FB2024_04 , released June 25, 2024
Human Disease Model Report: azoospermia and testicular cancer (postulated), RBBP7-related
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General Information
Name
azoospermia and testicular cancer (postulated), RBBP7-related
FlyBase ID
FBhh0001480
Disease Ontology Term
Parent Disease
OMIM
Overview

The X-linked human gene RBBP7 has been shown to play a key role in spermatogenesis; its deficiency has been postulated to lead to inherited predisposition to non-obstructive azoospermia and to the potential development of testicular tumors. There is a single fly ortholog, Caf1-55, for which multiple genetic reagents have been generated, including loss-of-function alleles, RNAi-targeting constructs, alleles caused by insertional mutagenesis, overexpression constructs, and a CRISPR/Cas9-based LOF construct.

Initially identified in a large-scale analysis of X chromosome-linked protein-coding genes in 2,354 azoospermic/cryptozoospermic men from four independent and geographically separate cohorts, RBBP7 was found to be mutated in ten men across all cohorts. A subsequent study identified a variant of RBBP7 in two brothers with non-obstructive azoospermia; one brother also had a small testicular tumor.

UAS constructs of the human Hsap\RBBP7 gene have been introduced into flies, including a construct carrying a variant implicated in this disease. Heterologous rescue (functional complementation) is observed: wild-type human RBBP7 rescues male infertility in Caf1-55-deficient Drosophila; however, RBBP7 carrying the disease-implicated variant fails to rescue. (See the 'Disease-Implicated Variants' table, below.)

In Drosophila, animals homozygous for a null mutation of Caf1-55 typically die during the larval stage. In Drosophila males, knockdown of Caf1-55 in germ cells, using tissue-specific GAL4/UAS-RNAi, results in reduced underdeveloped testes and loss of male germline stem cells. Knockdown in the somatic cyst cells of the testis results in hyperproliferative testicular cells.

[updated Jan. 2024 by FlyBase; FBrf0222196]

Disease Summary Information
Parent Disease Summary: azoospermia, non-obstructive
Symptoms and phenotype

Non-obstructive azoospermia (NOA) is defined as absence of any measurable level of sperm in semen, resulting from a defect in the production of spermatozoa in the testes. [from MedGen, Non-obstructive azoospermia; MedGen UID: 866757]

Non-obstructive azoospermia (NOA), or failure of spermatogenesis within the testis, is diagnosed in approximately 10% of infertile men. NOA may be due to a lack of appropriate stimulation by gonadotropins, in which case hormonal therapy is usually effective. A larger category of non-obstructive azoospermia consists of men with an intrinsic testicular impairment. In these cases, the primary approach is to improve the quantity and quality of sperm retrieved from the testis for use for in vitro fertilization (Kumar, 2013; PMCID:PMC3583162).

Specific Disease Summary: azoospermia and testicular cancer (postulated), RBBP7-related
OMIM report
Human gene(s) implicated
Symptoms and phenotype

Observation of non-obstructive azoospermia (NOA).

Genetics

Locus identified in large-scale analysis of X-linked mutations in men with non-obstructive azoospermia.

Cellular phenotype and pathology
Molecular information

RBBP7 (RB binding protein 7, chromatin remodeling factor) is a core histone-binding subunit that may target chromatin remodeling factors, histone acetyltransferases and histone deacetylases to their histone substrates in a manner that is regulated by nucleosomal DNA. Component of several complexes which regulate chromatin metabolism. [from Uniprot:Q16576; 2022.11.02]

External links
Disease synonyms
azoospermia (postulated), RBBP7-related
male infertility
NOA
non-obstructive azoospermia
Search term: Leydig cell tumor
Ortholog Information
Human gene(s) in FlyBase
Human gene (HGNC)
D. melanogaster ortholog (based on DIOPT)
Comments on ortholog(s)

two to one: human gene to Drosophila gene.

