Heterochromatin formation at telomeres and silent mating-type loci in yeast relies on an overlapping set of genes known as silent information regulators (SIR genes).

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#Id: 1025

#Unit 5. Developmental Biology

In mammals, Noggin (antagonist of BMP) is expressed in the notochord and neural folds.

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#Id: 1026

#Unit 5. Developmental Biology

Neural plate formation follow the principle of development:  often the signals promoting the specification of one cell type also block the specification of an alternative cell type.

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#Id: 1027

#Unit 5. Developmental Biology

The cells of the neural plate expresses:  Sox family of transcription factors (Sox1, 2, and 3)

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#Id: 1028

#Unit 5. Developmental Biology

Sox family of transcription factors

Inhibit the formation of epidermis and neural crest by blocking the transcription and signaling of BMPs

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#Id: 1029

#Unit 5. Developmental Biology

There are two principal modes of neurulation: 

1. Primary neurulation

2. Secondary neurulation

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#Id: 1030

#Unit 5. Developmental Biology

In primary neurulation, 

cells surrounding the neural plate direct the neural plate cells to proliferate, invaginate into the body, and separate from the surface ectoderm to form an underlying hollow tube.