Timing and duration of mating and brooding periods of Atka mackerel (Pleurogrammus monopterygius) in the North Pacific Ocean

The timing and duration of the reproductive cycle of Atka mackerel (Pleurogrammus monopterygius) was validated by using observations from time-lapse video and data from archival tags, and the start, peak, and end of spawning and hatching were determined from an incubation model with aged egg samples and empirical incubation times ranging from 44 days at a water temperature of 9.85°C to 100 days at 3.89°C. From June to July, males ceased diel vertical movements, aggregated in nesting colonies, and established territories. Spawning began in late July, ended in mid-October, and peaked in early September. The male egg-brooding period that followed continued from late November to mid-January and duration was highly dependent on embryonic development as affected by ambient water temperature. Males exhibited brooding behavior for protracted periods at water depths from 23 to 117 m where average daily water temperatures ranged from 4.0° to 6.2°C. Knowledge about the timing of the reproductive cycle provides a framework for conserving Atka mackerel populations and investigating the physical and biological processes influencing recruitment

Effects of Maternal Growth on Fecundity and Egg Quality of Wild and Captive Atka Mackerel

Trade-offs in energy allocation between growth and reproduction can result in variations in reproductive potential in fish with differing growth patterns. Spawning biomass is often used as a proxy for reproductive potential on the assumption that fecundity is directly proportional to body weight. We examined variations in the reproductive potential of Atka mackerel Pleurogrammus monopterygius by studying the effect of differential growth and condition patterns on fecundity, atresia, and egg energy. Fecundity and egg energy were determined for fish from two geographic areas, Seguam Pass and Amchitka Island, Alaska, and compared with those of fish held in captivity. These Atka mackerel showed distinct differences in growth and condition, with weight at length and length at age being the highest among captive fish, intermediate among fish from Seguam Pass, and lowest among fish from Amchitka Island. Realized fecundity showed that on average captive fish spawned seven batches, fish from Seguam Pass six batches, and fish from Amchitka Island five batches. For wild fish, potential and realized fecundity at length or age was significantly higher at Seguam Pass than at Amchitka Island, whereas the fecundity-at-weight relationship did not differ by area, suggesting that weight is a better predictor of fecundity than length or age. Atresia and batch fecundity by length or weight did not differ by area, suggesting that the variation in fecundity is better explained by the variation in batch number than by batch size. Oocyte dry weight was higher for captive fish than for wild fish, whereas batch order did not significantly affect oocyte dry weight. Increased potential fecundity, realized fecundity, and oocyte quality in Atka mackerel females were strongly related to body size, indicating that growth differences and maternal feeding success impact the fecundity and oocyte quality of Atka mackerel. Therefore, changes in growth and condition patterns need to be taken into account to accurately estimate the reproductive potential of this species

Association of a functional variant downstream of TNFAIP3 with systemic lupus erythematosus

Systemic Lupus Erythematosus (SLE, OMIM 152700) is an autoimmune disease characterized by self-reactive antibodies resulting in systemic inflammation and organ failure. TNFAIP3, encoding the ubiquitin-modifying enzyme A20, is an established susceptibility locus for SLE. By fine mapping and genomic resequencing in ethnically diverse populations we fully characterized the TNFAIP3 risk haplotype and isolated a novel TT>A polymorphic dinucleotide associated with SLE in subjects of European (P = 1.58 × 10(−8); odds ratio (OR) = 1.70) and Korean (P = 8.33 × 10(−10); OR = 2.54) ancestry. This variant, located in a region of high conservation and regulatory potential, bound a nuclear protein complex comprised of NF-κB subunits with reduced avidity. Furthermore, compared with the non-risk haplotype, the haplotype carrying this variant resulted in reduced TNFAIP3 mRNA and A20 protein expression. These results establish this TT>A variant as the most likely functional polymorphism responsible for the association between TNFAIP3 and SLE