A stepwise epigenetic process controls immunoglobulin allelic exclusion

2004 ◽  
Vol 4 (10) ◽  
pp. 753-761 ◽  
Author(s):  
Yehudit Bergman ◽  
Howard Cedar
Keyword(s):  
Allelic Exclusion ◽  
Epigenetic Process ◽  
Process Controls

Nature or Nurture? No—Development Is an Epigenetic Process

PsycCRITIQUES ◽  
2005 ◽  
Vol 50 (19) ◽  
Author(s):  
Theresa A. Thorkildsen
Keyword(s):  
Epigenetic Process

Ectopic Transcript Analysis Indicates that Allelic Exclusion is an Important Cause of Type I Protein C Deficiency in Patients with Nonsense and Frameshift Mutations in the PROC Gene

1996 ◽  
Vol 75 (06) ◽  
pp. 870-876 ◽  
Author(s):  
José Manuel Soria ◽  
Lutz-Peter Berg ◽  
Jordi Fontcuberta ◽  
Vijay V Kakkar ◽  
Xavier Estivill ◽  
...  
Keyword(s):  
Splice Site ◽  
Protein C ◽  
Stop Codon ◽  
Premature Stop Codon ◽  
Allelic Exclusion ◽  
Polymorphism Analysis ◽  
Type I ◽  
Protein C Deficiency ◽  
Nonsense Mutations ◽  
Stop Codons

SummaryNonsense mutations, deletions and splice site mutations are a common cause of type I protein C deficiency. Either directly or indirectly by altering the reading frame, these' lesions generate or may generate premature stop codons and could therefore be expected to result in premature termination of translation. In this study, the possibility that such mutations could instead exert their pathological effects at an earlier stage in the expression pathway, through “allelic exclusion” at the RNA level, was investigated. Protein C (PROC) mRNA was analysed in seven Spanish type I protein C deficient patients heterozygous for two nonsense mutations, a 7bp deletion, a 2bp insertion and three splice site mutations. Ectopic RNA transcripts from patient and control lymphocytes were analysed by RT-PCR and direct sequencing of amplified PROC cDNA fragments. The nonsense mutations and the deletion were absent from the cDNAs indicating that only mRNA derived from the normal allele had been expressed. Similarly for the splice site mutations, only normal PROC cDNAs were obtained. In one case, exclusion of the mutated allele could be confirmed by polymorphism analysis. In contrast to these six mutations, the 2 bp insertion was not associated with loss of mRNA from the mutated allele. In this case, cDNA analysis revealed the absence of 19 bases from the PROC mRNA consistent with the generation and utilization of a cryptic splice site 3’ to the site of mutation, which would result in a frameshift and a premature stop codon. It is concluded that allelic exclusion is a common causative mechanism in those cases of type I protein C deficiency which result from mutations that introduce premature stop codons

Waddington’s Processual Epigenetics and the Debate over Cryptic Variability

2018 ◽  
Author(s):  
Flavia Fabris
Keyword(s):  
Genetic Variation ◽  
Evolutionary Biology ◽  
Modern Synthesis ◽  
Genetic Assimilation ◽  
Ontological Difference ◽  
Epigenetic Process ◽  
Recent Debate ◽  
Acquired Characters

This chapter reappraises Waddington’s processual theory of epigenetics and examines its implications for contemporary evolutionary biology. It focuses in particular on the ontological difference between two conflicting assumptions that have been conflated in the recent debate over the nature of cryptic variability: a substance view that is consistent with the modern synthesis and construes variability as a preexisting pool of random genetic variation; and a processual view, which derives from Waddington’s conception of developmental canalization and understands variability as an epigenetic process. The chapter also discusses how these opposing interpretations fare in their capacity to explain the genetic assimilation of acquired characters.

Sign in / Sign up

Export Citation Format

Share Document