Genetic variability associates with ancestry, age at disease onset, organ involvement and disease severity in juvenile-onset systemic lupus erythematosus

\ua9 2025 The Author(s). Juvenile-onset systemic lupus erythematosus (jSLE) is a complex autoimmune/inflammatory disease in which genetic factors likely contribute to pathophysiology and clinical expression. This study explored associations between general (alternate allele counts; AAC) and gene-specific (alternate allele scores; GAAS) sequence variability, age at onset, sex, ancestry, disease activity/severity, organ involvement and treatments in jSLE. 289 participants from the UK JSLE Cohort Study underwent panel sequencing of 62 genes/genomic regions. Weighted AAC and GAAS were calculated. Correlation analyses and generalized linear models assessed associations between genetic burden, ancestry, age at diagnosis and clinical variables. AAC inversely correlated with age at diagnosis (R = -0.15, p = 0.01), primarily driven by South Asians (R = -0.28, p < 0.001). African/Caribbean patients exhibited higher AAC (p < 0.001). Clinical variables, including severity of renal involvement (ACP5, ITGAM, LYN, p < 0.001; TNFAIP3, p = 0.007), associated with GAAS. Genetic variability likely contributes to early disease expression and severity in jSLE, supporting patient stratification and personalised care

Scaling matters: incorporating body composition into Weddell seal seasonal oxygen store comparisons reveals maintenance of aerobic capacities

Adult Weddell seals (Leptonychotes weddellii) haul-out on the ice in October/November (austral spring) for the breeding season and reduce foraging activities for ~4 months until their molt in the austral fall (January/February). After these periods, animals are at their leanest and resume actively foraging for the austral winter. In mammals, decreased exercise and hypoxia exposure typically lead to decreased production of O2-carrying proteins and muscle wasting, while endurance training increases aerobic potential. To test whether similar effects were present in marine mammals, this study compared the physiology of 53 post-molt female Weddell seals in the austral fall to 47 pre-breeding females during the spring in McMurdo Sound, Antarctica. Once body mass and condition (lipid) were controlled for, there were no seasonal changes in total body oxygen (TBO2) stores. Within each season, hematocrit and hemoglobin values were negatively correlated with animal size, and larger animals had lower mass-specific TBO2 stores. But because larger seals had lower mass-specific metabolic rates, their calculated aerobic dive limit was similar to smaller seals. Indicators of muscular efficiency, myosin heavy chain composition, myoglobin concentrations, and aerobic enzyme activities (citrate synthase and β-hydroxyacyl CoA dehydrogenase) were likewise maintained across the year. The preservation of aerobic capacity is likely critical to foraging capabilities, so that following the molt Weddell seals can rapidly regain body mass at the start of winter foraging. In contrast, muscle lactate dehydrogenase activity, a marker of anaerobic metabolism, exhibited seasonal plasticity in this diving top predator and was lowest after the summer period of reduced activity

Measurement of the linear dynamics of the descent of the bovine fetal testis

Measurements were made on 86 male bovine fetuses collected from abattoirs in the vicinity of Sydney, Australia. The fetal body length was used to calculate the approximate day of gestational age (DGA); most fetuses were between 60 and 150 DGA. The distances from the caudal pole of the kidney (metanephros) to, respectively, the tip of the scrotum, the distal end of the testis and the internal ring of the inguinal canal were measured, as well as the dimensions of the testis and gubernaculum testis. Distances of (1) testis to inguinal canal, (2) inguinal canal to scrotum, (3) testis to scrotum and (4) gubernaculum to scrotum were calculated from these measurements, which were made on both left and right sides. The total length of the gubernaculum testis increased during transabdominal passage and during transinguinal passage of the testis. Furthermore, the gubernaculum appeared to maintain the testis at a relatively fixed distance from the scrotum during transabdominal passage so that the inguinal canal appeared to move towards the testis. The greatest distance between the testis and the tip of the scrotum was found during the transinguinal passage of the testis and was 2.8 cm for the left testis and 2.3 cm for the right. When located within the scrotum, each testis was still 1.6–1.7 cm from the tip of the scrotum, so the distance to be traversed was only 0.6–1.2 cm. Following passage of the testis through the inguinal canal, the gubernaculum became shorter and its distal tip was displaced toward the distal end of the scrotum. Traction by the gubernaculum could account for the final transposition of the testis from the external inguinal ring to the scrotum. Other factors involved in displacement of the testis include differential growth patterns as well as increases in the dimensions of the testis itself

Studies on triploid oysters in Australia .6. Gonad development in diploid and triploid Sydney rock oysters Saccostrea commercialis (Iredale and Roughley)

Triploid Sydney rock oysters, Saccostrea commercialis (produced using cytochalasin B to treat newly fertilised eggs), were sampled from 22-34 months of age to encompass a full reproductive season. A comparative assessment of the extent of gametogenesis was made for both diploid and triploid Sydney rock oysters. It was necessary to develop separate staging criteria for the triploids. Triploid gametogenesis was highly retarded compared to the diploids. The extent of retardation of gametogenesis in the triploids was more severe than that observed for triploid Pacific oysters. In particular, triploid females developed abnormally and follicle branching was severely retarded with few mature ova present. Development in the male triploid appeared to hall at spermatocyte formation; on the few occasions that spermatids were present they were sparsely distributed throughout the gonad. In the thirteen months of sampling, there was no evidence of spawning in the triploids. Very few hermaphrodites were found in either diploids or triploids sampled. Sex ratios showed little change over time for diploids and for triploid males but the incidence of triploid females increased between January and May. The gonad area indices for triploids (sexes combined) were consistently much lower than for those of either diploid males or females