Showing papers by "Douglas A. Melton published in 1986"
TL;DR: The DNA sequence of a Xhox‐1 cDNA is determined and this allows us to predict the complete sequences of a vertebrate homeobox protein.
Abstract: We have isolated a Xenopus genomic clone (Xhox-1) that contains two homeoboxes, at least one of which is highly conserved in vertebrates. Two transcripts are derived from Xhox-1 and these are present from early in development through swimming tadpole stages. A detailed analysis of one of the genes shows that it is expressed maternally and that transcription from the zygotic genome begins at mid-gastrulation. Examination of exogastrula shows that the expression of these genes does not depend on neural induction. We have determined the DNA sequence of a Xhox-1 cDNA and this allows us to predict the complete sequence of a vertebrate homeobox protein. Synthetic mRNAs made from this cDNA are translated efficiently in Xenopus oocytes where the homeobox protein localizes to the oocyte nucleus.
109 citations
TL;DR: It is likely that many genes that control vertebrate development will have to be identified by other means, because it is not possible to perform exhaustive screens for mutations that affect developmental processes.
Abstract: In general, it is difficult to identify genes that play critical roles in developmental decisions in vertebrates because it is not possible to perform exhaustive screens for mutations that affect developmental processes. While some genes have been identified and analysed by conventional genetic methods, for example the mouse T locus (Bennett, 1975) or the axolotl o mutation (Brothers, 1976), it is likely that many genes that control vertebrate development will have to be identified by other means. In recent years, two methods for identifying such genes have been utilized. First, genes have been selected for study because they are expressed at a particular time or place during embryogenesis. For example, genes that are expressed only during gastrulation (Sargent & Dawid, 1983; Krieg & Melton, 1985) or at the cellular blastoderm stage (Roark, Mahoney, Graham & Lengyel, 1985) have been cloned and there are numerous examples of genes being studied because they are expressed in some, but not all tissues (e.g. Lynn et al . 1983) or are spatially localized within single cells (Jeffery, Tomlinson & Brodeurer, 1983; King & Barklis, 1985; Rebagliati, Weeks, Harvey & Melton, 1985).
7 citations