{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nRecent investigations into testis‐expressed genes have identified THEG as a novel, testis‐specific nuclear protein that is predominantly expressed in spermatids. In a transgenic mouse model (kisimo mouse), disruption of the THEG locus was associated with abnormal elongation of spermatids, and molecular analyses revealed that THEG interacts strongly with the chaperonin-containing t-complex polypeptide-1ε, suggesting a role for THEG in modulating protein assembly during the later stages of spermatogenesis."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": "Subsequent targeted gene disruption studies further explored THEG’s function by deleting distinct protein domains. In one model, the C-terminal region (amino acids 137–376) was removed without major impact on spermatogenesis or fertility, whereas in another model complete loss of THEG transcripts—achieved by deleting the N-terminal domain—also failed to produce overt defects in testicular morphology or sperm function. These results indicate that, despite its specific expression in haploid germ cells, THEG is not essential for normal spermatogenesis in mice."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "2"}]}, {"type": "t", "text": "Collectively, the data portray THEG as a testis-specific factor potentially involved in the assembly of spermatid protein complexes, yet its absence does not critically impair sperm development under standard conditions. This dichotomy underscores the possibility that THEG might have a modulatory or context-dependent role, warranting further investigation into its function under varied physiological or stress-related scenarios."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": ""}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "N Yanaka, K Kobayashi, K Wakimoto, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Insertional mutation of the murine kisimo locus caused a defect in spermatogenesis."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "J Biol Chem (2000)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1074/jbc.C901047199"}], "href": "https://doi.org/10.1074/jbc.C901047199"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "10747865"}], "href": "https://pubmed.ncbi.nlm.nih.gov/10747865"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "Ashraf U Mannan, Karim Nayernia, Christian Mueller, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Male mice lacking the Theg (testicular haploid expressed gene) protein undergo normal spermatogenesis and are fertile."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Biol Reprod (2003)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1095/biolreprod.103.017400"}], "href": "https://doi.org/10.1095/biolreprod.103.017400"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "12748127"}], "href": "https://pubmed.ncbi.nlm.nih.gov/12748127"}]}]}]}