In ovo green light photostimulation during the late incubation stage affects somatotropic axis activity.

Targeted green light photostimulation during the last stage of broiler incubation increases expression of the somatotropic axis. The purpose of this study was to further shorten the in ovo green light photostimulation and determine the critical age for photostimulation in broilers embryos, as a future strategy for broiler incubation. Fertile broilers eggs (n = 420) were divided into 5 treatment groups. The first group was incubated under standard conditions (in the dark) as the negative control group. The second was incubated under intermittent monochromatic green light using light-emitting diode lamps with an intensity of 0.1 W/m2 at shell level from embryonic day (ED) 0 of incubation until hatch, as a positive control. The third, fourth, and fifth groups were incubated under intermittent monochromatic green light from ED 15, 16, and 18 of incubation, respectively, until hatch. All treatment groups showed elevated somatotropic axis expression compared with the negative control, with the group incubated under monochromatic green light from ED 18 until hatch showing results closest to the positive control. This suggests that broiler embryos can be exposed to in ovo green light photostimulation from a late stage of incubation (when transferring the eggs to the hatchery) and exhibit essentially the same outcome as obtained by photostimulation during the entire incubation period.

A combination of chicken embryo extract and a nutritional supplement protect a rat model of aging against d-galactose-induced dysfunction of mitochondria and autophagy.

The aging process is usually associated with increased oxidative stress and deficiency of tissues and organs, which causes a decline in the life quality of individuals. Some anti-oxidant factors derived from foods have been implicated in delaying senescence and sustaining health. The present study aimed to assess the anti-aging effects and underlying mechanism of the combined application of chicken embryo (CE) extract and a nutritional mixture (NM) of 52 ingredients on the aging process of d-galactose (d-gal)-induced rats. After 90 days of treatment, we observed that CE plus NM administration significantly improved the body weight, visceral indices and histological damage of aging rats. The use of CE or NM alone exhibited similar effects, but was not as effective as the combined use of CE and NM. In addition, the additional nutrients promoted the mitochondrial function of d-galactose-induced rats. With CE + NM supplementation, cells from senescent rats showed decreased accumulation of reactive oxygen species (ROS), increased levels of mitochondrial membrane potential, elevated numbers of mitochondria, and morphological changes towards normalization compared to the un-treated group. Furthermore, autophagosomes and autophagy-related proteins were up-regulated in aging rats upon exposure to CE + NM. Interestingly, we also found that the protein extracts of CE have similar effects to CE. These results indicate the critical role played by CE + NM in promoting the function of mitochondria and autophagy, therefore regulating the aging process in rats. Our study provides a novel compound design of nutritional support to achieve an optimal nutritional status for anti-oxidation and slowing of aging.

The effect of dietary selenium source and level on the uptake of selenium by developing chick embryos.

We studied the effect of dietary source (organic or inorganic) and level of Se on the Se uptake of chick embryos. After receiving a low-Se diet for 16 wk, 126 Leghorn laying hens were randomly assigned to one of seven dietary treatments. Treatments consisted of feeding a low-Se basal diet alone or with one of three levels of added Se (0.1,0.2, or 0.3 mg/kg Se) supplied by sodium selenite or Se-enriched yeast. Fertile eggs were collected after 33 d of feeding the experimental diets. Eggs were subjected to no incubation or incubation for 5, 10, 15, or 20 d. Non-incubated eggs were separated, and the yolk and albumen were assayed separately for Se. Incubated eggs were separated into the embryo and extra-embryonic portions, which were assayed separately for Se. Se concentrations of the yolk and albumen were significantly different among dietary treatments. Compared with eggs from hens fed sodium selenite, yolk and albumen Se concentrations were higher in eggs from hens fed Se yeast. Embryonic and extra-embryonic Se concentrations were higher in eggs from hens fed Se yeast than eggs from hens fed sodium selenite. The largest increase in embryonic Se concentration was observed during Days 10 to 15 of incubation. It was concluded that Se source and dietary inclusion level influenced the Se concentration of portions of developing embryonated eggs and that embryonic Se concentration changed during incubation.

