BI236 Lecture Notes - Lecture 11: Cellular Differentiation, Gene Duplication, African Clawed Frog
Document Summary
The regulation of gene expression: regulation is an important aspect of almost every process in nature, especially gene expression, selective gene expression allows cells to be efficient, synthesizing only what is needed for each cell type. Differentiation: differentiated cells are produced from groups of immature, non-specialized cells or undifferentiated cells called cell differentiation, eg. Early embryo produce all the cell types that make up the organism. Eukaryotic gene expression is regulated at five main levels. The overall pattern of gene expression results from controls exerted at several five different levels: genome, transcription, rna processing and export, translation, and, posttranslational events. Selective replication of specific genes rrna genes xenopus laevis (5. 8s, 18s, 28s rrnas: 500 genes in haploid genome, 4000-fold replication during oogenesis. 2 million copies in mature oocyte: gene deletion. Mammalian rbcs discard nuclei after enough hemoglobin mrna is made. Movement of dna segments from one location to another within the genome .
