Function In Japanese Quail Research Articles

Exposure of Avian Embryos to Cycling Incubation Temperatures Reduces Adult Bactericidal Ability.

In birds, the temperature at which eggs are incubated shapes many aspects of hatchling phenotype, but long-term effects are less studied. We studied the effect of incubation temperature and pattern on the subsequent development of innate immune function in Japanese quail (Coturnix japonica). We incubated quail eggs in one of three replicated treatments: control (37.5°C), low (36.0°C), and cyclical incubation. The cyclical treatment had the same average temperature as the low-temperature treatment (36.0°C) and an upper temperature that was the same as the control. When individuals were 5, 20, and 55 d of age (i.e., adults), we measured the ability of blood plasma to kill Escherichia coli. Throughout development there was a nonsignificant trend for immune function to be lower in the cycling treatment. In adulthood, however, individuals incubated at cycling temperatures had significantly lower immune function than control birds but did not differ from individuals incubated at constant low temperatures. Males and females responded similarly to the incubation treatment, but females developed a greater plasma bactericidal ability than males. We conclude that variation in innate immune function of adult birds is shaped by temperature fluctuations experienced during incubation.

Comparison of growth curves using non-linear regression function in Japanese quail

ABSTRACTThis study was conducted to determine the goodness of fit of Gompertz, Logistic, Von Bertalanffy, Richards, Levakovich and Janoschek growth models in Japanese quail. Therefore, weekly live-weight data obtained from 372 females and 339 males were fitted. Females’ live weights were found to be higher than that of males, and the first divergence in the growth of female and male birds occurred in 21–28 days, and it survived until the experiment (P < .001). The coefficient of determination (R2), adjusted coefficient of determination (adj. R2), mean square error (MSE), Akaike’s information criteria (AIC) and Bayesian information criterion (BIC) were used to determine the best growth model. R2 and adjusted R2 values of the growth models were similar and close to 1, indicating that all models perform well in describing age-related changes in live weight in quail. Based on the MSE, AIC and BIC values, Richards model was determined to be the best fitting model to the growth data of both sexes. Consequently, it has been demonstrated that Richards function which has a flexible structure in terms of inflection point is the most appropriate growth function for both female and male birds.

Histopathology of the Testis as a Sensitive Tool to Detect Potentially Adverse effects of Environmental Chemicals on Male Fertility in Japanese Quail

Histopathology proved a sensitive tool to detect adverse effects of environmental chemicals on testis morphology and function in Japanese quail even if there was no evidence of reduced fertility. This became apparent in one-generation studies with the fungicides vinclozolin and epoxiconazole in which microscopic findings, such as atrophy or epithelial degeneration, paralleled a reduction in spermatid count whereas testis weight was not altered and reproductive success not compromised at the same dose levels. In a study with methyl testosterone in which fertility was in fact reduced, lower spermatid count was accompanied by a strong decrease in testis weight. Histological examination of the testis and counting of spermatids might be suitable and sensitive methods to elucidate the mechanism if a male-mediated decline in reproductive success is suspected.

Reproductive responses and nitric oxide activity in Japanese quail, Coturnix coturnix japonica, are altered by specific phase relationships of neural (serotonergic and dopaminergic) oscillations and pineal function

The present study investigates the effects of temporal synergism of 5-hydroxytryptophan (5-HTP) and l-dihydroxyphenylalanine ( l-DOPA) and pineal function (pinealectomy and melatonin administration) on gonadal response and nitric oxide (NO) activity in Japanese quail. Three-week-old male quails were divided into 9 groups, as follows: (I) control (treated with normal saline); (II) 8-h and (III) 12-h (receiving l-DOPA after the administration of 5-HTP [5 mg/100 g body weight] at the interval of 8 and 12 h, respectively, over a period of 13 days); (IV) SO (sham operated); (V) Px (pinealectomized); (VI) Veh (vehicle treated control); (VII) Mel (melatonin 25 μg/100 g body weight for 45 days); (VIII) 12-h + Veh; and (IX) 12-h + Mel (same as in (III) but further treated with the vehicle or melatonin, respectively, for 32 days). Body weight and cloacal gland volume were recorded weekly, whereas spermatogenesis, plasma testosterone concentration, and total nitrite and nitrate concentration in plasma, hypothalamus, and testes were measured at the termination of the study. Results indicate that compared to the controls, 8-h, Mel, and 12-h + Mel treatments suppressed whereas 12-h and Px stimulated the reproductive system. Further, a significant increase in plasma testosterone, total nitrite, and nitrate in the 12-h and Px groups and a decrease in these concentrations in 8-h, Mel and 12-h + Mel quail were observed. It is evident that 5-HTP and l-DOPA given at the interval of 8 h, as well as melatonin, are potent inhibitors of gonadal development, and the gonado stimulatory effect of the 12-h temporal relationship of the neurotransmitter precursors is masked by the inhibitory effect of melatonin. It is concluded that modulation of the daily phase relationship of neural oscillations and pineal function alters gonadal function and NO activity. Further, NO exhibits a parallel relationship with gonadal function in Japanese quail; this relationship appears to be mediated through NO activity, suggesting a causal relationship, although the mechanism between the 2 systems remains a topic of discussion.