Other mammalian ortholog(s) used
    D. melanogaster Gene Information (1)
    Gene Snapshot
    Chromatin assembly factor 1, p55 subunit (Caf1-55) encodes a subunit of the MuvB core complex. The MuvB core binds to the oncoprotein encoded by Myb and the Rbf-E2f2-Dp tumor suppressor complex, thereby controlling the expression of many genes, including critical regulators of the cell cycle. [Date last reviewed: 2019-03-21]
    Gene Groups / Pathways
    Comments on ortholog(s)

    High-scoring ortholog of human RBBP4 and RBBP7; (1 Drosophila to 2 human).

    Orthologs and Alignments from DRSC
    DIOPT - DRSC Integrative Ortholog Prediction Tool - Click the link below to search for orthologs in Humans
    Other Genes Used: Viral, Bacterial, Synthetic (0)
      Summary of Physical Interactions (61 groups)
      protein-protein
      Interacting group
      Assay
      References
      pull down, western blot
      anti tag coimmunoprecipitation, western blot
      anti tag coimmunoprecipitation, western blot, anti bait coimmunoprecipitation, tandem affinity purification, Identification by mass spectrometry, affinity technology, molecular weight estimation by staining
      anti tag coimmunoprecipitation, anti tag western blot
      ion exchange chromatography, anti bait coimmunoprecipitation, molecular weight estimation by staining, peptide massfingerprinting
      anti tag coimmunoprecipitation, western blot, ion exchange chromatography, anti bait coimmunoprecipitation, molecular weight estimation by staining
      anti tag coimmunoprecipitation, Identification by mass spectrometry
      tandem affinity purification, molecular weight estimation by coomasie staining, Identification by mass spectrometry, anti tag coimmunoprecipitation, western blot, peptide massfingerprinting, cross-linking study, pull down, autoradiography, anti tag western blot
      anti tag coimmunoprecipitation, anti bait coimmunoprecipitation, western blot
      anti tag coimmunoprecipitation, anti bait coimmunoprecipitation, western blot
      anti bait coimmunoprecipitation, western blot
      ion exchange chromatography, cosedimentation, molecular weight estimation by staining, anti tag coimmunoprecipitation, anti tag western blot, anti bait coimmunoprecipitation, western blot
      anti tag coimmunoprecipitation, molecular weight estimation by staining, tandem affinity purification, Identification by mass spectrometry, chromatography technology, ion exchange chromatography, western blot, pull down, autoradiography
      pull down, molecular weight estimation by staining, anti tag coimmunoprecipitation, western blot, ion exchange chromatography, peptide massfingerprinting, chromatography technology
      anti bait coimmunoprecipitation, western blot
      anti tag coimmunoprecipitation, Identification by mass spectrometry
      anti tag coimmunoprecipitation, Identification by mass spectrometry
      molecular sieving, anti tag coimmunoprecipitation, western blot, peptide massfingerprinting
      pull down, western blot, molecular sieving, molecular weight estimation by staining, ion exchange chromatography, anti tag coimmunoprecipitation, Identification by mass spectrometry, autoradiography
      pull down, autoradiography
      molecular sieving, molecular weight estimation by staining, anti bait coimmunoprecipitation, western blot, surface plasmon resonance, pull down, molecular weight estimation by silver staining, anti tag western blot, isothermal titration calorimetry, predetermined participant, x-ray crystallography, cosedimentation, fluorescence polarization spectroscopy
      molecular sieving, molecular weight estimation by staining, pull down, autoradiography, x-ray crystallography, predetermined participant, isothermal titration calorimetry, surface plasmon resonance, cosedimentation
      anti bait coimmunoprecipitation, peptide massfingerprinting, ion exchange chromatography, cosedimentation, molecular weight estimation by staining, western blot
      anti tag coimmunoprecipitation, multidimensional protein identification technology
      anti tag coimmunoprecipitation, western blot
      anti tag coimmunoprecipitation, western blot
