scholarly journals Genetic organization of the unc-60 region in Caenorhabditis elegans.

Genetics ◽  
1988 ◽  
Vol 118 (1) ◽  
pp. 49-59
Author(s):  
K S McKim ◽  
M F Heschl ◽  
R E Rosenbluth ◽  
D L Baillie
Keyword(s):  
Caenorhabditis Elegans ◽  
Linkage Group ◽  
Gene Order ◽  
Chromosomal Region ◽  
Essential Genes ◽  
Ethyl Methanesulfonate ◽  
Induced Mutations ◽  
Nematode Caenorhabditis Elegans ◽  
Genetic Organization ◽  
Muscle Structure

Abstract We have investigated the chromosomal region around unc-60 V, a gene affecting muscle structure, in the nematode Caenorhabditis elegans. The region studied covers 3 map units and lies at the left end of linkage group (LG) V. Compared to the region around dpy-11 (at the center of LGV), the unc-60 region has relatively few visible genes per map unit. We found the same to be true for essential genes. By screening simultaneously for recessive lethals closely linked to either dpy-11 or unc-60, we recovered ethyl methanesulfonate-induced mutations in 10 essential genes near dpy-11 but in only two genes near unc-60. Four deficiency breakpoints were mapped to the unc-60 region. Using recombination and deficiency mapping we established the following gene order: let-336, unc-34, let-326, unc-60, emb-29, let-426. Regarding unc-60 itself, we compared the effect of ten alleles (including five isolated during this study) on hermaphrodite mobility and fecundity. We used intragenic mapping to position eight of these alleles. The results show that these alleles are not distributed uniformly within the gene, but map to two groups approximately 0.012 map unit apart.

CAENORHABDITIS ELEGANS DEFICIENCY MAPPING

Genetics ◽  
1984 ◽  
Vol 108 (2) ◽  
pp. 331-345
Author(s):  
D Christine Sigurdson ◽  
Gail J Spanier ◽  
Robert K Herman
Keyword(s):  
Caenorhabditis Elegans ◽  
Linkage Group ◽  
Ethyl Methanesulfonate ◽  
Single Site ◽  
Crossing Over ◽  
Wild Type ◽  
Nematode Caenorhabditis Elegans ◽  
Recessive Lethal ◽  
X Ray ◽  
New Mutations

ABSTRACT Six schemes were used to identify 80 independent recessive lethal deficiencies of linkage group (LG) II following X-ray treatment of the nematode Caenorhabditis elegans. Complementation tests between the deficiencies and ethyl methanesulfonate-induced recessive visible, lethal and sterile mutations and between different deficiencies were used to characterize the extents of the deficiencies. Deficiency endpoints thus helped to order 36 sites within a region representing about half of the loci on LG II and extending over about 5 map units. New mutations occurring in this region can be assigned to particular segments of the map by complementation tests against a small number of deficiencies; this facilitates the assignment of single-site mutations to particular genes, as we illustrate. Five sperm-defective and five oocyte-defective LG II sterile mutants were identified and mapped. Certain deficiency-by-deficiency complementation tests allowed us to suggest that the phenotypes of null mutations at two loci represented by visible alleles are wild type and that null mutations at a third locus confer a visible phenotype. A segment of LG II that is about 12 map units long and largely devoid of identified loci seems to be greatly favored for crossing over.

scholarly journals ESSENTIAL GENES AND DEFICIENCIES IN THE UNC-22 IV REGION OF CAENORHABDITIS ELEGANS

Genetics ◽  
1982 ◽  
Vol 102 (4) ◽  
pp. 725-736
Author(s):  
Teresa M Rogalski ◽  
Donald G Moerman ◽  
David L Baillie
Keyword(s):  
Caenorhabditis Elegans ◽  
Unit Interval ◽  
Essential Genes ◽  
The Other ◽  
Nematode Caenorhabditis Elegans ◽  
Muscle Structure ◽  
Lethal Mutations ◽  
Recombination Mapping ◽  
Wide Range ◽  
The Right

