CLONING AND CHARACTERIZATION OF MYOSIN-RELATED CDNAS FROM XENOPUS LAEVIS

为了了解非洲爪哇叉头蛋白(Xfkh3)的作用 在分裂前中胚层的分化中，我曾尝试 过表达和错误表达该蛋白的方法是在 2细胞期胚胎的两个卵裂球的动物极区。 分别注射0.25、0.5和1 ng的mRNA。在阶段8，动物帽子是 解剖培养，直到同胞胚胎发育到尾芽期 激活素的存在或不存在。尽管错误地表达了 尽管如此，信息本身并不能在动物的帽子中诱导任何肌肉， 激活素对肌肉的诱导作用不受抑制。对这些问题的进一步分析 结果目前正在进行中。 通过整装原位杂交，我已经定位了分布 非肌肉肌球蛋白重链B(Bhatia-Dey等人，Proc. 娜塔莉。阿卡德。SCI。美国90,2856,1993)使用包括以下部分的探测器 杆子和整个3‘UTR。文字记录被表达出来 然而，在囊胚期和原肠胚期胚胎中普遍存在 21，转录本开始定位于前部 胚胎，尤指发育中的眼睛和完全分化的胚胎 前体节。在尾芽早期，转录产物变得更多 集中在分化的体节和眼睛中。无表情 在有丝分裂前的中胚层中检测到。在游泳的蝌蚪中， 转录本定位于分化的体节、眼睛和 颧弓。使用来自非洲爪哇类似区域的探测器 非肌肉肌球蛋白重链A，未检测到定位转录本 在整个胚胎发育过程中。然而，Northern分析，使用相同的 探针，在发育过程中检测到2个转录本。7.5kb的文字记录 在从未受精卵到游泳的整个胚胎发生过程中都被检测到 在蝌蚪和一些成体组织中。另一份8.3 kb的文字记录 首先在阶段15/16左右检测到，峰值在阶段25到30之间， 在游泳的蝌蚪中逐渐减少，不再在 47期胚胎。初步分析表明，较大的 转录本是由于不同的多聚腺苷作用而产生的。

In order to understand the role of the Xenopus forkhead protein (Xfkh3) in the differentiation of presomitic mesoderm, I have tried to overexpress and misexpress this protein by injecting synthetic mRNA in the animal pole region of both blastomeres of 2 cell stage embryos. 0.25, 0.5 and 1 ng of mRNA was injected. At stage 8, animal caps were dissected and cultured until sibling embryos reached tailbud stage in the presence or absence of activin. Although misexpression of the message by itself does not induce any muscle in the animal caps, still, muscle induction by activin is not inhibited. Further analysis of these results is currently under progress. By whole mount in situ hybridization, I have localized the distribution of Xenopus nonmuscle myosin heavy chain B (Bhatia-Dey et al., Proc. Natl. Acad. Sci. USA 90, 2856, 1993) using a probe that comprises part of the rod and the entire 3' UTR. The transcript is expressed ubiquitously in blastula and gastrula stage embryos, however, at stage 21, the transcripts begin to localize in the anterior part of the embryo, especially in the developing eye and fully differentiated anterior somites. At early tailbud stage, the transcripts become more concentrated in differentiated somites and in the eye. No expression is detected in the presomitic mesoderm. In swimming tadpoles, the transcripts are localized in differentiated somites, the eye and the branchial arches. Using a probe from a similar region of Xenopus nonmuscle myosin heavy chain A, no localized transcripts were detected throughout embryogenesis. However, Northern analysis, using the same probe, detected 2 transcripts during development. A 7.5 kb transcript is detected throughout embryogenesis from unfertilized eggs to swimming tadpoles and in a number of adult tissues. Another 8.3 kb transcript is first detected around stage 15/16, peaks between stage 25 to 30, gradually decreases in swimming tadpoles and is no longer detected in stage 47 embryos. Preliminary analysis suggests that the larger transcript arises due to differential polyadenylation.