Developmental biology

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Developmental biology is the study of the process by which animals and plants grow and develop. Developmental biology also encompasses the biology of regeneration, asexual reproduction, metamorphosis, and the growth and differentiation of stem cells in the adult organism.

Contents

Perspectives

The main processes involved in the embryonic development of animals are: tissue patterning (via regional specification and patterned cell differentiation); tissue growth; and tissue morphogenesis.

The development of plants involves similar processes to that of animals. However, plant cells are mostly immotile so morphogenesis is achieved by differential growth, without cell movements. Also, the inductive signals and the genes involved are different from those that control animal development.

Developmental processes

Cell differentiation

The Notch-delta system in neurogenesis (Slack Essential Dev Biol Fig 14.12a) Slack Essential Dev Biol Fig 14.12a.jpg
The Notch-delta system in neurogenesis (Slack Essential Dev Biol Fig 14.12a)

Cell differentiation is the process whereby different functional cell types arise in development. For example, neurons, muscle fibers and hepatocytes (liver cells) are well known types of differentiated cells. Differentiated cells usually produce large amounts of a few proteins that are required for their specific function and this gives them the characteristic appearance that enables them to be recognized under the light microscope. The genes encoding these proteins are highly active. Typically their chromatin structure is very open, allowing access for the transcription enzymes, and specific transcription factors bind to regulatory sequences in the DNA in order to activate gene expression. [1] [2] For example, NeuroD is a key transcription factor for neuronal differentiation, myogenin for muscle differentiation, and HNF4 for hepatocyte differentiation. Cell differentiation is usually the final stage of development, preceded by several states of commitment which are not visibly differentiated. A single tissue, formed from a single type of progenitor cell or stem cell, often consists of several differentiated cell types. Control of their formation involves a process of lateral inhibition, [3] based on the properties of the Notch signaling pathway. [4] For example, in the neural plate of the embryo this system operates to generate a population of neuronal precursor cells in which NeuroD is highly expressed.

Regeneration

Regeneration indicates the ability to regrow a missing part. [5] This is very prevalent amongst plants, which show continuous growth, and also among colonial animals such as hydroids and ascidians. But most interest by developmental biologists has been shown in the regeneration of parts in free living animals. In particular four models have been the subject of much investigation. Two of these have the ability to regenerate whole bodies: Hydra , which can regenerate any part of the polyp from a small fragment, [6] and planarian worms, which can usually regenerate both heads and tails. [7] Both of these examples have continuous cell turnover fed by stem cells and, at least in planaria, at least some of the stem cells have been shown to be pluripotent. [8] The other two models show only distal regeneration of appendages. These are the insect appendages, usually the legs of hemimetabolous insects such as the cricket, [9] and the limbs of urodele amphibians. [10] Considerable information is now available about amphibian limb regeneration and it is known that each cell type regenerates itself, except for connective tissues where there is considerable interconversion between cartilage, dermis and tendons. In terms of the pattern of structures, this is controlled by a re-activation of signals active in the embryo. There is still debate about the old question of whether regeneration is a "pristine" or an "adaptive" property. [11] If the former is the case, with improved knowledge, we might expect to be able to improve regenerative ability in humans. If the latter, then each instance of regeneration is presumed to have arisen by natural selection in circumstances particular to the species, so no general rules would be expected.

Embryonic development of animals

Generalized scheme of embryonic development. Slack "Essential Developmental Biology". Fig. 2.8. Slack Essential Dev Biol Fig 02-08.jpg
Generalized scheme of embryonic development. Slack "Essential Developmental Biology". Fig. 2.8.
The initial stages of human embryogenesis HumanEmbryogenesis.svg
The initial stages of human embryogenesis

The sperm and egg fuse in the process of fertilization to form a fertilized egg, or zygote. [12] This undergoes a period of divisions to form a ball or sheet of similar cells called a blastula or blastoderm. These cell divisions are usually rapid with no growth so the daughter cells are half the size of the mother cell and the whole embryo stays about the same size. They are called cleavage divisions.

