International Review of Cytology

1. Auflage 2002
ISBN: 978-0-08-048919-3
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, Band Volume 218, 265 Seiten

Reihe: International Review of Cell and Molecular Biology

International Review of Cytology presents current advances and comprehensive reviews in cell biology-both plant and animal. Articles address structure and control of gene expression, nucleocytoplasmic interactions, control of cell development and differentiation, and cell transformation and growth. Authored by some of the foremost scientists in the field, each volume provides up-to-date information and directions for future research. - Authored by some of the foremost scientists in the field - Provides up-to-date information and directions for future research - Valuable reference material for advanced undergraduates, graduate students and professional scientists

Autoren/Hrsg.

Inhaltsverzeichnis

1;Front Cover;1
2;International Review of Cytology: A Survey of Cell Biology;4
3;Copyright Page;5
4;Contents;6
5;Contributors;8
6;Chapter 1. Involvement of Homeobox Genes in Early Body Plan of Monocot;10
6.1;I. Introduction;10
6.2;II. Plant Homeobox Genes;11
6.3;III. SAM Formation and knox Gene Expression during Early Embryogenesis in Monocots;22
6.4;IV. SAM Maintenance and knox Genes after SAM Formation;34
6.5;V. Concluding Remarks;37
6.6;References;37
7;Chapter 2. Telomeres in Mammalian Male Germline Cells;46
7.1;I. Introduction;46
7.2;II. Telomeres in Somatic and Germline Cells;47
7.3;III. Telomere Proteins and Chromatin Structure;62
7.4;IV. Concluding Remarks;69
7.5;References;71
8;Chapter 3. Evolutionary Aspects of Cellular Communication in the Vertebrate Hypothalamo–Hypophysio–Gonadal Axis;78
8.1;I. Introduction;78
8.2;II. Functional Morphology of Hypothalamal–Hypophysial–Gonadal Axis;79
8.3;III. Requirement of Local Control Mechanisms in Gonads;98
8.4;IV. Local Factors and Proto-Oncogene Activation in Gonads;102
8.5;V. Communication via GnRH: An Evolutionary Track;119
8.6;VI. Concluding Remarks;125
8.7;References;126
9;Chapter 4. Non-coding Ribonucleic Acids—A Class of Their Own?;152
9.1;I. Introduction;152
9.2;II. Non-coding RNAs in Microorganisms, Plants, and Invertebrates;153
9.3;III. Non-coding RNAs in Vertebrates;169
9.4;IV. Conclusions;210
9.5;References;212
10;Chapter 5. Three-Dimensional Progression of Programmed Death in the Rice Coleoptile;230
10.1;I. Introduction;230
10.2;II. The Coleoptile of Rice Plants;234
10.3;III. Cell Death;237
10.4;IV. Cell Death Progression in the Coleoptile;255
10.5;V. Concluding Remarks;260
10.6;References;262
11;Index;268

