1 Motor Control Chris Rorden Ataxia Apraxia Motor Neurons Coordination and Timing.
Timing and coordination of specific events are necessary ... · 3.Temperature and the availability...
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Copyright © Rebecca Rehder Wingerden Lecture Presentations for Biology Eighth Edition Neil Campbell and Jane Reece Pearson Education, Inc., publishing as Person Benjamin Cummings College Board, AP Biology Curriculum Framework 2012-2013 Many biological processes involved in growth, reproduction and dynamic homeostases include temporal regulation and coordination. (2.E.1) Big Idea 2: Cellular Processes 18.2-18.4 a. Observable cell differentiation results from the expression of genes for tissue specific proteins. Timing and coordination of specific events are necessary for the normal development of an organism, and these events are regulated by a variety of mechanisms (2.E.1) Differential gene expression- the expression of different genes by cells with the same genome. From fertilized egg to animal. It takes just four days for: (1) cell division, (2) differentiation, & (3) morphogenesis to transform each of the fertilized frog eggs into a tadpole. Copyright © 2012 Rebecca Rehder Wingerden Timing and coordination of specific events are necessary for the normal development of an organism, and these events are regulated by a variety of mechanisms (2.E.1) Induction by nearby cells. The cells at the bottom of the early embryo depicted here are releasing chemicals that signal nearby cells to change their gene expression. Sources of developmental information for the early embryo; internal and external Copyright © 2012 Rebecca Rehder Wingerden Cytoplasmic determinants in the egg. The unfertilized egg has molecules in its cytoplasm, encoded by the mother's genes, that influence development. Many of these cytoplasmic determinants are unevenly distributed in the egg. After fertilization and mitotic division, the cell nuclei of the embryo are exposed to different sets of cytoplasmic determinants and, as a result, express different genes. Timing and coordination of specific events are necessary for the normal development of an organism, and these events are regulated by a variety of mechanisms (2.E.1) organisms organ systems organs Tissue-specific proteins- are proteins that are found only in a specific cell type and they will give the cell its characteristic structure and function. Determination- signals from other cells lead to activation of a master regulatory gene. Differentiation- the master regulatory gene encodes a transcription factor that binds to specific control elements which further differentiate the cell. Totiopotent Pluripotent Inner Mass Cells Unipotent once differentiated Copyright © 2012 Rebecca Rehder Wingerden b. Induction of transcription factors (internal and external) during development results in sequential gene expression. 1. Homeotic genes are involved in developmental patterns and sequences, where, when and how body segments develop Timing and coordination of specific events are necessary for the normal development of an organism, and these events are regulated by a variety of mechanisms (2.E.1) Conservation of homeotic genes in a fruit fly and a mouse- Homeotic genes that control the form of anterior and posterior structures of the body occur in the same linear sequence on chromosomes in Drosophila and mice. Examples: Hox and ParaHox genes which are important for segmentation Copyright © 2012 Rebecca Rehder Wingerden 2. Embryonic induction in development results in the correct timing of events. Timing and coordination of specific events are necessary for the normal development of an organism, and these events are regulated by a variety of mechanisms (2.E.1) Y chromosome- one of the two sex-determining chromosomes in most mammals. It contains SRY gene Embryonic Induction- where one embryonic tissue influences the development of others Astyanax mexianus- cave dweller Eye growth is controlled in a large part by the lens. Astyanax mexianus- surface dweller http://www.newswise.com/articles/blind-cave-fish-grow-eyes-after-lens-transplant SRY gene- is the sex- determining gene of the Y chromosome in mammals. This gene encodes a transcription factor that makes a protein (testis- determine factor) which results in maleness. Lens Transplant Copyright © 2012 Rebecca Rehder Wingerden
Transcript of Timing and coordination of specific events are necessary ... · 3.Temperature and the availability...
