Fine Mapping of a Seed Protein QTL on Soybean Linkage Group I and Its Correlated Effects on Agronomic Traits

Abstract Electrophoretic variants which arise from amino acid substitutions, leading to charge differences between proteins are ubiquitous and have been used extensively for genetic analysis. Less well documented are polymorphisms in the size of proteins. Here we report that a group of glycoproteins, which share a common carbohydrate epitope, vary in size in different isolates of the cellular slime mould, Dictyostelium discoideum. One of these proteins, PsA, a developmentally regulated prespore-specific surface glycoprotein, has previously been shown to exist in three size forms due to allelic variation at the pspA locus on linkage group I. In this report, a second glycoprotein, PsB, which is also prespore specific but found inside prespore cells, is studied. PsB maps to linkage group II and exhibits at least four different sizes in the isolates examined. We propose that the size polymorphisms are the product of allelic variation at the pspB locus, due to differences in the number of repeat units.

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Linkage Analysis of Sex Determination in Bracon sp. Near hebetor (Hymenoptera: Braconidae)

Genetics ◽

10.1093/genetics/154.1.205 ◽

2000 ◽

Vol 154 (1) ◽

pp. 205-212

Author(s):

Alisha K Holloway ◽

Michael R Strand ◽

William C Black ◽

Michael F Antolin

Keyword(s):

Linkage Group ◽

Sex Determination ◽

Rapd Markers ◽

Random Amplified Polymorphic Dna ◽

Parasitic Wasp ◽

Specific Pattern ◽

Diploid Males ◽

Phenotypic Marker ◽

Group I ◽

Sex Locus

Abstract To test whether sex determination in the parasitic wasp Bracon sp. near hebetor (Hymenoptera: Braconidae) is based upon a single locus or multiple loci, a linkage map was constructed using random amplified polymorphic DNA (RAPD) markers. The map includes 71 RAPD markers and one phenotypic marker, blonde. Sex was scored in a manner consistent with segregation of a single “sex locus” under complementary sex determination (CSD), which is common in haplodiploid Hymenoptera. Under haplodiploidy, males arise from unfertilized haploid eggs and females develop from fertilized diploid eggs. With CSD, females are heterozygous at the sex locus; diploids that are homozygous at the sex locus become diploid males, which are usually inviable or sterile. Ten linkage groups were formed at a minimum LOD of 3.0, with one small linkage group that included the sex locus. To locate other putative quantitative trait loci (QTL) for sex determination, sex was also treated as a binary threshold character. Several QTL were found after conducting permutation tests on the data, including one on linkage group I that corresponds to the major sex locus. One other QTL of smaller effect had a segregation pattern opposite to that expected under CSD, while another putative QTL showed a female-specific pattern consistent with either a sex-differentiating gene or a sex-specific deleterious mutation. Comparisons are made between this study and the indepth studies on sex determination and sex differentiation in the closely related B. hebetor.

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Linkage group I: the simultaneous estimation of recombination and interference

Cytogenetic and Genome Research ◽

10.1159/000130625 ◽

1976 ◽

Vol 16 (1-5) ◽

pp. 335-339 ◽

Cited By ~ 1

Author(s):

D.A. Meyers ◽

P.M. Conneally ◽

E.W. Lovrien ◽

E. Magenis ◽

A.D. Merritt ◽

...

Keyword(s):

Linkage Group ◽

Simultaneous Estimation ◽

Group I

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DOMINANT-AND-RECESSIVE EPISTASIS IN A HOMEOTIC MOSQUITO MUTANT

Canadian Journal of Genetics and Cytology ◽

10.1139/g76-072 ◽

1976 ◽

Vol 18 (4) ◽

pp. 593-600

Author(s):

Satish C. Bhalla

Keyword(s):

Linkage Group ◽

Wild Type ◽

Pure Strain ◽

Group Iii ◽

Homeotic Mutant ◽

Culex Pipiens Fatigans ◽

Group I ◽

Ratio Data ◽

Independent Segregation ◽

Selection For

Folowing selection for 15 generations a pure strain of a homeotic mutant spur was isolated from a Brazilian population of the mosquito Culex pipiens fatigans. Monohybrid crosses showed a 13:3 segregation indicating dominant-and-recessive epistasis for wild-type vs. spur. This implies that a dominant allele at one locus and a recessive at the other interact to produce the mutant phenotype. Dihybrid crosses with linkage group II markers yellow and ruby gave 39:13:9:3 ratios indicating independent segregation. However, the dihybrid cross with linkage group I marker maroon showed a highly significant departure from 39:13:9:3 ratio. Data available indicate that the phenotype spur is controlled by a dominant epistat in linkage group III and a recessive epistat (approximately 31.9 crossover units from maroon) in linkage group I.

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