Consequences of in ovo exposure to p, p′-DDE on reproductive development and function in Japanese quail

This study was conduced to assess the effects of a one time embryonic exposure to p, p′-DDE (dichlorodiphenyldichloroethylene; DDE) on the reproductive development and function in Japanese quail ( Coturnix japonica). Embryos were exposed at day one of incubation to either 20 or 40 μg DDE or a sesame oil vehicle control (injection volume = 20 μl). Onset of puberty, gonadal histopathology, sperm motility, cloacal gland size, and male copulatory behavior were assessed in adults. DDE accelerated onset of puberty in females and reduced male reproductive behaviors. Gonadal morphology and sperm motility appeared to be unaffected. Results from this study provide evidence that the neuroendocrine system may be more sensitive and less resilient to embryonic exposure to contaminants than traditional measures of reproductive success following contaminant exposure in adults. This study further supports the inclusion of behavioral assessments in toxicity tests.

Changes in vasotocin immunoreactivity of paraventricular nuclei and adrenal function of Japanese quail in relation to different phases of sexual development

In relevance to osmoregulatory and reproductive functions, activity of hypothalamic neurosecretory neurons may also vary seasonally. The current study was performed to determine annual changes in ir-AVT neurons of hypothalamus and adrenal gland function. We examined changes in ir-AVT neuron by immunohistochemical method and plasma testosterone was measured by enzyme immunoassay. The steroidogenic interrenal activity was studied by histological and biochemical methods. Birds were sampled in February (quiescent), April (recrudescent), June (breeding) and November (regressive). A significant and gradual increase in the number of ir-AVT neurons was observed from quiescent to breeding phase which decreased during regressive phase of annual gonadal cycle. The gradual increase in ir-AVT neurons along with annual gonadal activity of quail were accompanied by increase in plasma levels of testosterone. These results indicate a functional interaction between sex steroid and AVT synthesizing neurons. Adrenal activity (as judged by weight, ascorbic acid content, cortical cord width and cortico-medullary ratio) was also maximum during breeding phase. It is thus postulated that domesticated quail when exposed to natural day length (NDL), exhibits seasonal/annual cyclicity in vastocinergic activity and adrenal function which may be due to difference in sex steroid hormone.

Characterization of CRF, AVT, and ACTH cDNA and pituitary-adrenal axis function in Japanese quail divergently selected for tonic immobility

Higher corticosterone (CORT) responses to acute stress have previously been reported in quail selected for short (STI) duration of tonic immobility (TI) than for long TI (LTI), although behavioral studies indicated that LTI quail were more fearful. To investigate adrenal and pituitary function in these quail lines and their possible involvement in the differences in hypothalamic-pituitary-adrenal (HPA) axis reactivity, we measured CORT responses to adrenocorticotropin (1-24 ACTH), corticotropin-releasing factor (CRF), and arginine vasotocin (AVT) after characterizing the nucleotide acid sequences of these peptides in quail. Although maximum adrenal responses, assessed by ACTH challenge, were higher in STI quail, adrenal sensitivity was comparable for the two genotypes. It is therefore unlikely that differences in HPA axis reactivity involved the adrenal level. AVT and ACTH induced comparable CORT responses in both genotypes, whereas those induced by CRF were much lower. AVT is thus more potent than CRF in quail, but the respective maximum pituitary capacity of both genotypes to secrete ACTH was similar, and it is doubtful that the AVT pathway is involved in the difference in HPA axis reactivity between genotypes. On the other hand, the higher CORT responses induced by CRF in STI quail suggest that CRF might be involved in the differences in HPA axis reactivity between LTI and STI genotypes.