ABSTRACT Five formaldehyde-induced deficiencies that uncover unc-22 IV, a gene affecting muscle structure in the nematode Caenorhabditis elegans were isolated and positioned. The largest deficiency, sDf2, extends in both directions from unc-22 and is approximately 1.0-2.0 map units in length. The other four deficiencies, sDf7, sDf8, sDf9 and sDf10, are all smaller than sDf2 and are located within the region uncovered by this deficiency. Thirty-seven ethyl methanesulfonate-induced lethal and sterile mutations linked to unc-22 were isolated and tested for complementation with sDf2. Nineteen lethal mutations failed to complement sDf2. Sixteen of these were further positioned by recombination mapping and also by deficiency mapping with sDf7, sDf8, sDf9 and sDf10. These sixteen mutations define 11 new essential genes in this region. Eight of the genes lie in a 0.9-map unit interval to the left of unc-22, whereas the three remaining genes lie in a region of about 0.2 map units to the right of unc-22. We believe that two of the essential genes identified in this study, let-56 and let-52, are the adjacent genes on either side of unc-22. The lethal mutations exhibit a wide range of terminal phenotypes: from first stage larva to sterile adult.

scholarly journals GENETIC ORGANIZATION OF THE REGION AROUND UNC-15 (I), A GENE AFFECTING PARAMYOSIN IN CAENORHABDITIS ELEGANS

Genetics ◽  
1980 ◽  
Vol 96 (3) ◽  
pp. 639-648 ◽  
Author(s):  
A M Rose ◽  
D L Baillie
Keyword(s):  
Fine Structure ◽  
Caenorhabditis Elegans ◽  
Muscle Protein ◽  
Average Distance ◽  
Unit Interval ◽  
Essential Genes ◽  
Induced Mutations ◽  
Nematode Caenorhabditis Elegans ◽  
Biochemical Studies ◽  
Complementation Groups

ABSTRACT In the nematode Caenorhabditis elegans mutants in the gene unc-15 (I) affect the muscle protein paramyosin (Waterston, Fishpool and Brenner 1977). We have characterized 20 ethyl methanesulfonate-induced mutations in essential genes closely linked to unc-15. These lethals defined 16 new complementation groups. In the 0.65 map-unit interval around unc-15 defined by dpy-14 and unc-56, seven newly identified genes have been mapped relative to five existing genes. At present, the average distance between genes in this region is approximately 0.05 map units. Two genes, unc-15 and unc-13, are only 0.025 map units apart. Partial fine-structure maps of alleles of these two genes have been constructed. This analysis of unc-15 and genes adjacent to it is the first in a series of genetic and biochemical studies directed towards understanding the control of unc-15 expression.

Maternal-effect lethal mutations on linkage group II of Caenorhabditis elegans.

Genetics ◽  
1988 ◽  
Vol 120 (4) ◽  
pp. 977-986
Author(s):  
K J Kemphues ◽  
M Kusch ◽  
N Wolf
Keyword(s):  
Caenorhabditis Elegans ◽  
Linkage Group ◽  
Maternal Effect ◽  
Essential Genes ◽  
The Other ◽  
C Elegans ◽  
Lethal Mutations ◽  
Embryonic Lethal ◽  
Embryonic Lethal Mutations ◽  
F1 Progeny

Abstract We have analyzed a set of linkage group (LG) II maternal-effect lethal mutations in Caenorhabditis elegans isolated by a new screening procedure. Screens of 12,455 F1 progeny from mutagenized adults resulted in the recovery of 54 maternal-effect lethal mutations identifying 29 genes. Of the 54 mutations, 39 are strict maternal-effect mutations defining 17 genes. These 17 genes fall into two classes distinguished by frequency of mutation to strict maternal-effect lethality. The smaller class, comprised of four genes, mutated to strict maternal-effect lethality at a frequency close to 5 X 10(-4), a rate typical of essential genes in C. elegans. Two of these genes are expressed during oogenesis and required exclusively for embryogenesis (pure maternal genes), one appears to be required specifically for meiosis, and the fourth has a more complex pattern of expression. The other 13 genes were represented by only one or two strict maternal alleles each. Two of these are identical genes previously identified by nonmaternal embryonic lethal mutations. We interpret our results to mean that although many C. elegans genes can mutate to strict maternal-effect lethality, most genes mutate to that phenotype rarely. Pure maternal genes, however, are among a smaller class of genes that mutate to maternal-effect lethality at typical rates. If our interpretation is correct, we are near saturation for pure maternal genes in the region of LG II balanced by mnC1. We conclude that the number of pure maternal genes in C. elegans is small, being probably not much higher than 12.

scholarly journals The unc-22(IV) region of Caenorhabditis elegans: genetic analysis of lethal mutations.

