Category Archives: Abalone Withering Syndrome Phage ID

Abalone Withering Syndrome Phage ID

qPCR – LCM DNA

Ran three primer sets on laser capture microscopy (LCM) DNA samples from 2005 and 2007. Ran the following primer sets:

  • WSN1 (detects RLO)
  • RLOv_helicase (detects RLO phage)
  • XenoCal_prophage

The DNA samples were provided to me by Lisa. I’m not entirely sure of their history:

 

Master mix calcs (Google Sheets):

All samples were run in duplicate. Plate layout, cycling params, etc. are in the qPCR Reports (see Results below).

Standard curves:

Baseline threshold was manually set to 580 for the WSN1 samples, as previously determined by Lisa for this assay.

Baseline threshold was manually set to 580.5 for the RLOv DNA helicase samples, as previously determined by me on 20160128.

 

Results:

WSN1:

 

RLOv DNA helicase:

 

XenoCal prophage:

 

Summary table of all three genes in each sample. Unfortunately, I don’t fully understand the sample name nomenclature, so I can’t really come to any conclusions about the data. Will pass along to Carolyn, Lisa, and Stan.

It’s also important to note that, due to low sample volume, I did not quantify these samples. This is important because any samples listed below that are negative for all three genes can not be conclusively declared “negative”, since we can’t rule out the possibility that they simply lack any DNA.

Presumably they were quantified after their initial extraction?

SAMPLE WSN1 RLOv DNA HELICASE XC PROPHAGE
LCM New RLO 09 + + +
LCM ST RLO 09 - - -
LCM New 08:30-5 B + + +
LCM New 08:30-5 - - -
LCM ST 08:30-3 - - -
LCM WS RLO + - +

 

STANDARD, AMPLIFICATION, & MELT CURVES

 

WSN1

 

 


 

 

RLOv_DNA_helicase

 


 

 

XenoCal prophage

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Data Aggregation – Black Abalone qPCR Data for RLOv DNA helicase, WSN, & XC Prophage Portal Genes

Carolyn & Stand Langevin wanted some additional qPCR data for the three gene targets listed above from the 1st and 2nd black abalone experiments. I had previously aggregated dated for withering syndrome (WSN1) from the 1st black abalone experiment. Additionally, I ran qPCRs with RLOv DNA helicase and XC prophage portal genes on the black abalone samples from the 1st and 2nd experiments.

Below, is the mean Ct (Cq) and mean copy number (not applicable for XC prophage portal gene, since we don’t have a standard curve developed for this target yet) for each of the samples – sorted by abalone experiment, followed by sample accession number.

The quick summary is:

  • No phage (RLOv DNA helicase) detected in samples from 2nd black abalone experiment.
  • All but two samples (06:6-44 and 07:12-18) are positive for XC prophage portal gene.
  • Other than the 2nd black abalone experiment samples, all are positive for all three gene targets (except the two exceptions noted above).

Will email data/info to Carolyn and Stan.

I will also add this info to Lisa’s Google Sheet: Black Abalone: Expt 1 – WS & Phage. This sheet is a comprehensive collection of all the data accumulated (including histology scores, abalone gene targets, abalone morphology, etc) from the 1st abalone experiment.

 

Google Sheet: 20160425_black_ab_qPCR_gene_summaries

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qPCR – Black Abalone with XC Prophage Portal Primers

I accidentally skipped two samples from the 2nd black abalone experiment sample set that I qPCR’d last week, so I’m qPCRing them today.

Master mix calcs (Google Sheet): 20160425 – qPCR Black Abs XenoCal phage portal

All samples were run in duplicate.

Plate layout, cycling params, etc. can be seen in the qPCR Report (see Results below).

Results:
qPCR Report (PDF): Sam_2016-04-25 12-55-40_CC009827.pdf
qPCR Data File (CFX96): Sam_2016-04-25 12-55-40_CC009827.pcrd

Have amplification in both samples.

