Photobiomodulation of avian embryos by red laser

Quail allantoic endoderm was implanted into the presumptive digestive-tract area of chick embryos, and the differentiation of the endoderm was examined morphologically and immunocytochemically with antisera against pepsinogens and sucrase. The allantoic endoderm was incorporated into the host digestive organs. It often became continuous with the host endoderm and formed a chimaeric digestive-tract epithelium. It differentiated morphologically into the epithelium of the digestive organ into which it was incorporated, showing the morphological inductive ability in situ of the digestive-tract mesenchyme against the allantoic endoderm. However, the allantoic endoderm did not produce pepsinogens even when it was incorporated into the host proventricular mesenchyme and formed well-developed proventricular glands. This result indicates that the heterotypic morphogenesis of the allantoic endoderm is not necessarily accompanied by the heterotypic cytodifferentiation. In contrast, the anti-sucrase antiserum-reactive cells often differentiated in the allantoic endoderm incorporated into not only the intestine but also other organs. This confirmed our previous observation that the allantoic endoderm has a tendency to differentiate into the intestinal epithelium in the heterologous environment.

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Heterotopic transplantation of presumptive placodal ectoderm changes the fate of sensory neuron precursors

Development ◽

10.1242/dev.119.1.263 ◽

1993 ◽

Vol 119 (1) ◽

pp. 263-276 ◽

Cited By ~ 10

Author(s):

K.S. Vogel ◽

A.M. Davies

Keyword(s):

Growth Rate ◽

Sensory Neurons ◽

Chicken Embryo ◽

Neurite Growth ◽

Heterotopic Transplantation ◽

Growth And Survival ◽

Avian Embryos ◽

Nodose Ganglia ◽

Innervation Patterns

The placode-derived cranial sensory neurons of the vestibular and nodose ganglia in avian embryos exhibit differences in neurite growth rate and the duration of neurotrophin-independent survival in vitro that arise prior to gangliogenesis and target contact (Davies, A. M. (1989) Nature 337, 553–555; Vogel, K. S. and Davies, A. M. (1991) Neuron 7, 819–830). To ascertain the state of commitment of presumptive placodal ectoderm to differentiate into neurons of the vestibular or nodose type, we performed heterotopic transplantation of labelled presumptive placodal ectoderm at E1.5 in the chicken embryo. We then assayed transplant-derived neurons for hindbrain innervation patterns, neurite growth and survival at E3.5. We show that presumptive placodal ectoderm is not determined to give rise to neurons of the vestibular or nodose phenotype at E1.5. Explantation of presumptive placodal ectoderm at E1.5 showed that this ectoderm is also not specified to differentiate into neurons at this stage. In addition, we demonstrate that non-neurogenic ectoderm from the trunk can give rise to nodose-type neurons when transplanted heterotopically to the nodose region.

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The acoustocardiogram: a noninvasive method for measuring heart rate of avian embryos in ovo

Journal of Applied Physiology ◽

10.1152/jappl.1990.69.4.1546 ◽

1990 ◽

Vol 69 (4) ◽

pp. 1546-1548 ◽

Cited By ~ 22

Author(s):

H. Rahn ◽

S. A. Poturalski ◽

C. V. Paganelli

Keyword(s):

Heart Rate ◽

Low Cost ◽

Noninvasive Method ◽

In Ovo ◽

Avian Embryos ◽

Condenser Microphone ◽

Avian Eggs

A method is presented for measuring the heart rate of avian eggs noninvasively during the last half of incubation. The technique involves briefly placing an egg in tightly sealed vessel containing an inexpensive condenser microphone. The amplified output of the microphone, termed the acoustocardiogram (ACG), is nearly sinusoidal in shape and synchronous with the electrocardiogram. The ACG can also be obtained by mounting the microphone directly on the shell with Plasticine. The method offers advantages over previously described techniques in simplicity, low cost, and noninvasiveness.

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