Mouse epiblast primordial germ cells (see Figure: “The initial stages of human embryogenesis”) undergo extensive epigenetic reprogramming. [13] This process involves genome-wide DNA demethylation, chromatin reorganization and epigenetic imprint erasure leading to totipotency. [13] DNA demethylation is carried out by a process that utilizes the DNA base excision repair pathway. [14]

Morphogenetic movements convert the cell mass into a three layered structure consisting of multicellular sheets called ectoderm, mesoderm and endoderm. These sheets are known as germ layers. This is the process of gastrulation. During cleavage and gastrulation the first regional specification events occur. In addition to the formation of the three germ layers themselves, these often generate extraembryonic structures, such as the mammalian placenta, needed for support and nutrition of the embryo, [15] and also establish differences of commitment along the anteroposterior axis (head, trunk and tail). [16]

Regional specification is initiated by the presence of cytoplasmic determinants in one part of the zygote. The cells that contain the determinant become a signaling center and emit an inducing factor. Because the inducing factor is produced in one place, diffuses away, and decays, it forms a concentration gradient, high near the source cells and low further away. [17] [18] The remaining cells of the embryo, which do not contain the determinant, are competent to respond to different concentrations by upregulating specific developmental control genes. This results in a series of zones becoming set up, arranged at progressively greater distance from the signaling center. In each zone a different combination of developmental control genes is upregulated. [19] These genes encode transcription factors which upregulate new combinations of gene activity in each region. Among other functions, these transcription factors control expression of genes conferring specific adhesive and motility properties on the cells in which they are active. Because of these different morphogenetic properties, the cells of each germ layer move to form sheets such that the ectoderm ends up on the outside, mesoderm in the middle, and endoderm on the inside. [20] [21]

Schema of the development of the axial twist in vertebrates AxialTwistSchema.png
Schema of the development of the axial twist in vertebrates

Morphogenetic movements not only change the shape and structure of the embryo, but by bringing cell sheets into new spatial relationships they also make possible new phases of signaling and response between them. In addition, first morphogenetic movements of embryogenesis, such as gastrulation, epiboly and twisting, directly activate pathways involved in endomesoderm specification through mechanotransduction processes. [22] [23] This property was suggested to be evolutionary inherited from endomesoderm specification as mechanically stimulated by marine environmental hydrodynamic flow in first animal organisms (first metazoa). [24] Twisting along the body axis by a left-handed chirality is found in all chordates (including vertebrates) and is addressed by the axial twist theory. [25]

Growth in embryos is mostly autonomous. [26] For each territory of cells the growth rate is controlled by the combination of genes that are active. Free-living embryos do not grow in mass as they have no external food supply. But embryos fed by a placenta or extraembryonic yolk supply can grow very fast, and changes to relative growth rate between parts in these organisms help to produce the final overall anatomy.

The whole process needs to be coordinated in time and how this is controlled is not understood. There may be a master clock able to communicate with all parts of the embryo that controls the course of events, or timing may depend simply on local causal sequences of events. [27]

Metamorphosis

Developmental processes are very evident during the process of metamorphosis. This occurs in various types of animal. Well-known examples are seen in frogs, which usually hatch as a tadpole and metamorphoses to an adult frog, and certain insects which hatch as a larva and then become remodeled to the adult form during a pupal stage.

All the developmental processes listed above occur during metamorphosis. Examples that have been especially well studied include tail loss and other changes in the tadpole of the frog Xenopus, [28] [29] and the biology of the imaginal discs, which generate the adult body parts of the fly Drosophila melanogaster. [30] [31]

Plant development

Plant development is the process by which structures originate and mature as a plant grows. It is studied in plant anatomy and plant physiology as well as plant morphology.

Plants constantly produce new tissues and structures throughout their life from meristems [32] located at the tips of organs, or between mature tissues. Thus, a living plant always has embryonic tissues. By contrast, an animal embryo will very early produce all of the body parts that it will ever have in its life. When the animal is born (or hatches from its egg), it has all its body parts and from that point will only grow larger and more mature.

The properties of organization seen in a plant are emergent properties which are more than the sum of the individual parts. "The assembly of these tissues and functions into an integrated multicellular organism yields not only the characteristics of the separate parts and processes but also quite a new set of characteristics which would not have been predictable on the basis of examination of the separate parts." [33]

Growth

A vascular plant begins from a single celled zygote, formed by fertilisation of an egg cell by a sperm cell. From that point, it begins to divide to form a plant embryo through the process of embryogenesis. As this happens, the resulting cells will organize so that one end becomes the first root, while the other end forms the tip of the shoot. In seed plants, the embryo will develop one or more "seed leaves" (cotyledons). By the end of embryogenesis, the young plant will have all the parts necessary to begin its life.

