Current Genetic Status of Nagaremon-charr, a Threatened Morphotype of Salvelinus leucomaenis in the Ane River, Lake Biwa System, Central Japan, With Comments on Its Conservation.

Stream-dwelling white-spotted charr, Salvelinus leucomaenis, populations tend to have unique color and spot patterns in different regions and may even display stream-specific patterns. An extreme edge of such diversity, found in individuals with atypical body color patterns (so-called nagaremon-type charr, a rare morphotype of Salvelinus leucomaenis [hereafter termed nagaremon-charr]), sympatrically occurring with normal-charr, has been reported from only six small isolated populations in Japan. Based on morphological and ecological perspectives, nagaremon-charr has been considered as an intraspecific color variant of white-spotted charr, although the genetic status of nagaremon-charr has not been determined. In this study, genetic diversity and population structure of the nagaremon-charr in a tributary of the Ane River (Lake Biwa system) were investigated through microsatellite and mtDNA analyses. Nagaremon-charr and sympatric normal-charr in the tributary shared the mtDNA haplotypes and were assigned to the same cluster in the STRUCTURE analysis and discriminant analysis of principal components (DAPC). These results suggested that nagaremon-charr in the Ane River is an intra-populational specific color variant of white-spotted charr. Above a waterfall, nagaremon-charr specimens exhibited extremely reduced genetic diversity, indicating that genetic drift may account for the fixation of the nagaremon-morphotype. Normal-charr below the waterfall clustered separately from hatchery-reared charr, indicative of native status of the former. Thus, both nagaremon-charr and normal-charr in the entire Ane River tributary should be conserved.

Grade 1 Endometrioid Carcinoma With an Area of Serous Carcinoma Less than 5% Is More Aggressive than Stage IA Pure-type Grade 1 Endometrioid Carcinoma.

BACKGROUND/AIM: In 2020, the percentages were removed from the World Health Organization's criteria for mixed carcinoma. The aim was to examine the clinical significance of an area of serous carcinoma (SC) <5%. PATIENTS AND METHODS: Our study included 236 patients with the 2009 International Federation of Obstetrics and Gynecology (FIGO) stage IA grade 1 endometrioid carcinoma (EG1) from multiple hospitals. EG1 patients with an area of SC <5% and those with pure-type EG1 were retrospectively compared. RESULTS: In the multivariate analysis for recurrence, an area of SC <5% was an independent risk factor [hazard ratio (HR)=101.51, p<0.01]. In the multivariate analysis for progression-free survival, an area of SC <5% was identified as a negative prognostic factor (HR=62.43, p<0.01). CONCLUSION: EG1 with an area of SC <5% may be more aggressive than pure-type EG1 at FIGO stage IA.