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General Information
Symbol
Dp(1;f)J21A
Species
D. melanogaster
Name
FlyBase ID
FBab0024065
Feature type
Also Known As
J21A
Computed Breakpoints include
Sequence coordinates
Member of large scale dataset(s)
Nature of Aberration
Cytological Order
Class of aberration (relative to wild type)
Class of aberration (relative to progenitor)
Breakpoints
Causes alleles
Carries alleles
Transposon Insertions
Formalized genetic data
Genetic mapping information
Comments
Comments on Cytology

Used in experiments that showed that efficient achiasmate homolog disjunction in female meiosis I requires 1000kb of overlap in the centric heterochromatin and is not affected by homologous euchromatin or overall size differences. Disjunction efficiency decreases linearly as heterochromatic overlap is reduced from 1000 to 430kb. Rescue experiments with nod transgenes showed that heterochromatin does not act solely to promote chromosome movement or spindle attachment. Centric heterochromatin seems to contain multiple pairing elements that act additively to initiate or maintain the proper alignment of achiasmate chromosomes in meiosis I.

"Terminal" deletion.

Sequence Crossreferences
DNA sequence
Protein sequence
Gene Deletion and Duplication Data
Genes Deleted / Disrupted
Complementation Data
Completely deleted / disrupted
Partially deleted / disrupted
Molecular Data
Completely deleted
Partially deleted
Genes NOT Deleted / Disrupted
Complementation Data
Molecular Data
 
Genes Duplicated
Complementation Data
Completely duplicated
Partially duplicated
Molecular Data
Completely duplicated
Partially duplicated
Genes NOT Duplicated
Complementation Data
 
Molecular Data
 
Phenotypic Data
In combination with other aberrations

Transmission rate through females to progeny is 28% in the first 5 days of egg lay. SM1, TM3 and FM7c balancer chromosomes have no effect on transmission. FM7a-nod4 balancer chromosome causes a mild reduction in transmission. Heterozygous deficiencies can have strong effects on the transmission of the chromosome.

NOT in combination with other aberrations

Exhibits moderate instability in a monosome transmission assay; transmitted to only 27% of the progeny.

Transmission rate through females to progeny is 28% in the first 5 days of egg lay. nod, ncd and Klp3A mutations strongly decrease transmission. One or two extra copies of nod provided by P{flag-nodhsp} partially rescues transmission. mei-S332 ord double mutants amd ord mutations cause a mild reduction in transmission. Other ord and mei-S332 mutations, grau, cort, mit(1)15 or wapl mutations have no effect on transmission. rod mutations cause a mild increase in transmission.

Transmitted from meiosis at 2.6% in nod3/nod+ females and 24% in wild type females.

Stocks (0)
Notes on Origin
Discoverer
 
Balancer / Genotype Variants of the Aberration
 
Separable Components
 
Other Comments
 

Contains only 290kb of centric heterochromatin.

Acentric mini-chromosomes are lost at a moderate but elevated rate during male germline mitotic divisions and in female mitosis, but appear to be transmitted efficiently through pre-blastoderm mitoses and male meiosis. mit(1)15 can localise to the mini-chromosome. Acentric mini-chromosomes are normally inherited, transmission is achieved by a mechanism similar to normal centromere-containing chromosomes, which utilises nod and mit(1)15 and involves movement to the spindle poles. Newly generated acentric fragments from the tip of the normal X chromosome do not display neocentromere activity in male meiosis I.

Minichromosome is 580bp in length.

Monosome transmission behaviour from both male and female parents is moderately unstable, heterochromatin contains only all of Bora Bora.

Synonyms and Secondary IDs (5)
References (14)