scholarly journals Genetic exchange across a paracentric inversion of the mouse t complex.

Genetics ◽  
1991 ◽  
Vol 128 (4) ◽  
pp. 799-812 ◽  
Author(s):  
M F Hammer ◽  
S Bliss ◽  
L M Silver
Keyword(s):  
Inbred Strains ◽  
Genetic Exchange ◽  
Transmission Ratio Distortion ◽  
Chromosome 17 ◽  
Wild Type ◽  
T Complex ◽  
Haplotype Allele ◽  
Hybrid Allele ◽  
Paracentric Inversions ◽  
T Haplotype

Abstract Mouse t haplotypes are distinguished from wild-type forms of chromosome 17 by four nonoverlapping paracentric inversions which span a genetic distance of 20 cM. These inversion polymorphisms are responsible for a 100-200-fold suppression of recombination which maintains the integrity of complete t haplotypes and has led to their divergence from the wild-type chromosomes of four species of house mice within which t haplotypes reside. As evidence for the long period of recombinational isolation, alleles that distinguish all t haplotypes from all wild-type chromosomes have been established at a number of loci spread across the 20-cM variant region. However, a more complex picture emerges upon analysis of other t-associated loci. In particular, "mosaic haplotypes" have been identified that carry a mixture of wild-type and t-specific alleles. To investigate the genetic basis for mosaic chromosomes, we conducted a comprehensive analysis of eight t complex loci within 76 animals representing 10 taxa in the genus Mus, and including 23 previously characterized t haplotypes. Higher resolution restriction mapping and sequence analysis was also performed for alleles at the Hba-ps4 locus. The results indicate that a short tract of DNA was transferred relatively recently across an inversion from a t haplotype allele of Hba-ps4 to the corresponding locus on a wild-type homolog leading to the creation of a new hybrid allele. Several classes of wild-type Hba-ps4 alleles, including the most common form in inbred strains, appear to be derived from this hybrid allele. The accumulated data suggest that a common form of genetic exchange across one of the four t-associated inversions is gene conversion at isolated loci that do not play a role in the transmission ratio distortion phenotype required for t haplotype propagation. The implications of the results pose questions concerning the evolutionary stability of gene complexes within large paracentric inversions and suggest that recombinational isolation may be best established for loci residing within a short distance from inversion breakpoints.

scholarly journals Distorter genes of the mouse t-complex impair male fertility when heterozygous

1987 ◽  
Vol 49 (1) ◽  
pp. 57-60 ◽  
Author(s):  
Mary F. Lyon
Keyword(s):  
Male Fertility ◽  
Genetic Background ◽  
Inbred Strains ◽  
Transmission Ratio Distortion ◽  
Chromosome 17 ◽  
Male Mice ◽  
Wild Type ◽  
T Complex ◽  
Ratio Distortion ◽  
Harmful Effects

SummaryMale mice heterozygous for two distorter genes, Tcd-1 and Tcd-2, of the mouse t-complex but homozygous wild type for the responder, were generated by crossing animals carrying the partial t-haplotypes th51 and th18 to inbred strains. The fertility of these males was then compared with that of their brothers carrying normal chromosome 17s. On three of the inbred backgrounds used, C3H/HeH, C57BL/6J and TFH/H, the th51th18 + / + + + males were significantly less fertile than their normal sibs. With the fourth inbred strain used, SM/JH, both types of male were nonnally fertile. This confirmed earlier preliminary findings that when both homologues of chromosome 17 carry wild-type alleles of the responder, heterozygosity for the distorter genes is sufficient to impair fertility, but the effect varies with genetic background. These results are consistent with the concept that both the transmission ratio distortion and the male sterility caused by the t-complex are due to harmful effects of the distorter genes on wild-type alleles of the responder.

scholarly journals Genetic evidence for two t complex tail interaction (tct) loci in t haplotypes.

Genetics ◽  
1989 ◽  
Vol 122 (4) ◽  
pp. 895-903
Author(s):  
J H Nadeau ◽  
D Varnum ◽  
D Burkart
Keyword(s):  
Genetic Analysis ◽  
Tail Length ◽  
Genetic Interactions ◽  
Chromosome 17 ◽  
Wild Type ◽  
T Complex ◽  
Inverted Duplication ◽  
Haplotype A ◽  
Recombination Breakpoints ◽  
T Haplotype

