Info table

This table contains information on different characteristics of SHM. For all characteristics information can be found for all sequences or only sequences of a certain (sub)class. All results are based on the sequences that passed the filter settings chosen on the start page of the SHM & CSR pipeline and only include details on the analysed region as determined by the setting of the sequence starts at filter. All data in this table can be downloaded via the “downloads” tab.

Mutation frequency:

These values give information on the level of SHM. More information on the values found in healthy individuals of different ages can be found in IJspeert and van Schouwenburg et al, PMID: 27799928

Number of mutations: Shows the number of total mutations / the number of sequenced bases (the % of mutated bases).

Median number of mutations: Shows the median % of SHM of all sequences.

Patterns of SHM:

These values give insights into the targeting and patterns of SHM. These values can give insight into the repair pathways used to repair the U:G mismatches introduced by AID. More information on the values found in healthy individuals of different ages can be found in IJspeert and van Schouwenburg et al, PMID: 27799928

Transitions: Shows the number of transition mutations / the number of total mutations (the percentage of mutations that are transitions). Transition mutations are C>T, T>C, A>G, G>A.

Transversions: Shows the number of transversion mutations / the number of total mutations (the percentage of mutations that are transitions). Transversion mutations are C>A, C>G, T>A, T>G, A>T, A>C, G>T, G>C.

Transitions at GC: Shows the number of transitions at GC locations (C>T, G>A) / the total number of mutations at GC locations (the percentage of mutations at GC locations that are transitions).

Targeting of GC: Shows the number of mutations at GC locations / the total number of mutations (the percentage of total mutations that are at GC locations).

Transitions at AT: Shows the number of transitions at AT locations (T>C, A>G) / the total number of mutations at AT locations (the percentage of mutations at AT locations that are transitions).

Targeting of AT: Shows the number of mutations at AT locations / the total number of mutations (the percentage of total mutations that are at AT locations).

RGYW: Shows the number of mutations that are in a RGYW motive / The number of total mutations (the percentage of mutations that are in a RGYW motive). RGYW motives are known to be preferentially targeted by AID (R=Purine, Y=pyrimidine, W = A or T).

WRCY: Shows the number of mutations that are in a WRCY motive / The number of total mutations (the percentage of mutations that are in a WRCY motive). WRCY motives are known to be preferentially targeted by AID (R=Purine, Y=pyrimidine, W = A or T).

WA: Shows the number of mutations that are in a WA motive / The number of total mutations (the percentage of mutations that are in a WA motive). It is described that polymerase eta preferentially makes errors at WA motives (W = A or T).

TW: Shows the number of mutations that are in a TW motive / The number of total mutations (the percentage of mutations that are in a TW motive). It is described that polymerase eta preferentially makes errors at TW motives (W = A or T).

Antigen selection:

These values give insight into antigen selection. It has been described that during antigen selection, there is selection against replacement mutations in the FR regions as these can cause instability of the B-cell receptor. In contrast replacement mutations in the CDR regions are important for changing the affinity of the B-cell receptor and therefore there is selection for this type of mutations. Silent mutations do not alter the amino acid sequence and therefore do not play a role in selection. More information on the values found in healthy individuals of different ages can be found in IJspeert and van Schouwenburg et al, PMID: 27799928

FR R/S: Shows the number of replacement mutations in the FR regions / The number of silent mutations in the FR regions (the number of replacement mutations in the FR regions divided by the number of silent mutations in the FR regions)

CDR R/S: Shows the number of replacement mutations in the CDR regions / The number of silent mutations in the CDR regions (the number of replacement mutations in the CDR regions divided by the number of silent mutations in the CDR regions)

Number of sequences nucleotides:

These values give information on the number of sequenced nucleotides.

Nt in FR: Shows the number of sequences bases that are located in the FR regions / The total number of sequenced bases (the percentage of sequenced bases that are present in the FR regions).

Nt in CDR: Shows the number of sequenced bases that are located in the CDR regions / The total number of sequenced bases (the percentage of sequenced bases that are present in the CDR regions).

A: Shows the total number of sequenced adenines / The total number of sequenced bases (the percentage of sequenced bases that were adenines).

C: Shows the total number of sequenced cytosines / The total number of sequenced bases (the percentage of sequenced bases that were cytosines).

T: Shows the total number of sequenced thymines / The total number of sequenced bases (the percentage of sequenced bases that were thymines).

G: Shows the total number of sequenced guanines / The total number of sequenced bases (the percentage of sequenced bases that were guanines).

Graphs

These graphs visualize information on the patterns and targeting of SHM and thereby give information into the repair pathways used to repair the U:G mismatches introduced by AID. The data represented in these graphs can be downloaded in the download tab. More information on the values found in healthy individuals of different ages can be found in IJspeert and van Schouwenburg et al, PMID: 27799928.

Percentage of mutations in AID and pol eta motives

Visualizes for each (sub)class the percentage of mutations that are present in AID (RGYW or WRCY) or polymerase eta motives (WA or TW) in the different subclasses (R=Purine, Y=pyrimidine, W = A or T).

Relative mutation patterns

Visualizes for each (sub)class the distribution of mutations between mutations at AT locations and transitions or transversions at GC locations.

Absolute mutation patterns

Visualized for each (sub)class the percentage of sequenced AT and GC bases that are mutated. The mutations at GC bases are divided into transition and transversion mutations.

Hanna IJspeert, Pauline A. van Schouwenburg, David van Zessen, Ingrid Pico-Knijnenburg, Gertjan J. Driessen, Andrew P. Stubbs, and Mirjam van der Burg (2016). Evaluation of the Antigen-Experienced B-Cell Receptor Repertoire in Healthy Children and Adults. In Frontiers in Immunolog, 7, pp. e410-410. [doi:10.3389/fimmu.2016.00410][Link]