Cytogenetic characterization of the 4BC region on the X chromosome of Drosophila melanogaster: Localization of the mei-9, norpA and omb genes

ABSTRACT An average size chromomere of the polytene X chromosome of Drosophila melanogaster contains enough DNA in each haploid equivalent strand to code for 30 genes, each 1,000 nucleotides long. We have attempted to learn about the organization of chromosomes by asking how many functional units can be localized within a chromomere. This was done by 1) recovery of mutants representative of every cistron in the 3A2-3C2 region; 2) the characterization of the function of each mutant type and grouping by complementation tests; 3) the determination of the genetic and cytological position of each cistron by recombination and deletion mapping. The data clearly show one functional group per chromomere. It is postulated that a chromomere is one cistron within which much of the DNA is regulatory in function.

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Molecular cytogenetic characterization of two Turner syndrome patients with mosaic ring X chromosome

Journal of Assisted Reproduction and Genetics ◽

10.1007/s10815-016-0761-x ◽

2016 ◽

Vol 33 (9) ◽

pp. 1161-1168 ◽

Cited By ~ 3

Author(s):

Pooja Chauhan ◽

Sushil Kumar Jaiswal ◽

Anjali Rani Lakhotia ◽

Amit Kumar Rai

Keyword(s):

Turner Syndrome ◽

X Chromosome ◽

Molecular Cytogenetic ◽

Cytogenetic Characterization

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Isolation and Cytogenetic Characterization of Male Meiotic Mutants of Drosophila melanogaster

Genetics ◽

10.1093/genetics/166.4.1795 ◽

2004 ◽

Vol 166 (4) ◽

pp. 1795-1806

Author(s):

Kazuyuki Hirai ◽

Satomi Toyohira ◽

Takashi Ohsako ◽

Masa-Toshi Yamamoto

Keyword(s):

Drosophila Melanogaster ◽

Sex Chromosome ◽

Male Meiosis ◽

Fourth Chromosome ◽

Homologous Chromosomes ◽

Meiotic Mutants ◽

Chromatid Cohesion ◽

Cytogenetic Characterization ◽

Meiosis I

Abstract Proper segregation of homologous chromosomes in meiosis I is ensured by pairing of homologs and maintenance of sister chromatid cohesion. In male Drosophila melanogaster, meiosis is achiasmatic and homologs pair at limited chromosome regions called pairing sites. We screened for male meiotic mutants to identify genes required for normal pairing and disjunction of homologs. Nondisjunction of the sex and the fourth chromosomes in male meiosis was scored as a mutant phenotype. We screened 2306 mutagenized and 226 natural population-derived second and third chromosomes and obtained seven mutants representing different loci on the second chromosome and one on the third. Five mutants showed relatively mild effects (<10% nondisjunction). mei(2)yh149 and mei(2)yoh7134 affected both the sex and the fourth chromosomes, mei(2)yh217 produced possible sex chromosome-specific nondisjunction, and mei(2)yh15 and mei(2)yh137 produced fourth chromosome-specific nondisjunction. mei(2)yh137 was allelic to the teflon gene required for autosomal pairing. Three mutants exhibited severe defects, producing >10% nondisjunction of the sex and/or the fourth chromosomes. mei(2)ys91 (a new allele of the orientation disruptor gene) and mei(3)M20 induced precocious separation of sister chromatids as early as prometaphase I. mei(2)yh92 predominantly induced nondisjunction at meiosis I that appeared to be the consequence of failure of the separation of paired homologous chromosomes.

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MICROCLONING AND CHARACTERIZATION OF THE EARLY ECDYSONE PUFF REGION 2B OF THE X CHROMOSOME OF DROSOPHILA MELANOGASTER

Ecdysone ◽

10.1016/b978-0-08-032016-8.50037-4 ◽

1986 ◽

pp. 249-254

Author(s):

JOAN GALCERÁN ◽

CONRADO GIMÉNEZ ◽

JAN ERIK EDSTRÖM ◽

MARTA IZQUIERDO

Keyword(s):

Drosophila Melanogaster ◽

X Chromosome

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Cloning and characterization of a dispersed, multicopy, X chromosome sequence in Drosophila melanogaster.

