ব্যবহারকারী:Lazy-restless/Developmental biology - উইকিপিডিয়া
ব্যবহারকারী:Lazy-restless/Developmental biology
সাময়িকীর জন্য, ডেভেলাপমেন্টাল বায়োলজি (সাময়িকী) দেখুন।
১ দৃষ্টিকোণসমূহ
২ পরিস্ফুটন প্রক্রিয়াসমূহ
২.১ কোষ পৃথকীকরণ
২.২ পুনর্গঠন
৩ প্রাণীদের ভ্রুনীয় পরিস্ফুটন
৪ উদ্ভিদের পরিস্ফুটন
৪.১ বৃদ্ধি
৪.২ অঙ্গসংস্থানিক পার্থক্য
৪.৩ উদ্ভিজ্জ অঙ্গসংস্থানের বিবর্তন
৫ পরিস্ফুটনীয় আদর্শ জীব
দৃষ্টিকোণসমূহ[সম্পাদনা]
পরিস্ফুটন প্রক্রিয়াসমূহ[সম্পাদনা]
কোষ পৃথকীকরণ[সম্পাদনা]
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 cell. 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.[১][২] 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,[৩] based on the properties of the Notch signaling pathway.[৪] 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.
পুনর্গঠন[সম্পাদনা]
Regeneration indicates the ability to regrow a missing part.[৫] 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,[৬] and planarian worms, which can usually regenerate both heads and tails.[৭] 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.[৮] 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,[৯] and the limbs of urodele amphibians.[১০] 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.[১১] 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.
প্রাণীদের ভ্রুনীয় পরিস্ফুটন[সম্পাদনা]
The sperm and egg fuse in the process of fertilization to form a fertilized egg, or zygote.[১২] 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. Morphogenetic movements convert the cell mass into a three layered structure consisting of multicellular sheets called ectoderm, mesoderm and endoderm, which 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,[১৩] and also establish differences of commitment along the anteroposterior axis (head, trunk and tail).[১৪]
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.[১৫][১৬] 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.[১৭] 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.[১৮][১৯] 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.
Growth in embryos is mostly autonomous.[২০] 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.[২১]
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,[২২][২৩] and the biology of the imaginal discs, which generate the adult body parts of the fly Drosophila melanogaster.[২৪][২৫]
উদ্ভিদের পরিস্ফুটন[সম্পাদনা]
আরও তথ্যের জন্য দেখুন: Plant development
Plants constantly produce new tissues and structures throughout their life from meristems[২৬] 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."[২৭]
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.[২৮] 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.[২৯]
Plant growth and development are mediated by specific plant hormones and plant growth regulators (PGRs) (Ross et al. 1983).[৩০] 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.
অঙ্গসংস্থানিক পার্থক্য[সম্পাদনা]
উদ্ভিজ্জ অঙ্গসংস্থানের বিবর্তন[সম্পাদনা]
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.[৩১]
পরিস্ফুটনীয় আদর্শ জীব[সম্পাদনা]
Frog: Xenopus (X.laevis and tropicalis).[৩২][৩৩] Good embryo supply. Especially suitable for microsurgery.
Zebrafish: Danio rerio.[৩৪] Good embryo supply. Well developed genetics.
Chicken: Gallus gallus.[৩৫] Early stages similar to mammal, but microsurgery easier. Low cost.
Mouse: Mus musculus.[৩৬] A mammal with well developed genetics.
Fruit fly: Drosophila melanogaster.[৩৭] Good embryo supply. Well developed genetics.
Nematode: Caenorhabditis elegans.[৩৮] Good embryo supply. Well developed genetics. Low cost.