Leseproben

Involvement of Homeobox Genes in Early Body Plan of Monocot
Momoyo Ito; Yutaka Sato; Makoto Matsuoka    BioScience Center, Nagoya University, Chikusa, Nagoya 464-8601, Japan Abstract
Homeobox genes are known as transcriptional regulators that are involved in various aspects of developmental processes in many organisms. In plants, many types of homeobox genes have been identified, and mutational or expression pattern analyses of these genes have indicated the involvement of several classes of homeobox genes in developmental processes. The fundamental body plan of plants is established during embryogenesis, whereas morphogenetic events in the shoot apical meristem (SAM) continue after embryogenesis. Knotted1-like homeobox genes (knox genes) are preferentially expressed in both the SAM and the immature embryo. Therefore, these genes are considered to be key regulators of plant morphogenesis. In this review, we discuss the regulatory role of knox genes and other types of homeobox genes in SAM establishment during embryogenesis and SAM maintenance after embryogenesis, mainly in rice. KEY WORDS Embryogenesis Homeobox knox monocot Rice Shoot apical meristem I Introduction
The homeobox, which is characterized by conserved DNA sequence of 180 bp, encodes a 60-amino acid protein motif known as the homeodomain (HD). This structure consists of a helix-turn-helix DNA-binding motif, and thus the homeobox genes are thought to function as transcription factors (Gehring et al., 1994a,b; Gehring, 1987; Qian et al., 1989). Homeobox genes were originally identified in Drosophila homeotic mutants, Antennapedia and bithorax, as the genes that control patterning in Drosophila development (McGinnis et al., 1984; Scott and Weiner, 1984). Since then, homeobox genes have been identified in many evolutionarily distant organisms, including animals, plants, and fungi. In higher plants, many homeobox genes have been found to play important roles in various developmental events, as is the case in animals (Chan et al., 1998). Angiosperms are subdivided into two classes: dicotyledonous (dicot) and monocotyledonous (monocot) plants. Arabidopsis is commonly used as a model plant of dicots, and maize and rice are used as model plants of monocots. Many molecular and genetic studies using these model plants have revealed the existence of mutually orthologous genes in the dicot and monocot genomes, and they are thought to share essentially common mechanisms for each phenomenon, including various developmental events. On the other hand, there are also many morphological differences between monocots and dicots, and these should be reflected in some differences in the developmental mechanisms. In this review, we first describe the general characteristics of plant homeobox genes and the involvement of homeobox (mainly knox) genes in early development of monocots. Particular attention is then given to the morphological differences in embryogenesis between monocots and dicots. II Plant Homeobox Genes
A Characteristics of the Plant Homeobox Gene Family
The first homeobox gene to be identified in plants was KNOTTED1 (KN1) from the maize Knotted1 (Kn1) mutant (Vollbrecht et al., 1991). Leaf blades of the Kn1 mutant exhibit abnormal arrangements of the lateral veins, sporadic outgrowths called knots, and ligule displacements. Kn1 is a dominant mutant, caused by ectopic expression of KN1 in leaves, that results in the disorganization of the developmental program of leaf blades (Table I) (Smith and Hake, 1994). Subsequent to the cloning of the KN1 gene from maize, many plant homeobox genes have been isolated from various plant species using library screening with previously identified gene or degenerate oligonucleotides deduced from HDs as probes (Ruberti et al., 1991; Mattsson et al., 1992; Schena and Davis, 1992, 1994; Carabelli et al., 1993; Gonzalez and Chan, 1993; Matsuoka et al., 1993; Boivin et al., 1994; Chan and Gonzalez, 1994; Feng and Kung, 1994; Kerstetter et al., 1994; Lincoln et al., 1994; Ma et al., 1994; Soderman et al., 1994; Baima et al., 1995; Dockx et al., 1995; Kawahara et al., 1995; Meissner and Theres, 1995; Tamaoki et al., 1995, 1997; Di Cristina et al., 1996; Granger et al., 1996; Hareven et al., 1996; Lu et al., 1996; Serikawa et al., 1996; Gonzalez et al., 1997; Meijer et al., 1997; Valle et al., 1997; Watillon et al., 1997; Janssen et al., 1998; Sato et al., 1998; Sentoku et al., 1998, 1999; Nishimura et al., 1999; Ingram et al., 2000), differential screening (Nadeau et al., 1996; Tornero et al., 1996; Ingram et al., 1999; Dong et al., 2000), mutant based cloning (Table I) (Rerie et al., 1994; Müller et al., 1995; Reiser et al., 1995; Schneeberger et al., 1995; Long et al., 1996; Chen et al., 1997; Muehlbauer et al., 1997;Parnis et al., 1997; Mayer et al., 1998; Kubo et al., 1999), and other methods (Bellmann and Werr, 1992; Schindler et al., 1993; Korfhage et al., 1994; Klinge et al., 1996). On the basis of sequence similarities in their HDs and the presence of additional distinctive domains outside of the HD, plant homeobox genes are subdivided into several families: knox, HD-ZIP, glabra2, PHD-finger, BELL1, and WUSCHEL-type (Chan et al., 1998). The characteristic structure and functions of each of these plant homeobox gene families are described below (Fig. 1). Table I List of Homeobox Mutants and Their Phenotypes in Plants Kn1 (Knottedl) Maize Dominant Knots on leaves, blade-sheath boundary displacement knox Freeling and Hake, 1985
Vollbrecht et al., 1991 Kn1 Maize Recessive Arrested shoot development, reduced tassel branches, fewer spiklets knox Kerstetter et al., 1997
Vollbrecht et al., 2000 Rs1 (Roughsheath1) Maize Dominant Dwarf plants, sheath mesophyll overgrowth, blade-sheath boundary displacement knox Becraft and Freeling, 1994
Schneeberger et al., 1995 Gn1 (Gnarleyl/knox4) Maize Dominant Shortened internode (dwarf plants), sheath mesophyll overgrowth, blade-sheath boundary displacement knox Foster et al., 1999a
Foster et al., 1999b Lg4 (Liguleless4/knox5,11) Maize Dominant Blade into sheath transformation knox Fowler and Freeling, 1996 Lg3 (Liguleless3) Maize Dominant Blade into sheath transformation knox Fowler and Freeling, 1996
Fowler et al., 1996
Muehlbauer et al., 1997 d6 (OSH15) Rice Recessive Shortened intemode (dwarf plants), cell identity defects knox Sato et al., 1999 Hooded Barley Dominant Extra flower on the lemma knox Müller et al., 1995 stm (shootmeristemless) Arabidopsis Recessive Arrested shoot development, abnormal floral organ number knox Barton and Poethig, 1993 Long et al., 1996 Tkn2/Let6 Tomato Dominant Supercompound leaves, ectopic shoots knox Chen et al., 1997
Janssen et al., 1998
Parnis et al., 1997 ifl1 (interfascicular fiberless1) Arabidopsis Recessive Disruptted interfascicular fiber differentiation HD-ZIP Zhong et...