      molecular sieving, molecular weight estimation by staining, anti tag coimmunoprecipitation, Identification by mass spectrometry
      anti bait coimmunoprecipitation, western blot
      anti bait coimmunoprecipitation, Identification by mass spectrometry, western blot, molecular sieving, molecular weight estimation by staining
      anti tag coimmunoprecipitation, western blot, molecular sieving, molecular weight estimation by staining, Identification by mass spectrometry, anti bait coimmunoprecipitation
      anti bait coimmunoprecipitation, Identification by mass spectrometry, western blot, affinity chromatography technology
      anti bait coimmunoprecipitation, western blot
      anti bait coimmunoprecipitation, western blot
      affinity technology, molecular weight estimation by staining, anti bait coimmunoprecipitation, western blot
      anti tag coimmunoprecipitation, anti tag western blot
      anti tag coimmunoprecipitation, Identification by mass spectrometry, molecular weight estimation by staining, molecular sieving, western blot
      anti bait coimmunoprecipitation, western blot, anti tag coimmunoprecipitation
      anti tag coimmunoprecipitation, anti tag western blot
      anti bait coimmunoprecipitation, western blot
      anti bait coimmunoprecipitation, western blot
      anti bait coimmunoprecipitation, western blot, ion exchange chromatography, cosedimentation, molecular weight estimation by staining
      anti bait coimmunoprecipitation, western blot
      anti bait coimmunoprecipitation, western blot
      anti tag coimmunoprecipitation, Identification by mass spectrometry
      anti bait coimmunoprecipitation, western blot
      anti bait coimmunoprecipitation, western blot, anti tag coimmunoprecipitation, anti tag western blot, coimmunoprecipitation
      anti tag coimmunoprecipitation, western blot, anti bait coimmunoprecipitation, anti tag western blot
      anti bait coimmunoprecipitation, western blot
      anti tag coimmunoprecipitation, Identification by mass spectrometry
      anti tag coimmunoprecipitation, Identification by mass spectrometry
      anti tag coimmunoprecipitation, Identification by mass spectrometry
      anti tag coimmunoprecipitation, Identification by mass spectrometry
      anti tag coimmunoprecipitation, western blot, peptide massfingerprinting
      anti bait coimmunoprecipitation, western blot
      anti bait coimmunoprecipitation, western blot
      anti bait coimmunoprecipitation, western blot
      anti tag coimmunoprecipitation, molecular weight estimation by staining, chromatography technology, pull down, isothermal titration calorimetry, predetermined participant, ion exchange chromatography, western blot, x-ray crystallography
      anti bait coimmunoprecipitation, western blot
      anti tag coimmunoprecipitation, Identification by mass spectrometry
      anti tag coimmunoprecipitation, western blot
      RNA-protein
      Interacting group
      Assay
      References
      Alleles Reported to Model Human Disease (Disease Ontology) (4 alleles)
      Models Based on Experimental Evidence ( 2 )
      Allele
      Disease
      Evidence
      References
      Modifiers Based on Experimental Evidence ( 1 )
      Allele
      Disease
      Interaction
      References
      Models Based on Experimental Evidence ( 1 )
      Allele
      Disease
      Evidence
      References
      Modifiers Based on Experimental Evidence ( 1 )
      Allele
      Disease
      Interaction
      References
      Alleles Representing Disease-Implicated Variants
      Genetic Tools, Stocks and Reagents
      Sources of Stocks
      Contact lab of origin for a reagent not available from a public stock center.
      Bloomington Stock Center Disease Page
      Related mammalian, viral, bacterial, or synthetic transgenes
      Allele
      Transgene
      Publicly Available Stocks
      Selected Drosophila transgenes
      Allele
      Transgene
      Publicly Available Stocks
      RNAi constructs available
      Allele
      Transgene
      Publicly Available Stocks
      Selected Drosophila classical alleles
      Allele
      Allele class
      Mutagen
      Publicly Available Stocks
      amorphic allele - molecular evidence
      Delta2-3 transposase
      References (5)