I will add this to a “master” spreadsheet that I’ve made containing qPCR data from three genes on ~20 samples from both the 1st and 2nd black abalone experiments.

 

 

 

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qPCR – Black Abalone with XC Prophage Portal Primers

Ran qPCR with black abalone samples from the 1st and 2nd experiments to see if the Xenocal prophage portal gene is detected.

Master mix calcs (Google Sheet): 20160421 – qPCR Black Abs XenoCal phage portal

All samples were run in duplicate.

Black abalone sample 08:13-2 was run as a positive control.

Plate layout, cycling params, etc. can be seen in the qPCR Report (see Results below).

Results:
qPCR Report (PDF): Sam_2016-04-21 14-11-09_CC009827.pdf
qPCR Data File (CFX): Sam_2016-04-21 14-11-09_CC009827.pcrd

Two samples failed to produce amplification: 06:6-44 and 07:12-18. All other samples amplified. Will compile this data with WSN and RLOv DNA helicase and send along to Carolyn and Stan.

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qPCR – WSN1 & RLOv DNA helicase on Black Abalone 2nd Experiment 08:13 Accessions

Checking DNA isolated earlier today from the 2nd black abalone experiment to see if withering syndrome (RLO) and/or the withering syndrome phage (RLOv) is detectable in these samples.

Master mix calcs

Standard curves

All samples were run in duplicate.

Plate layout, cycling params, etc. can be seen in the qPCR Report (see Results below).

Baseline thresholds were set to the following values for each assay (RLOv threshold determined by me on 20160128; WSN1 threshold determined by Lisa):

RLOv DNA helicase: 580.5

WSN1: 580

Results:

qPCR Report – RLOv DNA helicase (PDF): Sam_2016-04-21 12-39-33_CC009827_RLOv_DNA_helicase.pdf
qPCR Report – WSN1 (PDF): Sam_2016-04-21 12-39-33_CC009827_WSN.pdf
qPCR Data File (CFX): Sam_2016-04-21 12-39-33_CC009827.pcrd

RLOv DNA helicase does not amplify in any samples.

WSN1 amplifies in all samples.

All samples are RLO+/RLOv-, as seen in the previous set of 08:13 samples that I qPCR’d.

 

RLOv DNA Helicase Standard Curve

 

 

RLOv DNA Helicase Amplification (Green = Std Cuve, Blue = Samples)

 

 

 

WSN1 Standard Curve

 

WSN1 Amplification (Blue = Standard Curve, Magenta= Samples)

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DNA Isolation – Black Abalone 2nd Experiment 08:13 Accessions

Isolated DNA from EtOH-preserved black abalone digestive gland tissue from the 2nd black abalone experiment.

There’s some odd background in regards to these samples which I previously described here that might be worth reviewing.

DNA was isolated using the QIAamp Fast DNA Stool Kit (Qiagen). Tissues were weighed and briefly homogenized with a disposable pestle in InhibitEX Buffer. Manufacturer’s protocol was followed. DNA  was eluted in 100μL of Buffer ATE and quantified on the Roberts Lab Qubit3.0 (ThermoFisher) using 1μL with the Qubit dsDNA Broad Range assay.

Results:

Google Sheet: 20160421_DNA_isolation_08:13_subset

 

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qPCR – XenoCal Prophage Portal Primers on RLO/RLOv positive/negative samples

Stan Langevin and Carolyn wanted to see if this particular gene was found in the withering syndrome (RLO) or phage (RLOv) genomes. I previously identified 10 samples of each of the following combinations:

  • RLO-/RLOv-
  • RLO-/RLOv+
  • RLO+/RLOv-
  • RLO+/RLOv+

Master mix calcs are here (Google Sheet): 20160331 – qPCR Black Ab 08:13 XenoCal phage portal check

All samples were run in duplicate.

Plate layout, cycling params, etc can be viewed in the qPCR Report (see Results below).