Also popular for some purposes have been sea urchins[৩৯] and ascidians.[৪০] For studies of regeneration urodele amphibians such as the axolotl Ambystoma mexicanum are used,[৪১] and also planarian worms such as Schmidtea mediterranea.[৪২] Organoids have also been demonstrated as an efficient model for development.[৪৩] Plant development has focused on the thale cress Arabidopsis thaliana as a model organism.[৪৪]
↑ Li B.; Carey M.; Workman J.L. (২০০৭)। "The role of chromatin during transcription"। Cell। 128: 707–719। doi:10.1016/j.cell.2007.01.015। PMID 17320508। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Heintzman N.D.; ও অন্যান্য (২০০৭)। "Distinct and predictive chromatin signatures of transcriptional promoters and enhancers in the human genome"। Nat Genet। 39: 311–318। doi:10.1038/ng1966। PMID 17277777। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Meinhardt H., Gierer A. (২০০০)। "Pattern formation by local self-activation and lateral inhibition"। BioEssays। 22: 753–760। doi:10.1002/1521-1878(200008)22:8<753::aid-bies9>3.0.co;2-z। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Sprinzak D.; ও অন্যান্য (২০১০)। "Cis-interactions between Notch and Delta generate mutually exclusive signalling states"। Nature। 465: 86–90। doi:10.1038/nature08959। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Bosch T.C.G. (২০০৭)। "Why polyps regenerate and we don't: Towards a cellular and molecular framework for Hydra regeneration"। Developmental Biology। 303: 421–433। doi:10.1016/j.ydbio.2006.12.012। PMID 17234176। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Reddien P.W., Alvarado A.S. (২০০৪)। "Fundamentals of planarian regeneration"। Annual Review of Cell and Developmental Biology। 20: 725–757। doi:10.1146/annurev.cellbio.20.010403.095114। PMID 15473858। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Wagner D.E.; Wang I.E.; Reddien P.W. (২০১১)। "Clonogenic Neoblasts Are Pluripotent Adult Stem Cells That Underlie Planarian Regeneration"। Science। 332: 811–816। doi:10.1126/science.1203983। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Nakamura T.; ও অন্যান্য (২০০৮)। "Dissecting insect leg regeneration through RNA interference"। Cellular and Molecular Life Sciences। 65: 64–72। doi:10.1007/s00018-007-7432-0। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Simon A., Tanaka E.M. (২০১৩)। "Limb regeneration"। Wiley Interdisciplinary Reviews-Developmental Biology। 2: 291–300। doi:10.1002/wdev.73। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Jungnickel M.K.; Sutton K.A.; Florman H.M. (২০০৩)। "In the beginning: lessons from fertilization in mice and worms"। Cell। 114: 401–404। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Kimelman D., Martin B.L. (২০১২)। "Anterior-posterior patterning in early development: three strategies"। Wiley Interdisciplinary Reviews-Developmental Biology। 1: 253–266। doi:10.1002/wdev.25। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Slack J.M.W. (১৯৮৭)। "Morphogenetic gradients - past and present"। Trends in Biochemical Sciences। 12: 200–204। doi:10.1016/0968-0004(87)90094-6। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Rogers K. W., Schier A. F. (২০১১)। "Morphogen Gradients: From Generation to Interpretation"। Annual Review of Cell and Developmental Biology। 27: 377–407। doi:10.1146/annurev-cellbio-092910-154148। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Dahmann C.; Oates A. C.; Brand M. (২০১১)। "Boundary formation and maintenance in tissue development"। Nat Rev Genet। 12: 43–55। doi:10.1038/nrg2902। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Hardin J., Walston T. (২০০৪)। "Models of morphogenesis: the mechanisms and mechanics of cell rearrangement"। Current Opinion in Genetics and Development। 14: 399–406। doi:10.1016/j.gde.2004.06.008। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Hammerschmidt M., Wedlich D. (২০০৮)। "Regulated adhesion as a driving force of gastrulation movements"। Development। 135: 3625–3641। doi:10.1242/dev.015701। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Moss E.G., Romer-Seibert J. (২০১৪)। "Cell-intrinsic timing in animal development"। Wiley Interdisciplinary Reviews-Developmental Biology। 3: 365–377। doi:10.1002/wdev.145। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Tata J.R. (১৯৯৬)। "Amphibian metamorphosis: an exquisite model for hormonal regulation of postembryonic development in vertebrates"। Dev. Growth Diffn। 38: 223–231। doi:10.1046/j.1440-169x.1996.t01-2-00001.x। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Brown D.D., Cai L. (২০০৭)। "Amphibian metamorphosis"। Developmental Biology। 306: 20–33। doi:10.1016/j.ydbio.2007.03.021। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Maves L., Schubiger G. (২০০৩)। "Transdetermination in Drosophila imaginal discs: a model for understanding pluripotency and selector gene maintenance"। Current Opinion in Genetics & Development। 13: 472–479। doi:10.1016/j.gde.2003.08.006। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Bäurle, I; Laux, T (২০০৩)। "Apical meristems: The plant's fountain of youth"। BioEssays। 25 (10): 961–70। doi:10.1002/bies.10341। PMID 14505363। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link) Review.
