The Nature of Extraversion: A Genetical Analysis

Abstract The mitochondrial rotenone-sensitive NADH:ubiquinone oxidoreductase (complex I) comprises more than 30 subunits, the majority of which are encoded by the nucleus. In Chlamydomonas reinhardtii, only five components of complex I are coded for by mitochondrial genes. Three mutants deprived of complex I activity and displaying slow growth in the dark were isolated after mutagenic treatment with acriflavine. A genetical analysis demonstrated that two mutations (dum20 and dum25) affect the mitochondrial genome whereas the third mutation (dn26) is of nuclear origin. Recombinational analyses showed that dum20 and dum25 are closely linked on the genetic map of the mitochondrial genome and could affect the nd1 gene. A sequencing analysis confirmed this conclusion: dum20 is a deletion of one T at codon 243 of nd1; dum25 corresponds to a 6-bp deletion that eliminates two amino acids located in a very conserved hydrophilic segment of the protein.

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Genetic analysis of a cross between two homothallic strains of Physarum polycephalum

Genetics Research ◽

10.1017/s0016672300017110 ◽

1977 ◽

Vol 29 (1) ◽

pp. 55-63 ◽

Cited By ~ 7

Author(s):

R. T. M. Poulter ◽

N. K. Honey

Keyword(s):

Genetic Analysis ◽

Physarum Polycephalum ◽

Developmental Genetics ◽

Marker Genes ◽

Recombination Analysis ◽

Genetical Analysis ◽

Developmental Mutants ◽

Potential Use

SUMMARYThe homothallic amoebal clones of Physarum polycephalum are of potential use in understanding the developmental genetics of this organism. Such an application requires that complementation and recombination analysis be possible between pairs of homothallic clones. This paper is a report of the formation of mixed plasmodia by pairs of homothallic amoebal clones. In order to detect such mixed plasmodia use was made of two marker genes involved in plasmodial fusion, fusA and fusB. Sporulation of a mixed plasmodium formed from two homothallic (delayed) amoebal clones yielded progeny amoebae which were genetically recombinant. It is deduced from the ratios of various genotypes in these progeny clones that the mixed plasmodium was diploid and that meiosis was associated with sporulation. There is therefore no impediment to the use of the homothallic strains for genetical analysis. The progeny amoebal clones were observed to be showing segregation for the characters homothallic (rapid) and homothallic (delayed). This observation, taken together with other related observations, suggests that the homothallic (delayed) character is produced by mutation of the homothallic (rapid) character. The rare plasmodia formed by a homothallic (delayed) amoebal clone are the result of reversion of this mutation. Amoebal clones of the homothallic (delayed) type are therefore developmental mutants unable to perform the differentiation from amoeba to plasmodium.

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Uptake of Galactose and Lactose by Kluyveromyces lactis: Biochemical Characteristics and Attempted Genetical Analysis

Microbiology ◽

10.1099/00221287-133-1-15 ◽

1987 ◽

Vol 133 (1) ◽

pp. 15-23 ◽

Cited By ~ 3

Author(s):

H. Boze ◽

G. Moulin ◽

P. Galzy

Keyword(s):

Kluyveromyces Lactis ◽

Genetical Analysis ◽

Biochemical Characteristics

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The genetical analysis of covariance structure

Heredity ◽

10.1038/hdy.1977.9 ◽

1977 ◽

Vol 38 (1) ◽

pp. 79-95 ◽

Cited By ~ 291

Author(s):

N G Martin ◽

L J Eaves

Keyword(s):

Covariance Structure ◽

Analysis Of Covariance ◽

Genetical Analysis

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The inheritance of shank colour in single comb White Leghorn and Australorp fowls

Australian Journal of Agricultural Research ◽

10.1071/ar9510494 ◽

1951 ◽

Vol 2 (4) ◽

pp. 494

Author(s):

F Skaller ◽

GW Grigg

Keyword(s):

White Leghorn ◽

Genetical Analysis ◽

Different Types ◽

White Leghorns ◽

Single Comb ◽

Mode Of Inheritance

Evidence has been presented in the literature on the mode of inheritance of shank colour in various breeds of chickens, but little has hitherto been known about the same aspect in an Australian breed, the Black Australorp. Observations on the incidence of shank colour in different types of crosses between yellow-shanked White Leghorns and black-shanked Australorps are reported in this paper. According to the observations made by other workers on White Leghorn and other breeds, a hypothesis is advanced regarding the genes involved in determining shank colour in the White Leghorn and Australorp. A genetical analysis of the observations made by the authors on 847 single crosses, 71 backcrosses, and 31 zig-zag crosses is presented and shows close statistical agreement with the hypothesis. A genetical formula, including four autosomal and two sex-linked genes, is suggested which would explain the mode of inheritance of shank colour in White Leghorns and Australorps.

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