Genetics of Gracilaria tikvahiae (Rhodophyceae). VI. Complementation and linkage analysis of pigmentation mutants

1979 ◽  
Vol 57 (1) ◽  
pp. 64-68 ◽  
Author(s):  
John P. van der Meer
Keyword(s):  
Linkage Analysis ◽  
Linkage Map ◽  
Intragenic Recombination ◽  
Wild Type ◽  
Multiple Alleles ◽  
Gracilaria Tikvahiae

Pigmentation mutants of Gracilaria tikvahiae that differed in several ways from the brownish colour of wild type were characterized genetically by complementation and recombination. Thirty cistrons with multiple alleles at several loci were identified. Many of the cistrons were genetically linked with one or more other loci, and the beginnings of a linkage map is presented. Examples of intragenic recombination between noncomplementing mutants were also encountered.

Integration of molecular and classical linkage groups of the silkworm, Bombyx mori (n = 28)

Genome ◽  
2005 ◽  
Vol 48 (4) ◽  
pp. 626-629 ◽  
Author(s):  
Yuji Yasukochi ◽  
Yutaka Banno ◽  
Kohji Yamamoto ◽  
Marian R Goldsmith ◽  
Hiroshi Fujii
Keyword(s):  
Molecular Markers ◽  
Linkage Group ◽  
Linkage Analysis ◽  
Linkage Map ◽  
Bombyx Mori ◽  
Linkage Maps ◽  
Wild Type ◽  
Linkage Groups ◽  
Sequence Tagged Sites ◽  
Silkworm Bombyx Mori

Previously published linkage groups (LGs) composed of molecular markers were assigned to classical LGs in the silkworm, Bombyx mori (n = 28). Four markers from the classical linkage map, og, w-1, Lp, and Pfl, were assigned to the molecular linkage maps using sequence tagged sites. In addition, linkage analysis was carried out using BF1 progeny between wild-type and mutant stocks carrying morphological phenotypic markers. As a result, the counterparts for 26 of 28 molecular LGs were identified with their counterparts of the classical LGs. Two visible markers, Sel and Xan, representing different classical LGs, were found to be linked.Key words: Bombyx mori, classical linkage group (LG), PCR-based genotyping, mutant, STS.

A genetic study on Gracilaria sjoestedtii

1988 ◽  
Vol 66 (10) ◽  
pp. 2022-2026 ◽  
Author(s):  
Xuecheng Zhang ◽  
John P. van der Meer
Keyword(s):  
Chromosome Number ◽  
Genetic Study ◽  
Maternal Inheritance ◽  
Intragenic Recombination ◽  
Wild Type ◽  
Multiple Alleles ◽  
Wild Type Clone ◽  
Nuclear Mutations ◽  
Diploid Gametes ◽  
Mendelian Analysis

In the present study on Gracilaria sjoestedtii, 41 mutants (40 pigmentation and 1 morphological) were isolated. These were characterized in a Mendelian analysis, which showed that 26 of the pigmentation variants are recessive nuclear mutations. The remaining 14 are cytoplasmic mutants having maternal inheritance and no detectable transmission through spermatia. A partial complementation analysis identified seven cistrons among the nuclear pigmentation mutants. Multiple alleles were encountered at five loci and apparent intragenic recombination was observed. No linkage between cistrons was found in recombination tests conducted thus far. Mitotic recombination leading to diploid gametes on tetrasporophytes was observed and used to construct triploid tetrasporophytes. The chromosome number of a wild-type clone of G. sjoestedtii was determined at meiosis as n = 29–30. Trivalent chromosomes were observed during meiosis in tetrasporophytes obtained by crossing female plants with tetrasporophytes. In culture tanks with flowing seawater, female gametophytes grew faster and appeared more suitable for vegetative propagation than male gametophytes and tetrasporophytes.

scholarly journals Assigning Linkage Haplotypes From Parent and Progeny Genotypes

Genetics ◽  
1996 ◽  
Vol 142 (4) ◽  
pp. 1363-1367
Author(s):  
Ardeshir Nejati-Javaremi ◽  
Charles Smith
Keyword(s):  
Linkage Analysis ◽  
Linkage Map ◽  
Inbred Lines ◽  
Crossover Point ◽  
Multiple Alleles ◽  
Allele Type ◽  
Sib Families ◽  
Experimental Crosses

Abstract Given the genotypes of parents and progeny, their haplotypes over several or many linked loci can be easily assigned by listing the allele type at each locus along the haplotype known to be from each parent. Only a small number (5-10) of progeny per family is usually needed to assign the parental and progeny haplotypes. Any gaps left in the haplotypes may be filled in from the assigned haplotypes of relatives. The process is facilitated by having multiple alleles at the loci and by using more linked loci in the haplotype and with more progeny from the mating. Crossover haplotypes in the progeny can be identified by their being unique or uncommon, and the crossover point can often be detected if the locus linkage map order is known. The haplotyping method applies to outbreeding populations in plants, animals and man, as well as to traditional experimental crosses of inbred lines. The method also applies to half-sib families, whether the genotypes of the mates are known or unknown. The haplotyping procedure is already used in linkage analysis but does not seem to have been published. It should be useful in teaching and in genetic applications of haplotypes.