↑ Brand, U; Hobe, M; Simon, R (২০০১)। "Functional domains in plant shoot meristems"। BioEssays। 23 (2): 134–41। doi:10.1002/1521-1878(200102)23:2<134::AID-BIES1020>3.0.CO;2-3। PMID 11169586। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link) Review.
↑ Barlow, P (২০০৫)। "Patterned cell determination in a plant tissue: The secondary phloem of trees"। BioEssays। 27 (5): 533–41। doi:10.1002/bies.20214। PMID 15832381। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Jin JP; ও অন্যান্য (জুলাই ২০১৫)। "An Arabidopsis transcriptional regulatory map reveals distinct functional and evolutionary features of novel transcription factors"। Molecular Biology and Evolution। 32 (7): 1767–1773। doi:10.1093/molbev/msv058। PMID 25750178। পিএমসি 4476157  । উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link) উদ্ধৃতি শৈলী রক্ষণাবেক্ষণ: ও অন্যান্য স্পষ্টভাবে ব্যবহার করছে (link)
↑ Harland R.M., Grainger R.M. (২০১১)। "Xenopus research: metamorphosed by genetics and genomics"। Trends in Genetics। 27: 507–515। doi:10.1016/j.tig.2011.08.003। PMID 21963197। পিএমসি 3601910  । উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Lawson N. D., Wolfe S. A. (২০১১)। "Forward and Reverse Genetic Approaches for the Analysis of Vertebrate Development in the Zebrafish"। Developmental Cell। 21: 48–64। doi:10.1016/j.devcel.2011.06.007। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Hassan Rashidi V.S. (২০০৯)। "The chick embryo: hatching a model for contemporary biomedical research"। BioEssays। 31: 459–465। doi:10.1002/bies.200800168। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ St Johnston D (২০০২)। "The art and design of genetic screens: Drosophila melanogaster"। Nat Rev Genet। 3: 176–188। doi:10.1038/nrg751। PMID 11972155। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Ettensohn C.A., Sweet H.C. (২০০০)। "Patterning the early sea urchin embryo"। Curr. Top. Dev. Biol.। 50: 1–44। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Lemaire P (২০১১)। "Evolutionary crossroads in developmental biology: the tunicates"। Development। 138: 2143–2152। doi:10.1242/dev.048975। PMID 21558365। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Nacu E., Tanaka E.M. (২০১১)। "Limb Regeneration: A New Development?"। Annual Review of Cell and Developmental Biology। 27: 409–440। doi:10.1146/annurev-cellbio-092910-154115। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
↑ Ader M., Tanaka E. M. (২০১৪)। "Modeling human development in 3D culture"। Current Opinion in Cell Biology। 31: 23–28। doi:10.1016/j.ceb.2014.06.013। উদ্ধৃতি টেমপ্লেট ইংরেজি প্যারামিটার ব্যবহার করেছে (link)
উইকিবইয়ে এই বিষয়ের উপরে আরো তথ্য রয়েছে: Lazy-restless/Developmental biology
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