Zhang C, Cotter M, Lawton A, Oakley B, Wong L, Zeng Q
Department of Biology, University of Michigan, Ann Arbor 48109, USA.
Differentiation. 1995 Oct;59(3):155-62. doi: 10.1046/j.1432-0436.1995.5930155.x.
All or nearly all intragemmal (elongated) cells of rat taste buds were immunopositive for keratins 7, 8, and 19. In contrast, keratin 18 was detected in 19 +/- 5 cells per taste bud (mean +/- sd), or about 25% of the intragemmal cells. During taste bud development keratins 7, 8, and 19 were evident initially in polygonal cells and later in elongated taste cells. Keratin 8 appeared in vallate taste cells at P0 (postnatal day 0), followed by keratins 7 and 19 at P1, and keratin 18 at P2-P3. Keratin 18 was always limited to elongated cells. The assemblage of elongated taste cells comprising a taste bud began with a single elongated cell, rather than with the synchronous elongation of a cluster of cells. Developmental errors were observed at P2-P3, e.g., some vallate taste cells had a misoriented axis. In order to study the pace of keratin differentiation during cell turnover we injected bromodeoxyuridine (BrdU) into adult rats to monitor taste cell age. Keratin-19-positive intragemmal cells differentiated within 1 day. In contrast, keratin 18 was first detected in cells aged 3 days. Hence, both in taste cell development and replacement, keratin 18 was restricted to the older cells; it was the last taste cell keratin to become expressed during differentiation.
大鼠味蕾中所有或几乎所有的味蕾内（细长型）细胞对角蛋白7、8和19呈免疫阳性。相比之下，每个味蕾中可检测到19±5个角蛋白18阳性细胞（平均值±标准差），约占味蕾内细胞的25%。在味蕾发育过程中，角蛋白7、8和19最初在多边形细胞中可见，随后在细长型味觉细胞中出现。角蛋白8在出生后第0天（P0）出现在轮廓乳头味觉细胞中，随后角蛋白7和19在P1出现，角蛋白18在P2 - P3出现。角蛋白18始终局限于细长型细胞。构成味蕾的细长型味觉细胞的聚集始于单个细长型细胞，而非一群细胞的同步伸长。在P2 - P3观察到发育异常，例如，一些轮廓乳头味觉细胞的轴取向错误。为了研究细胞更新过程中角蛋白分化的速度，我们向成年大鼠注射溴脱氧尿苷（BrdU）以监测味觉细胞的年龄。角蛋白19阳性的味蕾内细胞在1天内分化。相比之下，角蛋白18首次在3日龄的细胞中检测到。因此，在味觉细胞发育和替换过程中，角蛋白18都局限于较老的细胞；它是分化过程中最后表达的味觉细胞角蛋白。
