Embryology workshops 1 +2 Flashcards
Explain the breif version of how mRNA is made from a gene?
Transcription factor binds to the promotor region
Primary transcript is formed by transcription
Undergoes splicing to remove introns
Addition of a 5’ cap and a poly A tail, this regulates mRNA translation, that will result in a protein
What makes up the structure of chromatin?
Nucleosomes (146bp) wrapped around histone proteins
Histones have tails that stick out from the complex
What is the function of histone tails?
The regions that are modified by epigenetics, undergo acetylation.
What is the difference between condensed and uncondensed histones?
Condensed nucelosomes - histone tails are largely methylated, compact complex
Uncondensed nucleosomes - histone tails are largerly acetylated, uncondensed complex
What is important to remember about histone modification?
There are many different types of chromatin compaction, each with different histone modifications.
What is the difference between hetero and euchrochromatin?
Heterochromatin - refers to chromatin that is highly condensed and is not readily available for transcription
Euchrochromatin - is not highly condensed and is easily accessible for transcription
What does collinearty mean in relation to hox genes?
They are arranged in the genome to reflect the order that they are expressed along the anterior/posterior axis of the body.
What is meant by a homeotic gene?
Regulates the development of anatomical structures in an organism.
They are typically regulatory genes, that act as transcription factors.
Give bodily sections an indentity.
What is the difference between patterning and segmentation?
Segmentation - splitting up into segments (indea that there are two different parts)
Patterning - identifying that a part will become a hand/leg, involves hox genes.
What is the difference between hox genes, homeotic genes and homeobox genes?
Hox genes - determine the identity of a segment
Homeotic genes - including hox genes, regulate organs that develop in the specific segment identity
Homeobox genes - includes homeotic genes, are a super family of transcription factors that regulate body plans and developmental control..
Why are enhancers and regulatory genes more important than the actual genes themsevles?
It is not how many genes we have but how we use them.
The same genes can be expressed in different regions, in different combinations with other genes and in different levels of expression
This is all regulated by enhancers.
What is the function of Pax6?
Expressed and functions in the lens, cornea, retina, neural tube and pancreas development.
Regulated by enhancers.
Mutations are responsible for malformations, often vision loss.
What is the legal time limit on growing a human embryo?
14 days.
However, since 2016 it is scientificially possible to grow an embryo past this stage.
Law in question due to the potentialy research and scientific gains from extending this time limit.
What is single cell transcriptomes?
What does analysising this tell us about cell identity?
Analysing the gene expression in one cell by comparing the level of mRNA
Differences between cells is due to different combinations and quantities of gene expression, not just the absence and presence of genes.
At what stage of gestation does it develop from an embryo to a foetus?
Embryo is week 3 to 8
A foetus is week 12 to 9 months