Abstract The t complex on chromosome 17 of the house mouse is an exceptional model for studying the genetic control of transmission ratio, gametogenesis, and embryogenesis. Partial haplotypes derived through rare recombination between a t haplotype and its wild-type homolog have been essential in the genetic analysis of these various properties of the t complex. A new partial t haplotype, which was derived from the complete tw71 haplotype and which is called tw71Jr1, was shown to have unexpected effects on tail length and unique recombination breakpoints. This haplotype, either when homozygous or when heterozygous with the progenitor tw71 haplotype, produced short-tailed rather than normal-tailed mice on certain genetic backgrounds. Genetic analysis of this exceptional haplotype showed that the recombination breakpoints were different from those leading to any other partial t haplotype. Based on this haplotype, a model is proposed that accounts for genetic interactions between the brachyury locus (T), the t complex tail interaction (tct) locus, and their wild-type homolog(s) that determine tail length. An important part of this model is the hypothesis that the tct locus, which enhances the tail-shortening effect of T mutations, is in fact at least two, genetically separable genes with different genetic activities. Genetic analysis of parental and recombinant haplotypes also suggests that intrachromosomal recombination involving an inverted duplicated segment can account for the variable orientation of loci within an inverted duplication on wild-type homologs of the t haplotype.

Identification of a germ-cell-specific transcriptional repressor in the promoter of Tctex-1

Development ◽  
1995 ◽  
Vol 121 (2) ◽  
pp. 561-568 ◽  
Author(s):  
M.J. O'Neill ◽  
K. Artzt
Keyword(s):  
Germ Cell ◽  
Gene Family ◽  
Binding Site ◽  
Transcriptional Repressor ◽  
Chromosome 17 ◽  
Wild Type ◽  
Aberrant Expression ◽  
T Complex ◽  
T Haplotype

The Tctex-1 gene family maps to the t complex of the mouse and consists of four copies on chromosome 17 in both wild-type and t-haplotypes. Tctex-1 mRNA is eightfold overexpressed in male and female germ cells in t-haplotype compound heterozygotes (tx/ty). In order to determine the cause of this aberrant expression and the role of this gene family in spermatogenesis and oogenesis it was subjected to extensive molecular analysis. We find that Tctex-1 protein is present in sperm tails and oocytes and that it is present at equal levels in wild-type and t-haplotype testis. Surprisingly, the excess message in t-haplotypes is not translated. Sequence analysis of the gene family reveals that one copy in t-haplotypes has a mutated start codon. This same copy is deleted for a protein-binding motif in its promoter. This motif, GIM (Germ cell Inhibitory Motif) has strong homology to the Xenopus AP-2-binding site but does not appear to be a binding site for mammalian AP-2. A factor(s) present in testis and ovary, but absent in other mouse tissues binds specifically to this site. Transfection assays using Tctex-1 promoter constructs suggest that GIM functions as a transcriptional repressor. The possible role of Tctex-1 in t complex transmission ratio distortion and sterility is discussed.

The Putative Oncogene Pim-1 in the Mouse: Its Linkage and Variation Among t Haplotypes

Genetics ◽  
1987 ◽  
Vol 117 (3) ◽  
pp. 533-541
Author(s):  
Joseph H Nadeau ◽  
Sandra J Phillips
Keyword(s):  
Restriction Fragment ◽  
Inbred Mice ◽  
Globin Gene ◽  
Inbred Strains ◽  
Chromosome 17 ◽  
Wild Type ◽  
Alpha Crystallin ◽  
T Complex ◽  
Variant Alleles ◽  
Apparent Association

ABSTRACT Pim-1, a putative oncogene involved in T-cell lymphomagenesis, was mapped between the pseudoalpha globin gene Hba-4ps and the alpha-crystallin gene Crya-1 on mouse chromosome 17 and therefore within the t complex. Pim-1 restriction fragment variants were identified among t haplotypes. Analysis of restriction fragment sizes obtained with 12 endonucleases demonstrated that the Pim-1 genes in some t haplotypes were indistinguishable from the sizes for the Pim-1b allele in BALB/c inbred mice. There are now three genes, Pim-1, Crya-1 and H-2 I-E, that vary among independently derived t haplotypes and that have indistinguishable alleles in t haplotypes and inbred strains. These genes are closely linked within the distal inversion of the t complex. Because it is unlikely that these variants arose independently in t haplotypes and their wild-type homologues, we propose that an exchange of chromosomal segments, probably through double crossingover, was responsible for indistinguishable Pim-1 genes shared by certain t haplotypes and their wild-type homologues. There was, however, no apparent association between variant alleles of these three genes among t haplotypes as would be expected if a single exchange introduced these alleles into t haplotypes. If these variant alleles can be shown to be identical to the wild-type allele, then lack of association suggests that multiple exchanges have occurred during the evolution of the t complex.

scholarly journals Narrowing the Critical Regions for Mouse t Complex Transmission Ratio Distortion Factors by Use of Deletions