Correlation of nitric oxide (NO) activity and gonadal function in Japanese quail, Coturnix coturnix japonica following temporal phase relation of serotonergic and dopaminergic oscillations

Nitric oxide (NO), a highly reactive and short-lived radical, is considered to be an important trigger molecule for several physiological mechanisms including gonadotrophin releasing hormone (GnRH) secretion in mammals, although there is no such information in avian literature. On the other hand, specific temporal phase relation of circadian neural (serotonergic and dopaminergic) oscillations is reported to modulate reproductive activity in many avian species including Japanese quail. The present study was undertaken to investigate the correlation of NO activity and gonadal function of Japanese quail. In experiment I, the effect of serotonin and dopamine precursors, (5-hydroxytryptophan (5-HTP) and l-dihydroxyphenyalanine ( l-DOPA) respectively; 5 mg per 100 g body weight) administered at intervals of 8 or 12 h over a period of 13 days, was studied on reproductive responses and NO activity. Measurements of body weight, cloacal gland size, testosterone concentration, spermatogenesis, nitrite–nitrate concentration in plasma, hypothalamus and testes, and NADPH-diaphorase (NADPH-d) activity in testes were made on the 2nd, 3rd, 6th and 11th days of treatment and 2nd and 30th day post-treatment. In experiment II, quail were divided into five groups including the control. One experimental group received 13 daily injections of 5-HTP and l-DOPA at intervals of 8 h along with 0.1 ml of normal saline administered orally (8-hr + Veh), while another group of 8-hr quail received NO donor (sodium nitroprusside (SNP), 5 mg per 100 g body weight) orally (8-hr + SNP). The third experimental group received 5-HTP and l-DOPA at intervals of 12 h along with normal saline (12-hr + Veh), while the fourth group of quail along with 5-HTP and l-DOPA at intervals of 12 h also received the NOS inhibitor ( N-nitro- l-arginine methyl ester, l-NAME, 25 μg per 100 g body weight) intraperitoneally (12-hr + l-NAME) for 13 days. This experiment was terminated after 21 days of the treatment. Results indicate that 5-HTP and l-DOPA administered 8 h apart (8-hr) suppressed but if given 12 h apart (12-hr) stimulated the reproductive system and NO activity compared to the control. These effects were apparent on the 6th day of injections and were maintained 30 days following the termination of the treatment. A significant decrease in nitrite and nitrate concentration and NADPH-d activity in reproductively inhibited 8-hr group and an increase in reproductively stimulated 12-hr quail was also evident. In contrast, these activities were stimulated in 8-hr + SNP quail and were suppressed in 12-hr + l-NAME group quail. It is concluded that activity of the reproductive system and NO activity waxes and wanes simultaneously in Japanese quail. Moreover, experimental modulation of gonadal activity (following changes in the phase relation of serotonergic and dopaminergic activity) or NO activity (following the administration of NO modulator or inhibitor) affects each other maintaining a parallel relation between the two systems. Further, it is interesting to note that the gonado-stimulatory effect of SNP overpowers the gonado-inhibitory effects of the 8-hr time interval and inhibitory effects of l-NAME mask the stimulatory effects of 12-hr temporal relation of 5-HTP and l-DOPA administration. These findings strongly suggest that reproductive effects may be induced via changes in NO activity, however the exact mechanism by which NO drives gonadal axis needs to be ascertained.

Immunosenescence and age-related susceptibility to influenza virus in Japanese quail

We evaluated juvenile, pubescent, reproductive adult, and aged Japanese quail ( Coturnix coturnix japonica) to determine if there were age-related differences in immune function with the hypothesis that aged birds would have weaker immune responses. Immune responses were measured using phytohemagglutinin (PHA) skin test, antibody response to foreign red blood cells and exposure to an H9N2 influenza virus. Adult birds consistently had stronger immune responses than young and aged birds. Aged quail had skin responses 38% lower than adults. Pubescent birds’ mean anti-red blood cell response was four-fold lower than adult birds. Adults had greater increase in total anti-viral antibody between primary and secondary infections than all other groups. Our data demonstrate an age-related difference in immune function in Japanese quail that has similarities to age-related immunity in humans; younger and older animals had weaker immune responses compared to young adults.

