FB2025_05 , released December 11, 2025
FB2025_05 , released December 11, 2025
CV Term Report
Help Close All Open All
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
Links to External Ontologies
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:
multicellular structure
 |__gonad____________________________
anatomical entity                    |
 |__male-specific anatomical entity__|
                                     testis  4871 rec.
Spanning Tree View Settings
Parents/Children
View Depth
Show hierarchy levels: for parents, for children
hide Relationships
Is a gonad
male-specific anatomical entity
Develops from larval testis
Part of adult
male reproductive system
hide Synonyms & Secondary IDs
Synonyms
Secondary IDs
hide External Crossreferences & Linkouts
UBERON:0000473