Once the embryo germinates from its seed or parent plant, it begins to produce additional organs (leaves, stems, and roots) through the process of organogenesis. New roots grow from root meristems located at the tip of the root, and new stems and leaves grow from shoot meristems located at the tip of the shoot. [34] Branching occurs when small clumps of cells left behind by the meristem, and which have not yet undergone cellular differentiation to form a specialized tissue, begin to grow as the tip of a new root or shoot. Growth from any such meristem at the tip of a root or shoot is termed primary growth and results in the lengthening of that root or shoot. Secondary growth results in widening of a root or shoot from divisions of cells in a cambium. [35]

In addition to growth by cell division, a plant may grow through cell elongation. [36] This occurs when individual cells or groups of cells grow longer. Not all plant cells will grow to the same length. When cells on one side of a stem grow longer and faster than cells on the other side, the stem will bend to the side of the slower growing cells as a result. This directional growth can occur via a plant's response to a particular stimulus, such as light (phototropism), gravity (gravitropism), water, (hydrotropism), and physical contact (thigmotropism).

Plant growth and development are mediated by specific plant hormones and plant growth regulators (PGRs) (Ross et al. 1983). [37] Endogenous hormone levels are influenced by plant age, cold hardiness, dormancy, and other metabolic conditions; photoperiod, drought, temperature, and other external environmental conditions; and exogenous sources of PGRs, e.g., externally applied and of rhizospheric origin.

Morphological variation

Plants exhibit natural variation in their form and structure. While all organisms vary from individual to individual, plants exhibit an additional type of variation. Within a single individual, parts are repeated which may differ in form and structure from other similar parts. This variation is most easily seen in the leaves of a plant, though other organs such as stems and flowers may show similar variation. There are three primary causes of this variation: positional effects, environmental effects, and juvenility.

Evolution of plant morphology

Transcription factors and transcriptional regulatory networks play key roles in plant morphogenesis and their evolution. During plant landing, many novel transcription factor families emerged and are preferentially wired into the networks of multicellular development, reproduction, and organ development, contributing to more complex morphogenesis of land plants. [38]

Most land plants share a common ancestor, multicellular algae. An example of the evolution of plant morphology is seen in charophytes. Studies have shown that charophytes have traits that are homologous to land plants. There are two main theories of the evolution of plant morphology, these theories are the homologous theory and the antithetic theory. The commonly accepted theory for the evolution of plant morphology is the antithetic theory. The antithetic theory states that the multiple mitotic divisions that take place before meiosis, cause the development of the sporophyte. Then the sporophyte will development as an independent organism. [39]

Developmental model organisms

Much of developmental biology research in recent decades has focused on the use of a small number of model organisms. It has turned out that there is much conservation of developmental mechanisms across the animal kingdom. In early development different vertebrate species all use essentially the same inductive signals and the same genes encoding regional identity. Even invertebrates use a similar repertoire of signals and genes although the body parts formed are significantly different. Model organisms each have some particular experimental advantages which have enabled them to become popular among researchers. In one sense they are "models" for the whole animal kingdom, and in another sense they are "models" for human development, which is difficult to study directly for both ethical and practical reasons. Model organisms have been most useful for elucidating the broad nature of developmental mechanisms. The more detail is sought, the more they differ from each other and from humans.

Plants

Vertebrates

Invertebrates

Unicellular

Others

Also popular for some purposes have been sea urchins [48] [40] and ascidians. [49] For studies of regeneration urodele amphibians such as the axolotl Ambystoma mexicanum are used, [50] and also planarian worms such as Schmidtea mediterranea . [7] Organoids have also been demonstrated as an efficient model for development. [51] Plant development has focused on the thale cress Arabidopsis thaliana as a model organism. [52]

See also

Related Research Articles

Morphogenesis is the biological process that causes a cell, tissue or organism to develop its shape. It is one of three fundamental aspects of developmental biology along with the control of tissue growth and patterning of cellular differentiation.

<span class="mw-page-title-main">Evolutionary developmental biology</span> Comparison of organism developmental processes

Evolutionary developmental biology is a field of biological research that compares the developmental processes of different organisms to infer how developmental processes evolved.

<span class="mw-page-title-main">Cellular differentiation</span> Developmental biology

Cellular differentiation is the process in which a stem cell changes from one type to a differentiated one. Usually, the cell changes to a more specialized type. Differentiation happens multiple times during the development of a multicellular organism as it changes from a simple zygote to a complex system of tissues and cell types. Differentiation continues in adulthood as adult stem cells divide and create fully differentiated daughter cells during tissue repair and during normal cell turnover. Some differentiation occurs in response to antigen exposure. Differentiation dramatically changes a cell's size, shape, membrane potential, metabolic activity, and responsiveness to signals. These changes are largely due to highly controlled modifications in gene expression and are the study of epigenetics. With a few exceptions, cellular differentiation almost never involves a change in the DNA sequence itself. However, metabolic composition does get altered quite dramatically where stem cells are characterized by abundant metabolites with highly unsaturated structures whose levels decrease upon differentiation. Thus, different cells can have very different physical characteristics despite having the same genome.