Reproductive toxicity of trenbolone acetate in embryonically exposed Japanese quail

This study was conducted to assess the effects of a one time embryonic exposure to trenbolone acetate on reproductive development and function in Japanese quail ( Coturnix japonica). Embryos were exposed to either 0.05, 0.5, 5, or 50 μg trenbolone or a sesame oil vehicle control at embryonic day 4. Onset of puberty, gonadal histopathology, sperm motility, cloacal gland size, and male copulatory behavior were assessed in adults. Trenbolone delayed onset of puberty in males, inhibited cloacal gland development, and reduced male reproductive behaviors. Industry laboratories have shown trenbolone acetate to be non-teratogenic in mammalian studies. Our study, however, shows that this one time in ovo exposure delayed onset of puberty in and suppressed adult copulatory behavior in quail males. These results suggest that this one time embryonic exposure to trenbolone may have disrupted development of either the central nervous system or the hypothalamic–pituitary–gonadal axis. This is the first study to demonstrate a demasculinizing effect on copulatory behavior in Japanese quail from embryonic exposure to a non-aromatizable androgenic chemical. More studies are needed to determine the mechanisms behind the observed effects.

Developmental changes in the mRNA levels of IGF-I and its related genes in the reproductive organs of Japanese quail (Coturnix coturnix japonica).

Summary Insulin-like growth factor-I (IGF-I) is involved in the regulation of growth and differentiation of a variety of vertebrate tissues. The biological actions of IGF-I are mediated mainly by the IGF-I receptor (IGF-IR) and partly by the insulin receptor (IR) and modulated by IGF binding proteins (IGFBP). We conducted studies designed to clarify the possible roles of IGF system in the development of the avian reproductive organs. We cloned cDNAs of IGF-I, IGF-IR, IR and IGFBP-2 of Japanese quail and simultaneously measured the expression of these genes in the quail liver, testis and oviduct at different ages using a lysate RNase protection assay. Hepatic IGF-I mRNA levels increased rapidly and remained elevated during the rapid-growing period, which coincided with the period of rapid increase in testicular weight. IGF-I mRNA was detected at each stage of developing testis examined. Its level was high at the early stage and decreased with age. IGFBP-2 mRNA in testis exhibited a similar expression pattern to that of IGF-I, whereas a divergence in IGF-I and IGF-IR gene expression was observed. Both IGF-IR and IR mRNAs increased when the testis grew rapidly and decreased when sexual maturation was almost completed. These results suggest that IGF-I may serve as an autocrine/paracrine regulator as well as an endocrine regulator in the testicular development and function of Japanese quail. In the oviduct, IGF-I, IGF-IR, IR and IGFBP-2 mRNAs were also developmentally regulated. A rapid growth of the oviduct was accompanied by a significant increase in the level of IGF-I mRNA. The expression of genes encoding IGF-IR, IR and IGFBP-2 in the oviduct exhibited a similar developmental change to that of IGF-I. These results suggest that IGF-I mainly works in an autocrine and/or paracrine manner in the oviduct during the development of this organ. The findings of the present study provide further evidence of an important role for IGF system in the development and function of the avian reproductive system.

Peripheral Thyroid Hormone Dynamics in Precocial and Altricial Avian Development1

SYNOPSIS. Precocial and altricial birds have distinctly different patterns of general ontogeny and metabolic/thermoregulatory development. In my laboratory, we have studied the development of thyroid function in Japanese quail ( Coturnix japonica ) and Ring doves ( Streptopelia risoria ) as examples of precocial and altricial development, respectively. In this paper, I review the literature and our work on the factors that influence peripheral hormone dynamics in birds. The first section of the paper describes adult peripheral thyroid function to set the stage for the developmental picture. Thyroid development is divided into two phases: Phase I, in which the thyroid gland develops functional capacity but there is low thyroid activity in the periphery, and Phase II, in which peripheral thyroid function increases and approaches adult levels. In precocial development Phase I occurs during embryonic life and Phase II begins at the perinatal period. In altricial development, the pattern of thyroid functional development is different and delayed. Peripheral thyroid hormone patterns in both developmental modes are discussed with reference to the factors that determine their dynamics: hormone availability from the thyroid gland, total serum hormone concentrations, the roles of serum binding proteins in regulating freehormone concentrations, hormone turnover and excretion, hormone receptors and thyroid hormone metabolism, especially extrathyroidal production of triiodothyronine from thyroxine.