Copyright © Rebecca Rehder Wingerden
Lecture Presentations for
Biology Eighth Edition
Neil Campbell and Jane Reece
Pearson Education, Inc., publishing as Person Benjamin Cummings College Board, AP Biology Curriculum Framework 2012-2013
Many biological processes involved in growth, reproduction and dynamic homeostases include temporal regulation and coordination. (2.E.1)
Big Idea 2: Cellular Processes
18.2-18.4
a. Observable cell differentiation results from the expression of genes for tissue specific proteins.
Timing and coordination of specific events are necessary for the normal development of an organism, and these events are regulated by a variety of mechanisms (2.E.1)
Differential gene expression- the expression of different genes by cells with the same genome.
From fertilized egg to animal. It takes just four days for: (1) cell division, (2) differentiation, & (3) morphogenesis to transform each of the fertilized frog eggs into a tadpole.
Copyright © 2012 Rebecca Rehder Wingerden
Timing and coordination of specific events are necessary for the normal development of an organism, and these events are regulated by a variety of mechanisms (2.E.1)
Induction by nearby cells. The cells at the bottom of the early embryo depicted here are releasing chemicals that signal nearby cells to change their gene expression.
Sources of developmental information for the early embryo; internal and external
Copyright © 2012 Rebecca Rehder Wingerden
Cytoplasmic determinants in the egg. The unfertilized egg has molecules in its cytoplasm, encoded by the mother's genes, that influence development. Many of these cytoplasmic determinants are unevenly distributed in the egg. After fertilization and mitotic division, the cell nuclei of the embryo are exposed to different sets of cytoplasmic determinants and, as a result, express different genes.
Timing and coordination of specific events are necessary for the normal development of an organism, and these events are regulated by a variety of mechanisms (2.E.1)
organismsorgan systems
organs
Tissue-specific proteins- are proteins that are found only in a specific cell type and they will give the cell its characteristic structure and function.
Determination- signals from other cells lead to activation of a master regulatory gene.
Differentiation- the master regulatory gene encodes a transcription factor that binds to specific control elements which further differentiate the cell.
Totiopotent
Pluripotent Inner Mass Cells
Unipotent once differentiated
Copyright © 2012 Rebecca Rehder Wingerden
b. Induction of transcription factors (internal and external) during development results in sequential gene expression.
1. Homeotic genes are involved in developmental patterns and sequences, where, when and how body segments develop
Timing and coordination of specific events are necessary for the normal development of an organism, and these events are regulated by a variety of mechanisms (2.E.1)
Conservation of homeotic genes in a fruit fly and a mouse- Homeotic genes that control the form of anterior and posterior structures of the body occur in the same linear sequence on chromosomes in Drosophila and mice.
Examples: Hox and ParaHox genes which are important for segmentation
Copyright © 2012 Rebecca Rehder Wingerden
2. Embryonic induction in development results in the correct timing of events.
Timing and coordination of specific events are necessary for the normal development of an organism, and these events are regulated by a variety of mechanisms (2.E.1)
Y chromosome- one of the two sex-determining chromosomes in most mammals. It contains SRY gene
Embryonic Induction- where one embryonic tissue influences the development of others
Astyanax mexianus- cave dwellerEye growth is controlled in a large part by the lens.
Astyanax mexianus- surface dweller
http://www.newswise.com/articles/blind-cave-fish-grow-eyes-after-lens-transplant
SRY gene- is the sex-determining gene of the Y chromosome in mammals. This gene encodes a transcription factor that makes a protein (testis-determine factor) which results in maleness.
Lens Transplant
Copyright © 2012 Rebecca Rehder Wingerden
3. Temperature and the availability of water determine seed germination in most plants.
Timing and coordination of specific events are necessary for the normal development of an organism, and these events are regulated by a variety of mechanisms (2.E.1)
Seed germination- the growth of an embryonic plant contained within a seed. Temperature, water, oxygen and sometimes light or darkens, are factors which affect seed germination.
Sunflower seedling, just three days after germination.
Dormancy- some seeds are dormant and will not germinate unless they are subjected to specific environmental conditions.
