TY - JOUR
T1 - Aspects of vertebrate gustatory phylogeny
T2 - Morphology and turnover of chick taste bud cells
AU - Ganchrow, Judith R.
AU - Ganchrow, Donald
AU - Royer, Suzanne M.
AU - Kinnamon, John C.
PY - 1993/10/1
Y1 - 1993/10/1
N2 - The taste bud is a receptor form observed across vertebrates. The present report compares chick taste buds to those of other vertebrates using light and electron microscopy. Unlike mammals, but common to many modern avians, the dorsal surface of chick anterior tongue lacks taste papillae and taste buds. Ultrastructurally, chick buds located in the anterior floor of the mouth (as in some reptiles and amphibians) and palate contain dark, intermediate, light, and basal cell types. Dark, intermediate, and light cells extend microvilli into intragemmal lumina and pores communicating with the oral cavity. As specialized features, dark cell apices lack dense granules and exhibit short microvilli relative to light and intermediate cells. Dark cell cytoplasmic fingers envelop intragemmal nerve fibers and cells as in other species, and sometimes contain abundant clear vesicles. Nerve profile expansions often are located adjacent to dark, intermediate, and light cell nuclei. Classical afferent synaptic contacts are rarely observed. Taste cell turnover is suggested by mitotic and degenerating figures in chick buds. In addition, tritiated thymidine injected into hatchlings, whose anterior mandibular oral taste bud population approximates that in adults, reveals a turnover rate of about 4.5 days. This is about half that observed in altricial mammals, reflecting a species difference or developmental factor in precocial avians. It is concluded that chick taste buds exhibit morphologic features common to other vertebrate buds with specializations reflecting the influences of niche, glandular relations, and/or age. © 1993 Wiley‐Liss, Inc.
AB - The taste bud is a receptor form observed across vertebrates. The present report compares chick taste buds to those of other vertebrates using light and electron microscopy. Unlike mammals, but common to many modern avians, the dorsal surface of chick anterior tongue lacks taste papillae and taste buds. Ultrastructurally, chick buds located in the anterior floor of the mouth (as in some reptiles and amphibians) and palate contain dark, intermediate, light, and basal cell types. Dark, intermediate, and light cells extend microvilli into intragemmal lumina and pores communicating with the oral cavity. As specialized features, dark cell apices lack dense granules and exhibit short microvilli relative to light and intermediate cells. Dark cell cytoplasmic fingers envelop intragemmal nerve fibers and cells as in other species, and sometimes contain abundant clear vesicles. Nerve profile expansions often are located adjacent to dark, intermediate, and light cell nuclei. Classical afferent synaptic contacts are rarely observed. Taste cell turnover is suggested by mitotic and degenerating figures in chick buds. In addition, tritiated thymidine injected into hatchlings, whose anterior mandibular oral taste bud population approximates that in adults, reveals a turnover rate of about 4.5 days. This is about half that observed in altricial mammals, reflecting a species difference or developmental factor in precocial avians. It is concluded that chick taste buds exhibit morphologic features common to other vertebrate buds with specializations reflecting the influences of niche, glandular relations, and/or age. © 1993 Wiley‐Liss, Inc.
KW - Chickens
KW - EM
KW - Gustation
KW - HVEM
KW - Taste cell turnover
KW - Tritiated thymidine
UR - http://www.scopus.com/inward/record.url?scp=0027248047&partnerID=8YFLogxK
U2 - 10.1002/jemt.1070260204
DO - 10.1002/jemt.1070260204
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AN - SCOPUS:0027248047
SN - 1059-910X
VL - 26
SP - 106
EP - 119
JO - Microscopy Research and Technique
JF - Microscopy Research and Technique
IS - 2
ER -