| Claim/annotation | Evidence type (genetics/expression/quantitative/resource) | Key details (numbers, tissues, alleles, interactions) | Source (author year, venue, DOI/URL) |
|---|---|---|---|
| **Identity mapping**: **lon-8 = Y59A8B.20** in *C. elegans*; encodes a **small secreted precursor** | genetics/expression | ORF **Y59A8B.20** named **lon-8**; predicted **162 aa** protein with **N-terminal signal peptide**; no TM/lipid anchor noted; one deletion allele (**hu187**) yields alternative transcript predicted to **lack the signal peptide** (pqac-00000000, pqac-00000007, pqac-00000010) | Soete et al. 2007, *BMC Developmental Biology*; DOI: https://doi.org/10.1186/1471-213X-7-20 |
| **Primary function**: regulator of **body size/larval elongation** | genetics/quantitative | RNAi against Y59A8B.20 increased body length from **1.3 ± 0.08 mm** to **1.4 ± 0.08 mm** (**n = 75**); deletion alleles **lon-8(hu187)** and **lon-8(hu188)** produce clear **Lon** phenotype; mutants are reported as about **~10% longer** than wild type (pqac-00000000, pqac-00000007, pqac-00000008) | Soete et al. 2007, *BMC Developmental Biology*; DOI: https://doi.org/10.1186/1471-213X-7-20 |
| **Cellular localization / site of action**: hypodermis-derived, likely extracellular/cuticular | expression | Strong reporter expression in **hypodermal syncytium**, especially **hyp4** and **hyp7**; clear cellular localization required deletion of signal peptide from reporter because native N-terminus could cause **secretion/diffusion of GFP**; supports extracellular secretion from epidermis (pqac-00000000, pqac-00000006, pqac-00000013) | Soete et al. 2007, *BMC Developmental Biology*; DOI: https://doi.org/10.1186/1471-213X-7-20 |
| **Male tail / ray morphogenesis role** | genetics/expression | **lon-8(hu187)** and **lon-8(hu188)** males show **Ram-like** defects; **all rays abnormal**, with **rays 5 and 6 most severe**; rays can appear **clumped as an amorphous mass**; males remain able to mate; reporter expressed in ventral male tail hypodermis around developing rays, including **V6.pppaa, T.aa, R6.p, T.apapa, R7.p, R8.p, R9.p** (pqac-00000004, pqac-00000008, pqac-00000011, pqac-00000013) | Soete et al. 2007, *BMC Developmental Biology*; DOI: https://doi.org/10.1186/1471-213X-7-20 |
| **Pathway placement**: acts outside direct transcriptional control of **DBL-1/Sma/Mab (TGF-β)** | genetics/expression | **lon-8** expression not detectably changed in **dbl-1** or **sma-6** mutants; **dbl-1** suppresses the lon-8 body-size phenotype, but data support action **in parallel/independent** rather than as a direct DBL-1 transcriptional target (pqac-00000005, pqac-00000006, pqac-00000011) | Soete et al. 2007, *BMC Developmental Biology*; DOI: https://doi.org/10.1186/1471-213X-7-20 |
| **Cuticle/aECM association** via collagen-modifying enzymes | genetics | **dpy-11(RNAi)** and **dpy-18(RNAi)** completely suppress the lon-8 body-size phenotype; these genes encode **cuticle collagen modifying enzymes**, implicating LON-8 in **cuticle composition/assembly** or regulation of cuticle-associated targets (pqac-00000000, pqac-00000003, pqac-00000004, pqac-00000009) | Soete et al. 2007, *BMC Developmental Biology*; DOI: https://doi.org/10.1186/1471-213X-7-20 |
| **Mechanistic constraint**: Lon phenotype is **not explained by increased hypodermal cell number or ploidy** | quantitative | Hypodermal nuclei counts unchanged (**21 ± 1**, **n = 20**); seam cell nuclei unchanged (**16–17**, **n = 32**); hypodermal ploidy not detectably changed (**7.9 ± 1.6** in N2 vs **8.2 ± 2.4** in **lon-8(hu188)**, **n ≈ 10**); supports a model involving **cell size / matrix properties** rather than extra cells (pqac-00000001, pqac-00000010) | Soete et al. 2007, *BMC Developmental Biology*; DOI: https://doi.org/10.1186/1471-213X-7-20 |
| **Evolutionary context**: conserved in rhabditid nematodes | expression/quantitative | Homologs reported across **Rhabditida**; N-termini are divergent but consistently predicted to be **signal peptides**, reinforcing conserved secretion/extracellular localization (pqac-00000003, pqac-00000005, pqac-00000009) | Soete et al. 2007, *BMC Developmental Biology*; DOI: https://doi.org/10.1186/1471-213X-7-20 |
| **Review-level annotation**: secreted aECM/cuticle factor important for male rays | resource | Review on *C. elegans* apical extracellular matrices lists **LON-8** among proteins important for building **male rays**, describing it as a **short, secreted peptide/protein** in the ray/cuticle context (pqac-00000016) | Cohen & Sundaram 2020, *Journal of Developmental Biology*; DOI: https://doi.org/10.3390/jdb8040023 |
| **Recent resource / real-world implementation**: endogenous fluorescent tagging | resource | Systematic aECM study generated an endogenous **lon-8::mNG** knock-in, explicitly describing **LON-8** as a **novel secreted protein** implicated in **body cuticle morphology**; useful for in vivo localization and functional follow-up (pqac-00000012) | Ragle et al. 2025, *bioRxiv*; DOI: https://doi.org/10.1101/2025.05.14.653803 |


*Table: This table summarizes the strongest functional annotation evidence for *C. elegans* lon-8/Y59A8B.20, including secretion, hypodermal expression, body-size and male-tail phenotypes, pathway relationships, and recent tagging resources. It is useful as a compact evidence map linking specific claims to quantitative results and source citations.*