Role of Fire- Chaparral and closed-cone conifer communities, the seeds need fire to germinate.
Closed cone pinesChaparralCopyright © 2012 Rebecca Rehder Wingerden
4. Genetic mutations can result in abnormal development.
Timing and coordination of specific events are necessary for the normal development of an organism, and these events are regulated by a variety of mechanisms (2.E.1)
Human polysyndactyly in a baby’s food due to a homozygous mutation in a Hox gene- The Hox genes play various roles at several distinct points during limb pattern formation. A specific mutation in the HoxD13 gene results in human polysyndactyly.
Copyright © 2012 Rebecca Rehder Wingerden
5. Genetic transplantation experiments support the link between gene expression and normal development.
Timing and coordination of specific events are necessary for the normal development of an organism, and these events are regulated by a variety of mechanisms (2.E.1)
Abnormal pattern formation in Drosophila- Mutations in certain regulatory genes, called homeotic genes, caused a misplacement of structures in an animal. These micrographs contrast the head of the wild-type fly, bearing a pair of small antennae, with the of a homeotic mutant, bearing a pair of legs in place of antennae.
Copyright © 2012 Rebecca Rehder Wingerden
6. Genetic regulation by microRNAs plays an important role in the development of organisms and the control of cellular functions.
Timing and coordination of specific events are necessary for the normal development of an organism, and these events are regulated by a variety of mechanisms (2.E.1)
Regulation of gene expression by miRNA- RNA transcripts are processed into miRNA, which prevent expression of mRNA containing complementary sequences.
miRNA Protein Complex- (1993) is capable of binding to complementary sequences of mRNA molecule, effectively blocking translation or degrading the mRNA.
The stem-loop secondary structure of a pre-microRNA from Brassica oleracea.
Copyright © 2012 Rebecca Rehder Wingerden
c. Programmed cell death (apoptosis) plays a role in the normal development and differentiation.
• Morphogenesis of fingers and toes
Timing and coordination of specific events are necessary for the normal development of an organism, and these events are regulated by a variety of mechanisms (2.E.1)
Effect of apoptosis during paw development in the mouse- In mice, humans, and other mammals, as well as in land birds, the embryonic region that develops into feet or hands initially has a solid, plate-like structure. Apoptosis eliminates the cells in the interdigital regions, thus forming the digits. The embryonic mouse paws shown in these fluorescence light micrographs are stained so that cells undergoing apoptosis appear bright yellow. Apoptosis of cells begins at the margin of each interdigital region, peaks as the tissue in these regions is reduced, and is not longer visible when the interdigital tissue has been eliminated.
Week 10 of human pregnancy
Copyright © 2012 Rebecca Rehder Wingerden Copyright © 2012 Rebecca Rehder Wingerden
Timing and coordination of specific events are necessary for the normal development of an organism, and these events are regulated by a variety of mechanisms (2.E.1)
Molecular basis of apoptosis in C. elegans. Three proteins are critical to apoptosis and its regulation in nematode. Apoptosis is more complicated in mammals but involves proteins similar to those in the nematode.
Apoptosis genes- hid, grim, and reaper genes are controlled by miRNA.
http://biologie.univ-mrs.fr/upload/p100/miRNA_and_apoptosis.pdf
Drosophila embryo - stage 16
Timing and coordination of specific events are necessary for the normal development of an organism, and these events are regulated by a variety of mechanisms (2.E.1)
Bozeman Biology: Cellular Specialization (10:00 min.) http://www.bozemanscience.com/044-cellular-specialization
Bozeman Biology: Gene Regulation (10:00 min.) http://www.bozemanscience.com/031-gene-regulation
TED Med: Anthony Atala on growing new organs (17:00 min.) http://www.ted.com/talks/anthony_atala_growing_organs_engineering_tissue.html
Copyright © 2012 Rebecca Rehder Wingerden
Bozeman Biology: Mechanisms of Timing and Control (14:00 min.) http://www.bozemanscience.com/025-mechanisms-of-timing-and-control