<span class="mw-page-title-main">Blastulation</span> Sphere of cells formed during early embryonic development in animals

Blastulation is the stage in early animal embryonic development that produces the blastula. In mammalian development the blastula develops into the blastocyst with a differentiated inner cell mass and an outer trophectoderm. The blastula is a hollow sphere of cells known as blastomeres surrounding an inner fluid-filled cavity called the blastocoel. Embryonic development begins with a sperm fertilizing an egg cell to become a zygote, which undergoes many cleavages to develop into a ball of cells called a morula. Only when the blastocoel is formed does the early embryo become a blastula. The blastula precedes the formation of the gastrula in which the germ layers of the embryo form.

<span class="mw-page-title-main">Gastrulation</span> Stage in embryonic development in which germ layers form

Gastrulation is the stage in the early embryonic development of most animals, during which the blastula, or in mammals the blastocyst is reorganized into a two-layered or three-layered embryo known as the gastrula. Before gastrulation, the embryo is a continuous epithelial sheet of cells; by the end of gastrulation, the embryo has begun differentiation to establish distinct cell lineages, set up the basic axes of the body, and internalized one or more cell types including the prospective gut.

<span class="mw-page-title-main">Meristem</span> Type of plant tissue involved in cell proliferation

The meristem is a type of tissue found in plants. It consists of undifferentiated cells capable of cell division. Cells in the meristem can develop into all the other tissues and organs that occur in plants. These cells continue to divide until a time when they get differentiated and then lose the ability to divide.

<span class="mw-page-title-main">Paracrine signaling</span> Form of localized cell signaling

In cellular biology, paracrine signaling is a form of cell signaling, a type of cellular communication in which a cell produces a signal to induce changes in nearby cells, altering the behaviour of those cells. Signaling molecules known as paracrine factors diffuse over a relatively short distance, as opposed to cell signaling by endocrine factors, hormones which travel considerably longer distances via the circulatory system; juxtacrine interactions; and autocrine signaling. Cells that produce paracrine factors secrete them into the immediate extracellular environment. Factors then travel to nearby cells in which the gradient of factor received determines the outcome. However, the exact distance that paracrine factors can travel is not certain.

<span class="mw-page-title-main">Cell proliferation</span> Biological process of growth and division

Cell proliferation is the process by which a cell grows and divides to produce two daughter cells. Cell proliferation leads to an exponential increase in cell number and is therefore a rapid mechanism of tissue growth. Cell proliferation requires both cell growth and cell division to occur at the same time, such that the average size of cells remains constant in the population. Cell division can occur without cell growth, producing many progressively smaller cells, while cell growth can occur without cell division to produce a single larger cell. Thus, cell proliferation is not synonymous with either cell growth or cell division, despite these terms sometimes being used interchangeably.

<span class="mw-page-title-main">Regeneration (biology)</span> Biological process of renewal, restoration, and tissue growth

Regeneration in biology is the process of renewal, restoration, and tissue growth that makes genomes, cells, organisms, and ecosystems resilient to natural fluctuations or events that cause disturbance or damage. Every species is capable of regeneration, from bacteria to humans. Regeneration can either be complete where the new tissue is the same as the lost tissue, or incomplete after which the necrotic tissue becomes fibrotic.

Organogenesis is the phase of embryonic development that starts at the end of gastrulation and continues until birth. During organogenesis, the three germ layers formed from gastrulation form the internal organs of the organism.

Plant embryonic development, also plant embryogenesis is a process that occurs after the fertilization of an ovule to produce a fully developed plant embryo. This is a pertinent stage in the plant life cycle that is followed by dormancy and germination. The zygote produced after fertilization must undergo various cellular divisions and differentiations to become a mature embryo. An end stage embryo has five major components including the shoot apical meristem, hypocotyl, root meristem, root cap, and cotyledons. Unlike the embryonic development in animals, and specifically in humans, plant embryonic development results in an immature form of the plant, lacking most structures like leaves, stems, and reproductive structures. However, both plants and animals including humans, pass through a phylotypic stage that evolved independently and that causes a developmental constraint limiting morphological diversification.

<span class="mw-page-title-main">Morphogen</span> Biological substance that guides development by non-uniform distribution

A morphogen is a substance whose non-uniform distribution governs the pattern of tissue development in the process of morphogenesis or pattern formation, one of the core processes of developmental biology, establishing positions of the various specialized cell types within a tissue. More specifically, a morphogen is a signaling molecule that acts directly on cells to produce specific cellular responses depending on its local concentration.