scholarly journals Centromere-Linkage Analysis and Consolidation of the Zebrafish Genetic Map

Genetics ◽  
1996 ◽  
Vol 142 (4) ◽  
pp. 1277-1288
Author(s):  
Stephen L Johnson ◽  
Michael A Gates ◽  
Michele Johnson ◽  
William S Talbot ◽  
Sally Horne ◽  
...  
Keyword(s):  
Linkage Group ◽  
Linkage Analysis ◽  
Genetic Analysis ◽  
Linkage Map ◽  
Rapid Method ◽  
Genetic Map ◽  
Dna Polymorphisms ◽  
Linkage Groups

Abstract The ease of isolating mutations in zebrafish will contribute to an understanding of a variety of processes common to all vertebrates. To facilitate genetic analysis of such mutations, we have identified DNA polymorphisms closely linked to each of the 25 centromeres of zebrafish, placed centromeres on the linkage map, increased the number of mapped PCR-based markers to 652, and consolidated the number of linkage groups to the number of chromosomes. This work makes possible centromere-linkage analysis, a novel, rapid method to assign mutations to a specific linkage group using half-tetrads.

scholarly journals Linkage Analysis of Nine Isozyme Genes on the Conventional Linkage Map in Rice.

1991 ◽  
Vol 41 (2) ◽  
pp. 265-272 ◽  
Author(s):  
Ryuji ISHIKAWA ◽  
Hiroko MORISHIMA ◽  
Toshiro KINOHSITA ◽  
Takeo HARADA ◽  
Minoru NIIZEKI ◽  
...  
Keyword(s):  
Linkage Analysis ◽  
Linkage Map

ON THE IDENTIFICATION OF THE ROSY LOCUS DNA IN DROSOPHILA MELANOGASTER: INTRAGENIC RECOMBINATION MAPPING OF MUTATIONS ASSOCIATED WITH INSERTIONS AND DELETIONS

Genetics ◽  
1986 ◽  
Vol 112 (4) ◽  
pp. 755-767
Author(s):  
S H Clark ◽  
M McCarron ◽  
C Love ◽  
A Chovnick
Keyword(s):  
Drosophila Melanogaster ◽  
Large Scale ◽  
Conclusive Evidence ◽  
Hybrid Dysgenesis ◽  
Intragenic Recombination ◽  
Wild Type ◽  
Structural Element ◽  
Insertions And Deletions ◽  
Recombination Mapping

ABSTRACT DNA extracts of several rosy-mutation-bearing strains were associated with large insertions and deletions in a defined region of the molecular map believed to include the rosy locus DNA. Large-scale, intragenic mapping experiments were carried out that localized these mutations within the boundaries of the previously defined rosy locus structural element. Molecular characterization of the wild-type recombinants provides conclusive evidence that the rosy locus DNA is localized to the DNA segment marked by these lesions.—One of the mutations, ry  2101, arose from a P-M hybrid dysgenesis experiment and is associated with a copia insertion. Experiments are described which suggest that copia mobilizes in response to P-M hybrid dysgenesis.—Relevance of the data to recombination in higher organisms is considered.

Effects of temperature and tissue age on gel strength and composition of agar from Gracilaria tikvahiae (Rhodophyceae)

1984 ◽  
Vol 62 (8) ◽  
pp. 1665-1670 ◽  
Author(s):  
James S. Craigie ◽  
Zong C. Wen
Keyword(s):  
Gel Strength ◽  
Wild Type ◽  
Gracilaria Tikvahiae ◽  
Morphological Mutants ◽  
Wild Type Clone ◽  
Effects Of Temperature ◽  
Lateral Branches ◽  
Increasing Temperature ◽  
Strong Inverse Relationship ◽  
Galactose Content

Agars were prepared from a wild type and two morphological mutants of Gracilaria tikvahiae grown at 17, 22, and 27 °C, and from apical segments, main axis segments, and lateral branches of the wild type clone MP-2 grown at 17 and 27 °C. The yield of native agar was 9–11% from the young parts and 19–23% from the most mature parts of the MP-2 thallus. The gel strengths of alkali-modified agars showed a strong inverse relationship with increasing temperature of growth in each of the three clones examined. The modified agar produced from plants grown at high temperature contained more sulfate and less 3,6-anhydro-L-galactose than agars produced at lower temperatures. The increase in 4-O-methyl-L-galactose content of the agars as the growth temperature increased was especially marked. Dissection experiments on clone MP-2 showed that agar with the maximum gel strength and 3,6-anhydro-L-galactose content and the minimum sulfate and 4-O-methyl-L-galactose content was produced at low temperature by apical segments and young lateral branches. The poorest quality agar was prepared from mature segments of the thallus, especially those grown at high temperatures. Agars prepared from mature parts of the thallus were greatly enriched in 4-O-methyl-L-galactose, which reached 8.8% of the weight of the agar at 27 °C. Changes in 6-O-methyl-D-galactose were smaller, but this sugar was lowest in agar prepared from young tissues of plants grown at 17 °C.

