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FB2026_01
,
released March 12, 2026
Identified in a GWAS analysis of Chinese men with non-obstructive azoospermia (FBrf0227519), the human genes ESRRB and ESRRG are proposed as candidate genes for involvement in human male fertility. ESRRB and ESRRG encode similar nuclear estrogen-related receptors. Work done in Drosophila has used the fly gene orthologous to both ESRRB and ESRRG, Dmel\ERR, thus results for both are compiled in this report. For Dmel\ERR, classical mutations, alleles created by targeted recombination, RNAi-targeting constructs, and alleles caused by insertional mutagenesis have been generated. ESRRB has also been implicated in a form of deafness in humans (MIM:602167). Dmel\ERR is orthologous to one additional human gene, ESRRA.
Neither ESRRB nor ESRRG has been introduced into flies.
Animals homozygous for amorphic alleles of Dmel\ERR are typically lethal during larval development. Tissue-specific knockdown of ERR using GAL4/UAS-RNAi results in reduced male fertility; functional ERR is required in the somatic cells of the testis for normal fertility. Physical interactions of the Dmel\ERR protein product have been described; see below and in the FlyBase gene report for ERR.
[updated Apr. 2016 by FlyBase; FBrf0222196]
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).
Observation of non-obstructive azoospermia (NOA).
Homologous loci identified in a genome-wide association study (GWAS) of non-obstructive azoospermia in Chinese men.
ESRRB and ESRRG encode nuclear estrogen-related receptors. All members of the ESRR family share an almost identical DNA binding domain, which is composed of two C4-type zinc finger motifs. Members of the ESRR family appear to target the same genes as the estrogen receptor (ER) family, modulating the ER-mediated estrogen response in various ways. [from Gene Cards, ESRRG; 2016.0407]
Many to one: 3 human to 1 Drosophila; additional high-scoring human orthologous genes are ESRRB and ESRRA.
Many to one: 3 human to 1 Drosophila; additional high-scoring human orthologous genes are ESRRG and ESRRA.
Ortholog of human genes ESRRB, ESRRG and ESRRA. (1 Drosophila to 3 human). Dmel\ERR shares 38-42% identity and 51-53% similarity with the human genes.