<span class="mw-page-title-main">ABC model of flower development</span> Model for genetics of flower development

The ABC model of flower development is a scientific model of the process by which flowering plants produce a pattern of gene expression in meristems that leads to the appearance of an organ oriented towards sexual reproduction, a flower. There are three physiological developments that must occur in order for this to take place: firstly, the plant must pass from sexual immaturity into a sexually mature state ; secondly, the transformation of the apical meristem's function from a vegetative meristem into a floral meristem or inflorescence; and finally the growth of the flower's individual organs. The latter phase has been modelled using the ABC model, which aims to describe the biological basis of the process from the perspective of molecular and developmental genetics.

<span class="mw-page-title-main">Primordium</span> Organ in the earliest recognizable stage of embryonic development

A primordium in embryology, is an organ or tissue in its earliest recognizable stage of development. Cells of the primordium are called primordial cells. A primordium is the simplest set of cells capable of triggering growth of the would-be organ and the initial foundation from which an organ is able to grow. In flowering plants, a floral primordium gives rise to a flower.

<span class="mw-page-title-main">Plant morphology</span> Study of the structure of plants

Phytomorphology is the study of the physical form and external structure of plants. This is usually considered distinct from plant anatomy, which is the study of the internal!structure of plants, especially at the microscopic level. Plant morphology is useful in the visual identification of plants. Recent studies in molecular biology started to investigate the molecular processes involved in determining the conservation and diversification of plant morphologies. In these studies transcriptome conservation patterns were found to mark crucial ontogenetic transitions during the plant life cycle which may result in evolutionary constraints limiting diversification.

Within the field of developmental biology, one goal is to understand how a particular cell develops into a final cell type, known as fate determination. Within an embryo, several processes play out at the cellular and tissue level to create an organism. These processes include cell proliferation, differentiation, cellular movement and programmed cell death. Each cell in an embryo receives molecular signals from neighboring cells in the form of proteins, RNAs and even surface interactions. Almost all animals undergo a similar sequence of events during very early development, a conserved process known as embryogenesis. During embryogenesis, cells exist in three germ layers, and undergo gastrulation. While embryogenesis has been studied for more than a century, it was only recently that scientists discovered that a basic set of the same proteins and mRNAs are involved in embryogenesis. Evolutionary conservation is one of the reasons that model systems such as the fly, the mouse, and other organisms are used as models to study embryogenesis and developmental biology. Studying model organisms provides information relevant to other animals, including humans. While studying the different model systems, cells fate was discovered to be determined via multiple ways, two of which are by the combination of transcription factors the cells have and by the cell-cell interaction. Cells' fate determination mechanisms were categorized into three different types, autonomously specified cells, conditionally specified cells, or syncytial specified cells. Furthermore, the cells' fate was determined mainly using two types of experiments, cell ablation and transplantation. The results obtained from these experiments, helped in identifying the fate of the examined cells.

Important structures in plant development are buds, shoots, roots, leaves, and flowers; plants produce these tissues and structures throughout their life from meristems located at the tips of organs, or between mature tissues. Thus, a living plant always has embryonic tissues. By contrast, an animal embryo will very early produce all of the body parts that it will ever have in its life. When the animal is born, it has all its body parts and from that point will only grow larger and more mature. However, both plants and animals pass through a phylotypic stage that evolved independently and that causes a developmental constraint limiting morphological diversification.

<span class="mw-page-title-main">French flag model</span> Biological model

The French flag model is a conceptual definition of a morphogen, described by Lewis Wolpert in the 1960s. A morphogen is defined as a signaling molecule that acts directly on cells to produce specific cellular responses dependent on morphogen concentration. During early development, morphogen gradients generate different cell types in distinct spatial order. French flag patterning is often found in combination with others: vertebrate limb development is one of the many phenotypes exhibiting French flag patterning overlapped with a complementary pattern.

<span class="mw-page-title-main">Osteochondroprogenitor cell</span>

Osteochondroprogenitor cells are progenitor cells that arise from mesenchymal stem cells (MSC) in the bone marrow. They have the ability to differentiate into osteoblasts or chondrocytes depending on the signalling molecules they are exposed to, giving rise to either bone or cartilage respectively. Osteochondroprogenitor cells are important for bone formation and maintenance.

