Photoperiodism is an adaptation mechanism that enables animals to predict seasonal changes in the environment. Japanese quail is the best model organism for studying photoperiodism. Although the recent availability of chicken genome sequences has permitted the expansion from single gene to genome-wide transcriptional analysis in this organism, the photoperiodic response of the domestic chicken is less robust than that of the quail. Therefore, in the present study, we examined the photoperiodic response of the red jungle fowl (Gallus gallus), a predecessor of the domestic chicken, to test whether this animal could be developed as an ideal model for studying the molecular mechanisms of seasonal reproduction. When red jungle fowls were transferred from short-day- to long-day conditions, gonadal development and an increase in plasma LH concentration were observed. Furthermore, rapid induction of thyrotropin beta subunit, a master regulator of photoperiodism, was observed at 16 h after dawn on the first long day. In addition, the long-day condition induced the expression of type 2 deiodinase, the key output gene of photoperiodism. These results were consistent with the results obtained in quail and suggest that the red jungle fowl could be an ideal model animal for the genome-wide transcriptional analysis of photoperiodism.
Background: Human metapneumovirus (hMPV) and respiratory syncytial virus (RSV) are the leading causes of acute respiratory illness in children. Clinical burden of each infection on the respiratory distress in asthmatic patients remains unclear. The purpose of the study was to clarify the effect of these infections on the severity of asthmatic children in the seasonal outbreaks. Methods: A total of 1,217 pediatric inpatients with hMPV (n = 114) or RSV (n = 1,103) infection in Yamaguchi prefecture, Japan, between 2011 and 2014 were enrolled. Bronchial asthma was defined as having more than 3 episodes of wheezing illness over 1 year of age. Infection was determined by the positive antigen test for each virus in the nasal specimens. Results: The number of patients peaked at age 12–15 months in hMPV infection and at age 0–3 months in RSV infection. The proportion of hypoxic patients (40–50%) did not differ at any age between hMPV-infected and RSV-infected children. In the analysis of date from > 1 year old patients with hypoxia, hMPV-infection group was older ( P = 0.036), and more frequently had history of asthma ( P = 0.015) or abnormal chest roentgenogram ( P < 0.001) than RSV-infection group. Multivariate analysis indicated that the hypoxia-associated factors were history of asthma in both hMPV (odds ratio [OR]: 15.8; P < 0.001) and RSV infections (OR, 2.2; P = 0.005), higher body temperature in hMPV infection (OR, 2.2; P = 0.009), and younger age in RSV infection (OR, 1.4; P = 0.004). Conclusions: Outbreaks of hMPV, rather than, RSV infection may have a greater impact on the development of hypoxic respiratory illness in asthmatic children.
To investigate additional endpoints for screening of endocrine disruptors in birds, effects of 17beta-estradiol (E2) on one-generation reproduction in the Japanese quail (Coturnix japonica) were assessed. Pairs of the 10-week-old Japanese quail were fed a low-phytoestrogen diet containing E2 at 0 (control), 10, 100, and 1,000 ppm for six weeks. In the E2 100- and 1,000-ppm groups, the parental quail represented marked toxic changes including high mortality, decreased food consumption, decreased gonad weights, gross and histologic toxic changes in the reproductive and other organs, and inhibition of the reproduction. However, no adverse effects were observed in the parental quail from the E2 10-ppm group. In the parental males, serum vitellogenin (VTG) concentrations were increased significantly in the E2 10-ppm group, disclosing that serum VTG concentration is one of the highly sensitive endpoints for evaluating estrogenic endocrine activities. In the E2 10-ppm group, number of eggs laid, number of eggs with abnormalities, eggshell strength and thickness, fertility, early and late viabilities of embryos, normal hatchling rate, and clinical signs, mortality, viability, and body weight of chicks at 14 d of age were not affected. However, histopathology of the chicks in the E2 10-ppm group revealed meaningful morphological changes in the reproductive organs, such as cystic dilatation of seminiferous tubules, increased interstitial cells in the testis, and decreased theca cells in the ovary. The present study suggests that serum VTG concentration in the parental quail and histopathology of reproductive organs in the offspring are sensitive endpoints and are useful as additional endpoints in the avian one-generation reproduction test using the Japanese quail for evaluating estrogenic endocrine-disrupting effects.
Abstract Background Panda ( s ) is an autosomal recessive mutation, which displays overall white plumage color with spots of wild-type plumage in the Japanese quail ( Coturnix japonica ). In a previous study, the s locus was included in the same linkage group as serum albumin ( Alb ) and vitamin-D binding protein ( GC ) which are mapped on chicken ( Gallus gallus ) chromosome 4 (GGA4). In this study, we mapped the s locus on the microsatellite linkage map of the Japanese quail by linkage analysis. Results Segregation data on the s locus were obtained from three-generation families ( n = 106). Two microsatellite markers derived from the Japanese quail chromosome 4 (CJA04) and three microsatellite markers derived from GGA4 were genotyped in the three-generation families. We mapped the s locus between GUJ0026 and ABR0544 on CJA04. By comparative mapping with chicken, this locus was mapped between 10.0 Mb and 14.5 Mb region on GGA4. In this region, the endothelin receptor B subtype 2 gene ( EDNRB2 ), an avian-specific paralog of the mammalian endothelin receptor B gene ( EDNRB ), is located. Because EDNRB is responsible for aganglionic megacolon and spot coat color in mouse, rat and equine, EDNRB2 is suggested to be a candidate gene for the s locus. Conclusion The s locus and the five microsatellite markers were mapped on CJA04 of the Japanese quail. EDNRB2 was suggested to be a candidate gene for the s locus.