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.84.9.2843 ◽

1987 ◽

Vol 84 (9) ◽

pp. 2843-2847 ◽

Cited By ~ 30

Author(s):

G. L. Waring ◽

J. C. Pollack

Keyword(s):

Drosophila Melanogaster ◽

X Chromosome ◽

Chromosome Sequence

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Isolation and Cytogenetic Characterization of Male Meiotic Mutants of Drosophila melanogaster

Genetics ◽

10.1534/genetics.166.4.1795 ◽

2004 ◽

Vol 166 (4) ◽

pp. 1795-1806 ◽

Cited By ~ 8

Author(s):

K. Hirai

Keyword(s):

Drosophila Melanogaster ◽

Meiotic Mutants ◽

Cytogenetic Characterization

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BEHAVIORAL MUTANTS OF DROSOPHILA MELANOGASTER. I. ISOLATION AND MAPPING OF MUTATIONS WHICH DECREASE FLIGHT ABILITY

Genetics ◽

10.1093/genetics/87.1.95 ◽

1977 ◽

Vol 87 (1) ◽

pp. 95-104

Author(s):

Theodore Homyk ◽

David E Sheppard

Keyword(s):

Drosophila Melanogaster ◽

Genetic Mapping ◽

X Chromosome ◽

Flight Test ◽

Flight Behavior ◽

Temperature Sensitive ◽

Flight Ability ◽

Initial Characterization ◽

F1 Progeny

ABSTRACT A flight test box was developed and used in the isolation and initial characterization of Drosophila melanogaster mutants defective in flight behavior. Forty-eight mutants were isolated from F1 progeny of ethyl methanesulfonate-treated males. Genetic mapping and complementation tests show that the mutations reside at thirty-four different sites on the X chromosome. Different mutants show different degrees of flight ability compared to controls. Forty-six mutations are recessive, while two appear to be semi-dominant with respect to flight behavior. In addition to flight defects, five mutants have visible defects, five behave as temperature-sensitive lethals and three exhibit abnormal electro-retinograms. Alleles of each of the previously known behavioral mutations, Hyperkinetic, ether à go-go and Shaker were found. Preliminary studies also suggest that the flight behavioral phenotype of mutations at seven sites is affected by the temperature at which the flies develop.

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ISOLATION AND CHARACTERIZATION OF X-LINKED MUTANTS OF DROSOPHILA MELANOGASTER WHICH ARE SENSITIVE TO MUTAGENS

Genetics ◽

10.1093/genetics/84.3.485 ◽

1976 ◽

Vol 84 (3) ◽

pp. 485-506

Author(s):

J B Boyd ◽

M D Golino ◽

T D Nguyen ◽

M M Green

Keyword(s):

Drosophila Melanogaster ◽

Functional Groups ◽

X Chromosome ◽

Nitrogen Mustard ◽

Methyl Methanesulfonate ◽

Isolation And Characterization ◽

Post Replication Repair ◽

Complementation Groups ◽

High Concentrations

ABSTRACT Thirteen X-linked mutants have been isolated in Drosophila melanogaster which render male and homozygous female larvae sensitive to the mutagen methyl methanesulfonate. Their characterization and preliminary assignment to functional groups is described. Four of these mutants are alleles of mei-41 (Baker and Carpenter 1972). Like previously isolated alleles of this locus, these mutants reduce fertility and increase loss and nondisjunction of the X-chromosome in homozygous females. The remaining mutants have been tentatively assigned to six functional groups (two mutants to the mus(1)101 locus, two to mus(1)102, two to mus(1)103, and one each to mus(1)104, mus(1)105, and mus(1)106). Several of the complementation groups can be distinguished on the basis of nondisjunction and cross sensitivity to mutagens. Females homozygous for the mei-41, mus(1)101 and mus(1)102 mutants exhibit elevated levels of nondisjunction. Mutants belonging to complementation groups mei-41, mus(1)101, and mus(1)104 are sensitive to nitrogen mustard (HN2) in addition to their MMS sensitivity. Among these mutants there is currently a direct correlation between sensitivity to HN2, sensitivity to 2-acetylaminofluorene and a deficiency in post-replication repair (Boyd and Setlow 1976). Only the mei-41 mutants are hypersensitive to UV radiation, although several of the mutants exhibit sensitivity to Y-rays. Semidominance is observed in female larvae of the mei-41, mus(1)104, and mus(1)103 mutants after exposure to high concentrations of MMS. The properties of the mutants generally conform to a pattern which has been established for related mutants in yeast. Additional properties of these mutants are summarized in Table 9.

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