Epimorphosis is defined as the regeneration of a specific part of an organism in a way that involves extensive cell proliferation of somatic stem cells, dedifferentiation, and reformation, as well as blastema formation. Epimorphosis can be considered a simple model for development, though it only occurs in tissues surrounding the site of injury rather than occurring system-wide. Epimorphosis restores the anatomy of the organism and the original polarity that existed before the destruction of the tissue and/or a structure of the organism. Epimorphosis regeneration can be observed in both vertebrates and invertebrates such as the common examples: salamanders, annelids, and planarians.

References

  1. Li B, Carey M, Workman JL (February 2007). "The role of chromatin during transcription". Cell. 128 (4): 707–19. doi: 10.1016/j.cell.2007.01.015 . PMID   17320508.
  2. Heintzman ND, Stuart RK, Hon G, Fu Y, Ching CW, Hawkins RD, et al. (March 2007). "Distinct and predictive chromatin signatures of transcriptional promoters and enhancers in the human genome". Nature Genetics. 39 (3): 311–8. doi:10.1038/ng1966. PMID   17277777. S2CID   1595885.
  3. Meinhardt H, Gierer A (2000). "Pattern formation by local self-activation and lateral inhibition" (PDF). BioEssays. 22 (8): 753–760. CiteSeerX   10.1.1.477.439 . doi:10.1002/1521-1878(200008)22:8<753::aid-bies9>3.0.co;2-z. PMID   10918306. Archived (PDF) from the original on 2017-10-27.
  4. Sprinzak D, Lakhanpal A, Lebon L, Santat LA, Fontes ME, Anderson GA, et al. (May 2010). "Cis-interactions between Notch and Delta generate mutually exclusive signalling states". Nature. 465 (7294): 86–90. Bibcode:2010Natur.465...86S. doi:10.1038/nature08959. PMC   2886601 . PMID   20418862.
  5. Carlson BM (2007). Principles of Regenerative Biology. Burlington MA: Academic Press.
  6. Bosch TC (March 2007). "Why polyps regenerate and we don't: towards a cellular and molecular framework for Hydra regeneration". Developmental Biology. 303 (2): 421–33. doi: 10.1016/j.ydbio.2006.12.012 . PMID   17234176.
  7. 1 2 Reddien PW, Sánchez Alvarado A (2004). "Fundamentals of planarian regeneration". Annual Review of Cell and Developmental Biology. 20: 725–57. doi:10.1146/annurev.cellbio.20.010403.095114. PMID   15473858. S2CID   1320382.
  8. Wagner DE, Wang IE, Reddien PW (May 2011). "Clonogenic neoblasts are pluripotent adult stem cells that underlie planarian regeneration". Science. 332 (6031): 811–6. Bibcode:2011Sci...332..811W. doi:10.1126/science.1203983. PMC   3338249 . PMID   21566185.
  9. Nakamura T, Mito T, Bando T, Ohuchi H, Noji S (January 2008). "Dissecting insect leg regeneration through RNA interference". Cellular and Molecular Life Sciences. 65 (1): 64–72. doi:10.1007/s00018-007-7432-0. PMID   18030418.
  10. Simon A, Tanaka EM (2013). "Limb regeneration". Wiley Interdisciplinary Reviews. Developmental Biology. 2 (2): 291–300. doi:10.1002/wdev.73. PMID   24009038. S2CID   13158705.
  11. Slack JM (2013). "Chapter 20". Essential Developmental Biology. Oxford: Wiley-Blackwell.
  12. Jungnickel MK, Sutton KA, Florman HM (August 2003). "In the beginning: lessons from fertilization in mice and worms". Cell. 114 (4): 401–4. doi: 10.1016/s0092-8674(03)00648-2 . PMID   12941269.
  13. 1 2 Hackett JA, Sengupta R, Zylicz JJ, Murakami K, Lee C, Down TA, Surani MA (January 2013). "Germline DNA demethylation dynamics and imprint erasure through 5-hydroxymethylcytosine". Science. 339 (6118): 448–52. Bibcode:2013Sci...339..448H. doi:10.1126/science.1229277. PMC   3847602 . PMID   23223451.
  14. Hajkova P, Jeffries SJ, Lee C, Miller N, Jackson SP, Surani MA (July 2010). "Genome-wide reprogramming in the mouse germ line entails the base excision repair pathway". Science. 329 (5987): 78–82. Bibcode:2010Sci...329...78H. doi:10.1126/science.1187945. PMC   3863715 . PMID   20595612.
  15. Steven DH, ed. (1975). Comparative Placentation. London: Academic Press.