Genetics ◽  
1988 ◽  
Vol 119 (2) ◽  
pp. 345-353
Author(s):  
D V Clark ◽  
T M Rogalski ◽  
L M Donati ◽  
D L Baillie
Keyword(s):  
Caenorhabditis Elegans ◽  
Linkage Group ◽  
Essential Gene ◽  
Group Iv ◽  
Essential Genes ◽  
Ems Mutagenesis ◽  
Lethal Mutations ◽  
Complementation Groups ◽  
Minimum Estimate ◽  
Caenorhabditis Elegans Genome

Abstract The organization of essential genes in the unc-22 region, defined by the deficiency sDf2 on linkage group IV, has been studied. Using the balancer nT1 (IV;V), which suppresses recombination over 49 map units, 294 lethal mutations on LGIV(right) and LGV(left) were recovered using EMS mutagenesis. Twenty-six of these mutations fell into the unc-22 region. Together with previously isolated lethal mutations, there is now a total of 63 lethal mutations which fall into 31 complementation groups. Mutations were positioned on the map using eight overlapping deficiencies in addition to sDf2. The lethal alleles and deficiencies in the unc-22 region were characterized with respect to their terminal phenotypes. Mapping of these lethal mutations shows that sDf2 deletes a minimum of 1.8 map units and a maximum of 2.5 map units. A minimum estimate of essential gene number for the region using a truncated Poisson calculation is 48. The data indicate a minimum estimate of approximately 3500 essential genes in the Caenorhabditis elegans genome.

scholarly journals Genetic Analysis of Adult-Specific Surface Antigenic Differences Between Varieties of the Nematode Caenorhabditis elegans

Genetics ◽  
1987 ◽  
Vol 117 (3) ◽  
pp. 467-476
Author(s):  
Samuel M Politz ◽  
Karl J Chin ◽  
Daniel L Herman
Keyword(s):  
Caenorhabditis Elegans ◽  
Linkage Group ◽  
Genetic Analysis ◽  
Surface Antigen ◽  
Single Gene ◽  
Surface Antigens ◽  
Nematode Caenorhabditis Elegans ◽  
Specific Antibodies ◽  
C Elegans ◽  
Stage Specificity

ABSTRACT We have studied developmental stage-specificity and genetic specification of surface antigens in the nematode Caenorhabditis elegans. Rabbit antisera directed against the adult C. elegans cuticle were used in conjunction with antiserum adsorption experiments to obtain antibody reagents with specificity for the adult surface. Adult-specific antibodies were used to identify several varietal strains of C. elegans that display antigen-negative phenotypes as adults. Genetic mapping results using the surface antigen phenotype as a marker indicated that a single gene (designated srf-1) or cluster of genes on linkage group II determines the adult surface antigen phenotype.

Genetic mapping of the 5S rRNA gene cluster of the nematode Caenorhabditis elegans

1986 ◽  
Vol 28 (4) ◽  
pp. 545-553 ◽  
Author(s):  
D. W. Nelson ◽  
B. M. Honda
Keyword(s):  
Caenorhabditis Elegans ◽  
Linkage Group ◽  
Gene Cluster ◽  
5S Rrna ◽  
Rrna Gene ◽  
Nematode Caenorhabditis Elegans ◽  
Group V ◽  
Length Difference ◽  
5S Rrna Gene ◽  
Restriction Fragment Length

We have identified a restriction fragment length difference (RFLD) affecting the genomic sequences immediately flanking the 5S rRNA gene cluster in the Bristol and Bergerac strains of the nematode Caenorhabditis elegans. We have used this RFLD as a molecular marker to follow the segregation of the 5S rRNA gene cluster through a series of two- and three-factor interstrain crosses. Our results show that the 5S rRNA gene cluster maps between unc-76 and dpy-21 on the right arm of linkage group V. This genetic localization provides a linkage group V "landmark" with which to localize other cloned sequences by in situ hybridization.Key words: Caenorhabditis elegans, 5S rRNA gene cluster, restriction fragment length difference, genetic mapping.

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