Growth experiments on morphological mutants of Gracilaria tikvahiae (Rhodophyceae)

1983 ◽  
Vol 61 (6) ◽  
pp. 1654-1659 ◽  
Author(s):  
Mohsin U. Patwary ◽  
John P. van der Meer
Keyword(s):  
Growth Rate ◽  
High Density ◽  
Low Density ◽  
Wild Type ◽  
Gracilaria Tikvahiae ◽  
Morphological Mutants ◽  
Growth Experiments

The growth of morphological mutants of Gracilaria tikvahiae was compared with that of wild-type clones in tanks of flowing seawater in a greenhouse. At low density four mutants grew faster than a related wild type, and two, MP-40 and MP-44, grew faster than any of the wild clones tested. Of the mutants, MP-40 consistently had the fastest growth rate at low density. At high density MP-40 and MP-44 again grew faster than wild type; however, MP-44 had the faster growth rate and gave the higher yields. Both of these mutants removed nitrogen (NH4+) from seawater faster than the wild types and both proved to be much more epiphyte resistant, with MP-40 scoring highest for both of these characteristics.

scholarly journals O-acetylation controls the glycosylation of bacterial serine-rich repeat glycoproteins.

2020 ◽  
pp. jbc.RA120.016116
Author(s):  
Ravin Seepersaud ◽  
Alexander C. Anderson ◽  
Barbara A. Bensing ◽  
Biswa P Choudhury ◽  
Anthony J. Clarke ◽  
...  
Keyword(s):  
Linkage Analysis ◽  
Regulatory Mechanism ◽  
Human Platelets ◽  
Bacterial Virulence ◽  
Wild Type ◽  
Post Translational Modification ◽  
Gram Positive Bacteria ◽  
Wide Range ◽  
Platelet Binding

The serine-rich repeat (SRR) glycoproteins of Gram-positive bacteria are a family of adhesins that bind to a wide range of host ligands, and expression of SRR glycoproteins is linked with enhanced bacterial virulence. The biogenesis of these surface glycoproteins involves their intracellular glycosylation and export via the accessory Sec (aSec) system. While all aSec components are required for SRR glycoprotein export, Asp2 of Streptococcus gordonii also functions as an O-acetyltransferase that modifies GlcNAc residues on the SRR adhesin GspB. Since these GlcNAc residues can also be modified by the glycosyltransferases Nss and Gly, it has been unclear whether the post-translational modification of GspB is coordinated. We now report that acetylation modulates the glycosylation of exported GspB. Loss of O-acetylation due to aps2 mutagenesis led to the export of GspB glycoforms with increased glucosylation of the GlcNAc moieties. Linkage analysis of the GspB glycan revealed that both O-acetylation and glucosylation occurred at the same C6 position on GlcNAc residues, and that O-acetylation prevented Glc deposition. Whereas streptococci expressing non-acetylated GspB with increased glucosylation were significantly reduced in their ability to bind human platelets in vitro, deletion of the glycosyltransferases nss and gly in the asp2 mutant restored platelet binding to wild-type levels. These findings demonstrate that GlcNAc O-acetylation controls GspB glycosylation, such that binding via this adhesin is optimized. Moreover, since O-acetylation has comparable effects on the glycosylation of other SRR adhesins, acetylation may represent a conserved regulatory mechanism for the post-translational modification of the SRR glycoprotein family.

RAD52-INDEPENDENT MITOTIC GENE CONVERSION IN SACCHAROMYCES CEREVISIAE FREQUENTLY RESULTS IN CHROMOSOMAL LOSS

Genetics ◽  
1985 ◽  
Vol 111 (1) ◽  
pp. 7-22
Author(s):  
James E Haber ◽  
Mark Hearn
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Conversion ◽  
Mitotic Recombination ◽  
Gene Conversion Event ◽  
Intragenic Recombination ◽  
Wild Type ◽  
Conversion Event ◽  
Chromosomal Loss ◽  
Mitotic Gene Conversion ◽  
Striking Effect

ABSTRACT We have examined spontaneous, interchromosomal mitotic recombination events between his4 alleles in both Rad+ and rad52 strains of Saccharomyces cerevisiae. In Rad+ strains, 74% of the His+ prototrophs resulted from gene conversion events without exchange of flanking markers. In diploids homozygous for the rad52-1 mutation, the frequency of His+ prototroph formation was less than 5% of the wild-type value, and more than 80% of the gene conversion events were accompanied by an exchange of flanking markers. Most of the rad52 intragenic recombination events arose by gene conversion accompanied by an exchange of flanking markers and not by a simple reciprocal exchange between the his4A and his4C alleles. There were also profound effects on the kinds of recombinant products that were recovered. The most striking effect was that RAD52-independent mitotic recombination frequently results in the loss of one of the two chromosomes participating in the gene conversion event.

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