  16. Kimelman D, Martin BL (2012). "Anterior-posterior patterning in early development: three strategies". Wiley Interdisciplinary Reviews. Developmental Biology. 1 (2): 253–66. doi:10.1002/wdev.25. PMC   5560123 . PMID   23801439.
  17. Slack JM (1987). "Morphogenetic gradients - past and present". Trends in Biochemical Sciences. 12: 200–204. doi:10.1016/0968-0004(87)90094-6.
  18. Rogers KW, Schier AF (2011). "Morphogen gradients: from generation to interpretation". Annual Review of Cell and Developmental Biology. 27: 377–407. doi:10.1146/annurev-cellbio-092910-154148. PMID   21801015. S2CID   21477124.
  19. Dahmann C, Oates AC, Brand M (January 2011). "Boundary formation and maintenance in tissue development". Nature Reviews. Genetics. 12 (1): 43–55. doi:10.1038/nrg2902. PMID   21164524. S2CID   1805261.
  20. Hardin J, Walston T (August 2004). "Models of morphogenesis: the mechanisms and mechanics of cell rearrangement". Current Opinion in Genetics & Development. 14 (4): 399–406. doi:10.1016/j.gde.2004.06.008. PMID   15261656.
  21. Hammerschmidt M, Wedlich D (November 2008). "Regulated adhesion as a driving force of gastrulation movements". Development. 135 (22): 3625–41. doi: 10.1242/dev.015701 . PMID   18952908.
  22. Farge, Emmanuel (2003). "Mechanical induction of twist in the Drosophila foregut/stomodeal primordium". Current Biology. 13 (16): 1365–1377. doi: 10.1016/s0960-9822(03)00576-1 . PMID   1293230.
  23. Brunet, Thibaut; Bouclet, Adrien; et, al (2013). "Evolutionary conservation of early mesoderm specification by mechanotransduction in Bilateria". Nature Communications. 4: 2821. Bibcode:2013NatCo...4.2821B. doi:10.1038/ncomms3821. PMC   3868206 . PMID   24281726.
  24. Nguyen, Ngoc-Minh; Merle, Tatiana; et, al (2022). "Mechano-biochemical marine stimulation of inversion, gastrulation, and endomesoderm specification in multicellular Eukaryota". Frontiers in Cell and Developmental Biology. 10: 992371. doi: 10.3389/fcell.2022.992371 . PMC   9754125 . PMID   36531949.
  25. de Lussanet, M.H.E.; Osse, J.W.M. (2012). "An ancestral axial twist explains the contralateral forebain and the optic chiasm in vertebrates". Animal Biology. 62 (2): 193–216. arXiv: 1003.1872 . doi:10.1163/157075611X617102. S2CID   7399128.
  26. O'Farrell PH (2003). "How metazoans reach their full size: the natural history of bigness.". In Hall MN, Raff M, Thomas G (eds.). Cell Growth: Control of Cell Size. Cold Spring Harbor Laboratory Press. pp. 1–21.
  27. Moss EG, Romer-Seibert J (2014). "Cell-intrinsic timing in animal development". Wiley Interdisciplinary Reviews. Developmental Biology. 3 (5): 365–77. doi:10.1002/wdev.145. PMID   25124757. S2CID   29029979.
  28. Tata JR (1996). "Amphibian metamorphosis: an exquisite model for hormonal regulation of postembryonic development in vertebrates". Development, Growth and Differentiation. 38 (3): 223–231. doi:10.1046/j.1440-169x.1996.t01-2-00001.x. PMID   37281700. S2CID   84081060.
  29. Brown DD, Cai L (June 2007). "Amphibian metamorphosis". Developmental Biology. 306 (1): 20–33. doi:10.1016/j.ydbio.2007.03.021. PMC   1945045 . PMID   17449026.
  30. Cohen SM (1993). "Imaginal Disc Development.". In Bate M, Martinez-Arias M (eds.). The Development of Drosophila melanogaster. Cold Spring Harbor Press.
  31. Maves L, Schubiger G (October 2003). "Transdetermination in Drosophila imaginal discs: a model for understanding pluripotency and selector gene maintenance". Current Opinion in Genetics & Development. 13 (5): 472–9. doi:10.1016/j.gde.2003.08.006. PMID   14550411.
  32. Bäurle I, Laux T (October 2003). "Apical meristems: the plant's fountain of youth". Review. BioEssays. 25 (10): 961–70. doi:10.1002/bies.10341. PMID   14505363.
  33. Leopold AC (1964). Plant Growth and Development . New York: McGraw-Hill. p.  183.
  34. Brand U, Hobe M, Simon R (February 2001). "Functional domains in plant shoot meristems". Review. BioEssays. 23 (2): 134–41. doi:10.1002/1521-1878(200102)23:2<134::AID-BIES1020>3.0.CO;2-3. PMID   11169586. S2CID   5833219.
