FlyBase:Balancer/Genotype variant Report
Last Updated: 11th December 2017
The Balancer/Genotype Variant Report contains the information for an individual balancer/genotype variant. Genotype variants are chromosomal rearrangements which carry the same rearrangement as their parent aberration (listed in the Parent aberration field of the report), but they differ genetically from the parent aberration, e.g. carrying a different constellation of alleles and/or transposable element insertions.
A genotype variant chromosome may also be a Balancer, which is a multiply inverted chromosome that suppresses recombination with the homologous chromosome. This allows the homologous chromosome (or part of it) to be maintained intact in a cross or stock. Balancers also typically carry a dominant marker and are often lethal or sterile when homozygous. This can increase their usefulness to researchers.
If an individual genotype variant chromosome has been reported to be usable as a balancer this is indicated by the presence of the Described as Balancer field in the Report.
This is a field-by-field guide to the information provided in the Balancer/Genotype Variant Report. FlyBase attributes data to the publication that reported it, so that users can easily refer back to the original publication if they wish. Thus, where possible in the fields below, the publication(s) that are the source of the information are listed, typically in parentheses to the right of the data. The exception in the Genotype Variant/Balancer Report is the General Information section which contains a summary of the identity of the genotype variant/balancer.
General Information
| Symbol | The valid symbol that is used in FlyBase for the balancer/genotype variant.
- The first part of the symbol (before the '\') is the standard prefix for the species (from the Species Abbreviations list). For species other than D.melanogaster, the species prefix is displayed wherever the balancer/genotype variant symbol is used throughout FlyBase. For D.melanogaster balancer/genotype variants, the species prefix is only displayed in the General Information section at the top of a Report. |
| Species | The organism that the balancer/genotype variant originates from, with the initial letter of the genus and the full species name listed. |
| FlyBase ID | The Primary FlyBase identifier number of the balancer/genotype variant, used to uniquely identify the balancer/genotype variant in the database.
A balancer/genotype variant may also have any number of Secondary FlyBase identifier numbers, which are listed in the Secondary FlyBase IDs section of the Balancer/Genotype Variant Report. |
| Short Genotype | This combines the symbol of a classical balancer with new allele, aberration or transposable element insertion symbols to define a unique balancer variant. |
| Parent Aberration | The parent aberration of the balancer/genotype variant. The balancer/genotype variant carries the same rearrangement as the parent aberration, but differs genetically, e.g. carrying a different constellation of alleles and/or transposable element insertions. |
| Parent Cytology | A description of the new cytological order of the parent aberration (by definition the same as that of the balancer/genotype variant).
The sequence of each chromosome involved in the chromosomal aberration is specified from one end to the other according to salivary gland chromosome band terminology. Each chromosome is separated by a semicolon. Points of breakage and reunion are indicated by vertical bars, and segments between these points are designated by the most extreme band known to be present at each end, separated by a dash. If the order of a particular segment is not known, the segment is included within parentheses, and hierarchies of ambiguities are represented by parentheses within parentheses. |
| Progenitor | The mutant chromosome on which the balancer/genotype variant was induced. This is either a chromosomal aberration or another balancer/genotype variant. |
| Described as Balancer | This field is only displayed on an individual report if the genotype variant chromosome has been reported as being usable as a balancer. The publication(s) that reported this information are listed, where available. |
| Alleles | Allele(s) that are carried on the balancer/genotype variant.
Clicking on an allele symbol will take you to the relevant Allele Report. |
| Transposon Insertions | Insertion(s) (of transgenic constructs or natural transposons) that are carried on the balancer/genotype variant.
Clicking on an insertion symbol will take you to the relevant Insertion Report. |
| Discoverer | The individual(s) who first identified or generated the balancer/genotype variant. |
Stocks
A list of the stocks from the public Stock Centers that contain this balancer/genotype variant; for each Stock Center, stock number and genotype are displayed. Clicking on the genotype will take you to the appropriate Stock Report. If there are a large number of stocks, the list on the page may be truncated, but clicking on the "More stocks available..." link will take you to a hit list of all available stocks containing the balancer/genotype variant.
Genetic Data
| Genes subject to position-effect variegation | Gene(s) that show recessive position effect variegation in the presence of the balancer/genotype variant.
Clicking on a gene symbol will take you to the relevant Gene Report. This field is only displayed in an individual Balancer/Genotype Variant Report if it contains data. |
| Genes showing dominant position-effect variegation | Gene(s) that show dominant position effect variegation in the presence of the balancer/genotype variant.
Clicking on a gene symbol will take you to the relevant Gene Report. This field is only displayed in an individual Balancer/Genotype Variant Report if it contains data. |
| Genes NOT subject to position effect variegation | Gene(s) that do not show position effect variegation in the presence of the balancer/genotype variant.
Clicking on a gene symbol will take you to the relevant Gene Report. This field is only displayed in an individual Balancer/Genotype Variant Report if it contains data. |
Other Information
Miscellaneous free text comments about the balancer/genotype variant.
Synonyms & Secondary IDs
Reported As
| Symbol Synonym | A list of symbols that have been used in the literature, or by FlyBase, to describe the balancer/genotype variant. |
| Name Synonym | A list of names that have been used in the literature, or by FlyBase, to describe the balancer/genotype variant. |
Secondary FlyBase IDs
A list of Secondary FlyBase identifier numbers of the balancer/genotype variant.
If a balancer/genotype variant has a secondary identifier number, it generally indicates that at some point it has been merged with or split from other entries in the database. See the FlyBase identifier numbers section for some examples of the cases where identifier numbers are made secondary.
References
A list of publications that discuss the balancer/genotype variant, organised by type of publication.