literature (O'Connor, N. I. J., 1987, was not possible to decide whether the signal .1. Pathology, 151, 185—190). occurred on the short or the long arm because the Reactive processes and lymphornas of double Y chromosome is particularly small. The possible phenotype is our main interest. Among the reactive significance of these findings is discussed. processes we detect cases of T cell lymphoma THE GENETICAL SOCIETY—ABSTRACTS OF PAPERS 283 (TcR gene rearranged-Ig genes in germline Mycobacterium paratuberculosis (paratb) is the configuration) as well as of B cell lymphomas (Ig causative agent of Johne's disease (regional genes rearranged-TcR gene in germline configu- enteritis) in ruminants. It is very closely related to ration or deleted). One of the former cases was Mycobacterium avium with which it shares 98% confirmed a year later as a T cell lymphoma by DNA homology (McFadden, J. J., 1988, J. Clin. immunocytochemical analysis. We are currently Microbiol., 25,796—801).However, M. avium using a TcR (y) probe in the analysis of reactive causes only sporadic disease in ruminants, whereas processes in order to obtain data concerning the paratb is a major pathogen causing chronic, fatal, differentiation of these processes. wasting disease. Conversely, unlike paratb, M Ig and TcR genes were rearranged while TcRy avium is a pathogen of birds. Paratb also differs gene was in germline in the three cases of lym- from M. aviuni in its requirement for an iron- phomas of double phenotype (B cell lymphomas) chelating growth factor (mycobactin) for growth studied so far. The evaluation of the usefulness of and in its extremely slow growth rate. We have TcR gene rearrangements in the genotypic analy- isolated and characterised a mycobacterial inser- sis of these lymphomas is also desired. Analysis tion sequence (MIS1) which is present in identical of further cases is in progress. multiple copies in the genomes of all strains of paratb, but absent from all strains of M. avium. We propose that infection of an M. avium strain 7.Selection in karyotypic hybrid with MIS! has recently occurred leading to the zones rapid evolution of the species M. para tuberculosis. We also propose that insertional mutagenesis may J. B. Searle account for the multiple phenotypic differences between paratb and M. aviurn. The newly evolved, Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, U.K. debilitated paratb may be an example of what Goldschmidt (The Material Basis of Evolution, Heterozygotesfor chromosomal (structural) re- 1940) termed a "hopeful monster". arrangements produced when karyotypic races hybridize in nature are expected to suffer reduced fertility relative to "pure" race individuals, as a 9. result of chromosomal imbalance or loss among Analysis of dines and linkage germ cells, associated with meiotic aberrations.
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