  35. Barlow P (May 2005). "Patterned cell determination in a plant tissue: the secondary phloem of trees". BioEssays. 27 (5): 533–41. doi:10.1002/bies.20214. PMID   15832381.
  36. Pacifici E, Di Mambro R, Dello Ioio R, Costantino P, Sabatini S (August 2018). "Arabidopsis root". The EMBO Journal. 37 (16). doi:10.15252/embj.201899134. PMC   6092616 . PMID   30012836.
  37. Ross SD, Pharis RP, Binder WD (1983). "Growth regulators and conifers: their physiology and potential uses in forestry.". In Nickell LG (ed.). Plant growth regulating chemicals. Vol. 2. Boca Raton, FL: CRC Press. pp. 35–78.
  38. Jin J, He K, Tang X, Li Z, Lv L, Zhao Y, et al. (July 2015). "An Arabidopsis Transcriptional Regulatory Map Reveals Distinct Functional and Evolutionary Features of Novel Transcription Factors". Molecular Biology and Evolution. 32 (7): 1767–73. doi:10.1093/molbev/msv058. PMC   4476157 . PMID   25750178. Archived from the original on 2016-06-02.
  39. Pires ND, Dolan L (February 2012). "Morphological evolution in land plants: new designs with old genes". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 367 (1588): 508–518. doi:10.1098/rstb.2011.0252. PMC   3248709 . PMID   22232763.
  40. 1 2 3 4 5 6 Friedman, William E. (1999). "Expression of the cell cycle in sperm of Arabidopsis: implications for understanding patterns of gametogenesis and fertilization in plants and other eukaryotes". Development . The Company of Biologists. 126 (5): 1065–75. doi:10.1242/dev.126.5.1065. ISSN   0950-1991. PMID   9927606. S2CID   13397345.
  41. Nieuwkoop PD, Faber J (1967). Normal table of Xenopus laevis (Daudin). North-Holland, Amsterdam.{{cite book}}: CS1 maint: location missing publisher (link)
  42. Harland RM, Grainger RM (December 2011). "Xenopus research: metamorphosed by genetics and genomics". Trends in Genetics. 27 (12): 507–15. doi:10.1016/j.tig.2011.08.003. PMC   3601910 . PMID   21963197.
  43. Lawson ND, Wolfe SA (July 2011). "Forward and reverse genetic approaches for the analysis of vertebrate development in the zebrafish". Developmental Cell. 21 (1): 48–64. doi: 10.1016/j.devcel.2011.06.007 . PMID   21763608.
  44. Rashidi H, Sottile V (April 2009). "The chick embryo: hatching a model for contemporary biomedical research". BioEssays. 31 (4): 459–65. doi:10.1002/bies.200800168. PMID   19274658. S2CID   5489431.
  45. Behringer R, Gertsenstein M, Vintersten K, Nagy M (2014). Manipulating the Mouse Embryo. A Laboratory Manual (Fourth ed.). Cold Spring Harbor, NY: Cold Spring Harbor Laboratory Press.
  46. St Johnston D (March 2002). "The art and design of genetic screens: Drosophila melanogaster". Nature Reviews. Genetics. 3 (3): 176–88. doi:10.1038/nrg751. PMID   11972155. S2CID   195368351.
  47. Riddle DL, Blumenthal T, Meyer BJ, Priess JR (1997). C.elegans II. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory Press.
  48. Ettensohn CA, Sweet HC (2000). "Patterning the early sea urchin embryo" . Current Topics in Developmental Biology Volume 50. Vol. 50. Academic Press. pp.  1–44. doi:10.1016/S0070-2153(00)50002-7. ISBN   9780121531508. PMID   10948448.{{cite book}}: |journal= ignored (help)
  49. Lemaire P (June 2011). "Evolutionary crossroads in developmental biology: the tunicates". Development. 138 (11): 2143–52. doi: 10.1242/dev.048975 . PMID   21558365.
  50. Nacu E, Tanaka EM (2011). "Limb regeneration: a new development?". Annual Review of Cell and Developmental Biology. 27: 409–40. doi:10.1146/annurev-cellbio-092910-154115. PMID   21801016.
  51. Ader M, Tanaka EM (December 2014). "Modeling human development in 3D culture". Current Opinion in Cell Biology. 31: 23–8. doi:10.1016/j.ceb.2014.06.013. PMID   25033469.
  52. Weigel D, Glazebrook J (2002). Arabidopsis. A Laboratory Manual. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory Press.

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