Egg yolk polyunsaturated fatty acids and vitamin E content alters the tocopherol status of hatched chicks.

Polyunsaturated fatty acid composition and tocopherol status of newly hatched chicks from hens fed diets containing 3.5% menhaden (MO), flax (LO), palm (PO), or sunflower oils (SO) with (+T) or without tocopherols were examined. Addition of tocopherols increased (P < 0.05) the tocopherol content of eggs and hatched chick tissues. The total tocopherol content was lower (P < 0.05) in MO + T eggs than in LO + T, PO + T, or SO + T eggs. The tocopherol content of chick tissues was as follows liver > plasma > brain. Among the tocopherol-supplemented group, The MO + T chicks incorporated the lowest (P < 0.05) level of total tocopherols in the liver and plasma when compared to chicks hatched from LO + T, PO + T, or SO + T eggs. Brain tissue incorporated the lowest level of tocopherols among all the tissues examined. The fourfold increase in egg tocopherols did not alter the brain tocopherol in MO + T, LO + T, or SO + T chicks. In the MO and LO eggs, there was a significant increase (P < 0.05) in n-3 PUFA when compared with SO or PO eggs. The C22:6 n-3 content in liver and plasma was higher (P < 0.05) in chicks hatched from MO and LO eggs than in chicks hatched from PO or SO eggs. The brain tissue of MO chicks incorporated the highest (P < 0.05) levels of C22:6 n-3 followed by the brain tissue of LO chicks.

Developmental expression and distinctive tyrosine phosphorylation of the Eph-related receptor tyrosine kinase Cek9.

Cek9 is a receptor tyrosine kinase of the Eph subfamily for which only a partial cDNA sequence was known (Sajjadi, F.G., and E.B. Pasquale. 1993. Oncogene. 8:1807-1813). We have obtained the entire cDNA sequence and identified a variant form of Cek9 that lacks a signal peptide. We subsequently examined the spatio-temporal expression and tyrosine phosphorylation of Cek9 in the chicken embryo by using specific antibodies. At embryonic day 2, Cek9 immunoreactivity is concentrated in the eye, the brain, the posterior region of the neural tube, and the most recently formed somites. Later in development, Cek9 expression is widespread but particularly prominent in neural tissues. In the developing visual system, Cek9 is highly concentrated in areas containing retinal ganglion cell axons, suggesting a role in regulating their outgrowth to the optic tectum. Unlike other Eph-related receptors, Cek9 is substantially phosphorylated on tyrosine in many tissues at various developmental stages. Since autophosphorylation of receptor protein-tyrosine kinases typically correlates with increased enzymatic activity, this suggests that Cek9 plays an active role in embryonic signal transduction pathways.

Ontogeny of immunocytochemically demonstrable androgen- and androgen receptor-containing cells in the hypothalamus and adenohypophysis of the chick embryo.

Brain sections of male chick embryos, 6.5-18.5 days of age, were examined immunocytochemically for the presence of androgen- and androgen receptor-containing cells in the hypothalamus and adenohypophyseal pars distalis. Using antibodies (Ab) against both androgens (T-Ab) and the androgen receptor (AR-Ab), single- and double-immunostained cells were located in a total of five nuclei of the anterior-, mid-, and posterior-hypothalamus, as well as in the rostral and caudal lobes of the adenohypophyseal pars distalis. From Days 9.5-12.5, the mean number of androgen-immunostained cells within the hypothalamus and pars distalis increased significantly (P < 0.01), while from Days 12.5-18.5 there was no further statistically significant increase. The results of the present investigation support previous findings which suggest that in the chick embryo the negative feedback loop of the hypothalamo-adenohypophyseal-testicular (HATest) axis is functional by the 13th day of development (Woods et al., 1989a,b). They also agree with the observations of Wilson and Glick (1970) that in the male chick embryo testosterone organizes masculine mating behavior prior to Day 13.0.