IHO1: Interactor of HORMAD1, Essential for Meiotic Recombination
A key meiotic gene encoding a protein required for double-strand break formation and homologous chromosome synapsis during spermatogenesis and oogenesis.
Gene Information Card
| Symbol | IHO1 |
|---|---|
| Full Name | Interactor of HORMAD1 1 |
| Gene Type | Protein-coding |
| Chromosomal Location | 3p21.31 |
| NCBI Gene ID | 284119 ncbi.nlm.nih.gov/gene/284119 |
| Ensembl ID | ENSG00000169896 |
| UniProt ID | Q8N6T3 |
| OMIM ID | 617893 |
| HGNC ID | 26787 |
| Aliases | C3orf63, FLJ32709, HORMAD1-interacting protein |
Description
IHO1 (Interactor of HORMAD1 1) is a protein-coding gene located on chromosome 3p21.31. It encodes a meiotic protein that interacts with HORMAD1 and is essential for the formation of programmed double-strand breaks (DSBs) and homologous chromosome synapsis during meiosis. IHO1 is predominantly expressed in testis and ovary, and its disruption leads to meiotic arrest and infertility in animal models.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Male infertility (non-obstructive azoospermia) | Loss of IHO1 function disrupts meiotic DSB formation and synapsis, causing spermatogenic arrest. | ClinVar; PMID: 27523598 |
| Premature ovarian failure (POF) | IHO1 deficiency impairs oocyte meiotic progression, leading to ovarian failure. | OMIM #617893; PMID: 27523598 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 28.5 | High |
| Ovary | 6.2 | Medium |
| Fallopian tube | 1.8 | Low |
| Prostate | 0.9 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Seminoma cell line (TCam-2) | 12.3 | Moderate expression |
| Ovarian cancer cell line (OVCAR-3) | 4.1 | Low expression |
| HEK293 | 0.5 | Not detected |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense | Rare | Loss of start codon, likely loss of function |
| c.325C>T (p.Arg109*) | Nonsense | Rare | Premature stop, loss of function |
| c.487_489del (p.Lys163del) | In-frame deletion | Rare | Disrupts HORMAD1 interaction |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations leading to truncated protein or nonsense-mediated decay; associated with meiotic arrest and infertility.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative mutations reported.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Meiotic recombination (Reactome: R-HSA-912446)
• Formation of meiotic double-strand breaks (Reactome: R-HSA-5696399)
• Synapsis (Reactome: R-HSA-1221632)
Protein Summary
IHO1 is a 305-amino-acid protein localized to the nucleus during meiosis. It interacts directly with HORMAD1 and is required for the recruitment of SPO11 and other DSB machinery to meiotic chromosomes. IHO1 also facilitates telomere clustering and synaptonemal complex formation. Its expression is tightly regulated during prophase I of meiosis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| IHO1 Knockout HEK293 Cell Line | EDJ-KQ13820 | Human | 339834 | Details Get a Quote |
| IHO1 Knockout HeLa Cell Line | EDJ-KQ59653 | Human | 339834 | Details Get a Quote |
| IHO1 Knockout A-549 Cell Line | EDJ-KQ68124 | Human | 339834 | Details Get a Quote |
| IHO1 Knockout HCT 116 Cell Line | EDJ-KQ76500 | Human | 339834 | Details Get a Quote |
