FB2025_05 , released December 11, 2025
FB2025_05 , released December 11, 2025
CV Term Report
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General Information
Term testis ID (Ontology) FBbt:00004928 (Fly Anatomy)
Definition Tube of the male reproductive system connected to the seminal vesicle at the basal end. It is a tube 1.9mm long and 90-100 micrometers in diameter, with the basal half helically coiled and the distal half forming a freely extended arc. The coiled portion is spirally wound twice around a center occupied by the testicular duct and the distal portion of the seminal vesicle. The wall of the testis consists of two very thin layers containing widely spaced nuclei: an inner sheath and an outer sheath composed of small flattened polygonal cells that contain yellow pigment granules. The development of germline cells takes place in the testis.[ FlyBase:FBrf0007735 FlyBase:FBrf0033532 ]
Comment
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Annotations
Records annotated with this term OR any of its CHILD TERMS
Records annotated with this exact term (annotations to child terms are NOT included)
Data Class Field Records
Alleles (FBal)  PHENOTYPE_MANIFEST_IN     573
Insertions (FBti)  EXPRESSION_STAGE_TISSUE_POSITION      91
Insertions (FBti)  PHENOTYPE_MANIFEST_IN     167
Constructs (FBtp)  PHENOTYPE_MANIFEST_IN     170
show Full annotation statements including this term (annotations to child terms are NOT included), and relevant FlyBase records
 Full annotation statements 
Relevant FlyBase reports
 Alleles Genes Images Insertions Constructs
 testis (all annotations which use CV term, excluding "NOT" statements)     578    352      6    257    222
     testis | adult stage      71       --       --      16     36
     testis | adult stage | cell non-autonomous | somatic clone       3       --       --       2       --
     testis | adult stage | clone of cells       1       --       --       1       --
     testis | adult stage | germline clone       2       --       --       2       --
     testis | adult stage | progressive       3       --       --       --       1
     testis | germline clone       9       --       --       2      4
     testis | heat sensitive       9       --       --       1       --
     testis | larval stage       5       --       --       1       --
     testis | maternal effect       3       --       --       2       --
     testis | progressive       2       --       --       1       --
     testis | progressive | temperature conditional       1       --       --       --       --
     testis | pupal stage       1       --       --       --       --
     testis | RU486 conditional       2       --       --       --       2
     testis | second instar larval stage       1       --       --       1       --
     testis | somatic clone       8       --       --       1      5
     testis | somatic clone - tissue specific       1       --       --       1       --
     testis | temperature conditional       3       --       --       --       1
     testis | third instar larval stage       5       --       --       3       --
Spanning Tree (Parents/Children)
Only view relationship:
organism
 |__adult____________________________
reproductive system                  |
 |__gonad____________________________|
 |__male reproductive system_________|
male organism                        |
 |__male-specific anatomical entity__|
male-specific anatomical entity      |
 |__male reproductive system_________|
multicellular structure              |
 |__gonad____________________________|
anatomical entity                    |
 |__male-specific anatomical entity__|
                                     testis  4871 rec.
                                      |__germinal proliferation center 712 rec.
                                      |   |__cyst progenitor cell 252 rec.
                                      |   |__germinal proliferation center hub(+) 233 rec.
                                      |   |__male germline stem cell 430 rec.
                                      |__male fusome 61 rec.
                                      |   |__spermatocyte fusome 28 rec.
                                      |__male germline cyst 2288 rec.
                                      |   |__cyst cell of testis(+) 229 rec.
                                      |   |__spermatid cyst(+) 1189 rec.
                                      |   |__spermatocyte cyst(+) 1000 rec.
                                      |   |__spermatogonial cyst(+) 419 rec.
                                      |__somatic cell of testis 705 rec.
                                      |   |__cyst cell of testis(+) 229 rec.
                                      |   |__cyst progenitor cell 252 rec.
                                      |   |__hub cell 200 rec.
                                      |   |__testis sheath epithelial cell(+) 122 rec.
                                      |   |__testis sheath muscle cell 33 rec.
                                      |__spermatozoon 1803 rec.
                                      |__testis sheath 174 rec.
                                      |   |__terminal epithelium of testis(+) 15 rec.
                                      |   |__testis sheath epithelial cell(+) 122 rec.
                                      |   |__testis sheath muscle cell 33 rec.
                                      |__waste bag 94 rec.
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Is a gonad
male-specific anatomical entity
Develops from larval testis
Part of adult
male reproductive system
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Synonyms
Secondary IDs
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UBERON:0000473