Genetics ◽  
2000 ◽  
Vol 155 (2) ◽  
pp. 793-801 ◽  
Author(s):  
Mary F Lyon ◽  
John C Schimenti ◽  
Edward P Evans
Keyword(s):  
Transmission Ratio Distortion ◽  
Chromosome 17 ◽  
Transmission Ratio ◽  
Critical Interval ◽  
Enhanced Transmission ◽  
T Complex ◽  
Ratio Distortion ◽  
Critical Regions ◽  
Complex Transmission ◽  
T Haplotype

Abstract Previously a deletion in mouse chromosome 17, T22H, was shown to behave like a t allele of the t complex distorter gene Tcd1, and this was attributed to deletion of this locus. Seven further deletions are studied here, with the aim of narrowing the critical region in which Tcd1 must lie. One deletion, T30H, together with three others, T31H, T33H, and T36H, which extended more proximally, caused male sterility when heterozygous with a complete t haplotype and also enhanced transmission ratio of the partial t haplotype t 6, and this was attributed to deletion of the Tcd1 locus. The deletions T29H, T32H, and T34H that extended less proximally than T30H permitted male fertility when opposite a complete t haplotype. These results enabled narrowing of the critical interval for Tcd1 to between the markers D17Mit164 and D17Leh48. In addition, T29H and T32H enhanced the transmission ratio of t6, but significantly less so than T30H. T34H had no effect on transmission ratio. These results could be explained by a new distorter located between the breakpoints of T29H and T34H (between T and D17Leh66E). It is suggested that the original distorter Tcd1 in fact consists of two loci: Tcd1a, lying between D17Mit164 and D17Leh48, and Tcd1b, lying between T and D17Leh66E.

scholarly journals Genetic and molecular analysis of the proximal region of the mouse t-complex using new molecular probes and partial t-haplotypes.

Genetics ◽  
1990 ◽  
Vol 126 (4) ◽  
pp. 1103-1114 ◽  
Author(s):  
C A Howard ◽  
G R Gummere ◽  
M F Lyon ◽  
D Bennett ◽  
K Artzt
Keyword(s):  
Wild Mouse ◽  
Molecular Probes ◽  
Proximal Region ◽  
Chromosome 17 ◽  
Lethal Gene ◽  
Strong Linkage Disequilibrium ◽  
Wild Type ◽  
T Complex ◽  
Naturally Occurring ◽  
Normal Transmission

Abstract The t-complex is located on the proximal third of chromosome 17 in the house mouse. Naturally occurring variant forms of the t-complex, known as complete t-haplotypes, are found in wild mouse populations. The t-haplotypes contain at least four nonoverlapping inversions that suppress recombination with the wild-type chromosome, and lock into strong linkage disequilibrium loci affecting normal transmission of the chromosome, male gametogenesis and embryonic development. Partial t-haplotypes derived through rare recombination between t-haplotypes and wild-type homologs have been critical in the analysis of these properties. Utilizing two new DNA probes. Au3 and Au9, and several previously described probes, we have analyzed the genetic structure of several partial t-haplotypes that have arisen in our laboratory, as well as several wild-type chromosomes deleted for loci in this region. With this approach we have been able to further our understanding of the structural and dynamic characteristics of the proximal region of the t-complex. Specifically, we have localized the D17Tul locus as most proximal known in t-haplotypes, achieved a better structural analysis of the partial t-haplotype t6, and defined the structure and lethal gene content of partial t-haplotypes derived from the lethal tw73 haplotype.

scholarly journals t-Specific DNA polymorphisms among wild mice from Israel and Spain.

Genetics ◽  
1988 ◽  
Vol 119 (1) ◽  
pp. 157-160
Author(s):  
F Figueroa ◽  
E Neufeld ◽  
U Ritte ◽  
J Klein
Keyword(s):  
Laboratory Mouse ◽  
The Other ◽  
Dna Polymorphisms ◽  
Chromosome 17 ◽  
Mouse Strains ◽  
Laboratory Mice ◽  
Wild Type ◽  
Wild Mice ◽  
T Complex ◽  
Length Polymorphisms

Abstract Lehrach and his coworkers have isolated a series of DNA probes that specifically hybridize with different regions of mouse chromosome 17 within the t complex. The probes display restriction fragment length polymorphisms, RFLPs, which are specific for the t haplotypes in all laboratory mouse strains tested thus far. Some of these probes have been used to test wild mice populations for these t-associated DNA forms. It is demonstrated that populations from Germany, Switzerland, Italy, Greece, Yugoslavia, Australia, Costa Rica, and Venezuela contain chromosomes in which all the tested DNA loci display the t-specific polymorphisms. The frequency of mice carrying these chromosomes is as high as 31%. Wild mice from Israel and Spain, on the other hand, carry chromosomes displaying t-specific DNA forms only at one or two of the probed loci, while the other loci carry the wild-type (+) forms. These chromosomes thus resemble the partial t haplotypes known from the study of laboratory mice. One possible interpretation of these findings is that these DNA polymorphisms contributed to the assembly of the complete t haplotypes and that these haplotypes may have originated in the Middle East.