The nature of thyrotropin stimulation of thyroid function in Japanese quail: Prolonged thyrotropin exposure is necessary to increase thyroidal 125I uptake

1. 1. Single injections of thyrotropin (TSH) increase serum T 4 and thyroidal 32P uptake but not thyroidal 125I uptake regardless of dosage, exposure time or age. Chronic TSH exposure, with 3 or more days of injection, does increase thyroidal 125I uptake. 2. 2. Studies using iodine (I) supplementation indicated that the increased thyroidal radioiodine uptakes seen with chronic TSH administration were not due to an I deficiency in the thyroid resulting from high hormone release. 3. 3. Labeled and unlabeled experiments comparing the effects of single vs. multiple injections of TSH were used to describe the effects of TSH on hormone release, hormone production and thyroidal I uptake.

Adrenocortical hormones and reproductive function in Japanese quail

Adrenocortical hormones and reproductive function in Japanese quail

Thyroid function in embryonic and perinatal Japanese quail.

Abstract Thyroid function in Japanese quail embryos is similar to that of domestic fowl embryos, suggesting the existence of a common pattern of thyroid development in precocial birds, regardless of differences in body size. From 10 to 15 days of incubation there are steady increases in the capacity for hormone production and release, but circulating triiodothyronine (T 3 ) and thyroxine (T 4 ) concentrations are low. During the perinatal period hormone secretion rises sharply. Serum concentrations of both T 3 and T 4 are significantly higher in embryos that have penetrated the chorioallantoic membrane than in ones that have not. Thus high thyroid hormone concentrations are associated with the beginning of pulmonary respiration and the high metabolic demands of the hatching process.

Feedback regulation of testicular function in Japanese quail: Testosterone implants in the hypothalamus and adenohypophysis

A possible inhibitory feedback control, by testicular sterooids, of gonadotropin release from the adenohypophysis was tested in adult breeding Japanese quail. Implantation of small pellets of testosterone propionate:charcoal (1:1) into medial or paramedial position in the ventral hypothalamus or adenohypophysis results in (a) testicular regression, (b) regression of the cloacal gland, and (c) a very low level of assayable pituitary gonadotropins. Implants located more anteriorly in the ventral hypothalamus in general result in a greater reduction of testicular weight and diameter of the seminiferous tubules than implants located in more posterior regions of the ventral hypothalamus; implants in both regions are equally effective in causing regression of the cloacal gland. That these effects are specific actions of testosterone, not indirect effects of a physical lesion in the ventral hypothalamus is supported by the findings that (a) implants of cholesterol:charcoal (1:1) in similar locations in the ventral infundibular region have no demonstrable effect on the testes or the cloacal gland, and (b) implants of testosterone propionate:charcoal or glass capillaries filled with crystalline testosterone propionate have only a temporary inhibitory effect on testicular and cloacal gland function; the activities of both these organs return (within 34 days) to near-normal levels despite the persistence of the implant in the brain. Implants in more dorsal regions of the infundibular nuclear complex, in the preoptic and/or supraoptic regions of the hypothalamus, in other regions of the hypothalamus, in the epithalamus and in the forebrain have no effect on testicular weight or functional activity of the cloacal gland; implants of testosterone cause in every bird, a slight reduction in diameter of the seminiferous tubules and in assayable pituitary gonadotropins.

Hypothalamic regulation of testicular function in Japanese quail.

Some of the components of the system that controls the function of the testes of the Japanese quail were identified by means of midline or bilateral electrolytic or radio-frequency coagulation of various regions of the hypothalamus. The destruction of two identifiable regions of the ventral hypothalamus resulted in different forms of testicular dysfunction. Extensive medial or bilateral damage to the infundibular nuclear complex, ventral regions thereof (including the tuberal nuclei), the entire median eminence or its posterior division resulted in regression of both the gametogenic and endocrine components of the testis and regression of the cloacal gland, an anal gland known to depend on testosterone for normal function. Damage to more anterodorsal regions of the infundibular nuclear complex resulted, in a single bird, in regression of the seminiferous tubules, but had no noticeable effect on the cells of Leydig; the cloacal gland of this bird, although reduced somewhat in size, appeared histologically active. Unilateral damage to the infundibular nuclear complex or the median eminence, or bilateral destruction of the antero—or posteroventral portions of the infundibular nuclear complex did not affect testicular function. The differing testicular dysfunctions are discussed in relation to the release of LH and FSH from the adenohypophysis.