scholarly journals LC2, the Chlamydomonas Homologue of the tComplex-encoded Protein Tctex2, Is Essential for Outer Dynein Arm Assembly

1999 ◽  
Vol 10 (10) ◽  
pp. 3507-3520 ◽  
Author(s):  
Gregory J. Pazour ◽  
Anthony Koutoulis ◽  
Sharon E. Benashski ◽  
Bethany L. Dickert ◽  
Hong Sheng ◽  
...  
Keyword(s):  
Transmission Ratio Distortion ◽  
Transmission Ratio ◽  
Wild Type ◽  
Gene Encoding ◽  
Ratio Distortion ◽  
Differential Binding ◽  
Phenotype Transformation ◽  
Essential Subunit ◽  
Complete Deletion ◽  
T Haplotype

Tctex2 is thought to be one of the distorter genes of the mouset haplotype. This complex greatly biases the segregation of the chromosome that carries it such that in heterozygous +/t males, the t haplotype is transmitted to >95% of the offspring, a phenomenon known as transmission ratio distortion. The LC2 outer dynein arm light chain ofChlamydomonas reinhardtii is a homologue of the mouse protein Tctex2. We have identified Chlamydomonasinsertional mutants with deletions in the gene encoding LC2 and demonstrate that the LC2 gene is the same as the ODA12 gene, the product of which had not been identified previously. Complete deletion of the LC2/ODA12 gene causes loss of all outer arms and a slow jerky swimming phenotype. Transformation of the deletion mutant with the cloned LC2/ODA12 gene restores the outer arms and rescues the motility phenotype. Therefore, LC2 is required for outer arm assembly. The fact that LC2 is an essential subunit of flagellar outer dynein arms allows us to propose a detailed mechanism whereby transmission ratio distortion is explained by the differential binding of mutant (t haplotype encoded) and wild-type dyneins to the axonemal microtubules oft-bearing or wild-type sperm, with resulting differences in their motility.

scholarly journals Recent evolution of mouse t haplotypes at polymorphic microsatellites associated with the t complex responder (Tcr) locus

1996 ◽  
Vol 67 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Kristin G. Ardlie ◽  
Lee M. Silver
Keyword(s):  
Field Studies ◽  
Complementation Group ◽  
Transmission Ratio Distortion ◽  
Chromosome 17 ◽  
Recent Common Ancestor ◽  
Central Component ◽  
Wild Mice ◽  
T Complex ◽  
Founding Population ◽  
Ratio Distortion

SummaryMicrosatellites closely associated with each member of the Tcp1O gene family were amplified simultaneously from t haplotype and wild-type forms of mouse chromosome 17, by PCR. The t complex responder (Tcr) locus, which plays a central role in transmission ratio distortion, maps within the Tcp10 cluster on the t haplotype. Thus the amplified set of microsatellite loci (referred to collectively as Tcp10ms) provides a direct marker for this central component of the meiotic drive system associated with all naturally occurring t haplotypes. A unique Tcp10ms pattern of microsatellite alleles was obtained for a number of independent, laboratory-maintained complete and partial t haplotypes. Independent t chromosomes found in wild mice from US populations also had unique patterns, even when they were classified within the same lethal complementation group. Wild and laboratory chromosomes in the tw5 group showed similarly-sized but non-identical Tcp10ms patterns, suggesting they share a recent common ancestor. These chromosomes are likely to have derived from an ancestral chromosome within the founding population of North American house mice. The Tcp10ms pattern was also shown to be useful in field studies for distinguishing among independentt haplotypes, when more than one is present within a single population.

scholarly journals Deletion analysis of male sterility effects of t–haplotypes in the mouse

1990 ◽  
Vol 56 (2-3) ◽  
pp. 179-183 ◽  
Author(s):  
Dorothea Bennett ◽  
Karen Artzt
Keyword(s):  
Male Sterility ◽  
Deletion Analysis ◽  
Transmission Ratio Distortion ◽  
Chromosome 17 ◽  
Transmission Ratio ◽  
Wild Type ◽  
Ratio Distortion ◽  
Very High

SummaryWe present data on the effects of three chromosome 17 deletions on transmission ratio distortion (TRD) and sterility of several t-haplotypes. All three deletions have similar effects on male TRD: that is, Tdel/tcomplete genotypes all transmit their t–haplotype in very high proportion. However, each deletion has different effects on sterility of heterozygous males, with Tor/t being fertile, Thp/t less fertile, and Torl/t still less fertile. These data suggest that wild-type genes on chromosomes homologous to f-haplotypes can be important regulators of both TRD and fertility in males, and that the wild-type genes concerned with TRD and fertility are at least to some extent different. The data also provide a rough map of the positions of these genes.

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