Results:
qPCR Report (PDF): Sam_2016-03-31 08-51-11_CC009827.pdf
qPCR Data File (CFX): Sam_2016-03-31 08-51-11_CC009827.pcrd

The results are definitely interesting!

Quick summary: Amplification only seen in RLO+/RLOv- samples!

Oddly, there is no amplification in the other group of RLO+ samples (RLO+/RLOv+). Based on the fact that there is amplification in RLO+/RLOv- samples, which implies this prophage portal gene is present in withering syndrome, we would expect to also have amplification in the other group of samples that are positive for withering syndrome.

Compiled qPCR data with WSN1, RLOv_DNA_helicase, and XenoCal prophage portal gene (Google Sheet): 20160331_qPCR_summary_RLO_RLOv_pos_negs

 

Amplification Plots (PINK= RLO+/RLOv-, BLUE = RLO-/RLOv-; GREEN = RLO-/RLOv+; BLACK = RLO+/RLOv+)

 

Melt Curve Plots (see amplification plots for color scheme)

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Sample ID- XenoCal Prophage Portal Tests

Now that the XenoCal prophage portal primers appear to be in working order, Carolyn wants me to test them out on 10 samples with the following status':

  • RLO-/RLOv-
  • RLO-/RLOv+
  • RLO+/RLOv-
  • RLO+/RLOv+

In order to quickly identify samples with these qualifications, I ran a SQL query on the following spreadsheet that contain qPCR data for both withering syndrome (RLO) and the phage (RLOv):

I saved the following worksheets from the above Google Sheet as CSV files:

  • water 2010
  • water 2011

These were imported to SQLite as I’ve previously done.

The two sheets were renamed for use in SQLite, respectively:

  • AbEndoWater2010
  • AbEndoWater2011

Here are the four queries I ran to obtain the four combinations of RLO/RLOv samples listed above

RLO-/RLOv-

sqlite> SELECT '2011_H2O', "DNA Tube Label", "Mean Cq", "RLOv_mean_Cq" FROM AbEndoWater2011 WHERE "Mean Cq"=0 AND "RLOv_mean_Cq"=0

 

RLO-/RLOv+

sqlite> SELECT '2011_H2O', "DNA Tube Label", "Mean Cq", "RLOv_mean_Cq" FROM AbEndoWater2011 WHERE "Mean Cq"=0 AND "RLOv_mean_Cq">0

 

RLO+/RLOv-

sqlite> SELECT '2011_H2O', "DNA Tube Label", "Mean Cq", "RLOv_mean_Cq" FROM AbEndoWater2011 WHERE "Mean Cq">0 AND "RLOv_mean_Cq"=0

 

RLO+/RLOv+

sqlite> SELECT '2011_H2O', "DNA Tube Label", "Mean Cq", "RLOv_mean_Cq" FROM AbEndoWater2011 WHERE "Mean Cq">0 AND "RLOv_mean_Cq">0

 

Results:

It looks like we do not currently have 10 samples that are RLO+/RLOv-. I will contact Carolyn to see if she happens to know of any samples that are RLO+, but do not contain (or, should not) any RLOv.

The full list of results can be seen in the Google Sheet below.

Google Sheet: 20160322_RLO_RLOv_pos_negs

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qPCR – Repeat Phage Portal Primer Specificity Check

This should be the last time I run this for the time being. Re-running this with undiluted RLOv- samples to improve the melt curve resolution for better comparison to the RLOv+ melt curves.

See the earlier qPCR run for master mix calcs.

All samples were run in duplicate.

See the qPCR Report (see Results below) for plate layout, cycling params, etc.

Results:

qPCR Report (PDF): Sam_2016-03-17 13-30-29_CC009827.pdf
qPCR Data File (CFX): Sam_2016-03-17 13-30-29_CC009827.pcrd

These results are interesting and I believe they are real, as opposed to the confusing/conflicting information I got from the previous two qPCRs from earlier today with the phage portal gene primers.

The poor/confusing results from the two previous qPCR attempts seem to have stemmed from low sample concentration. Using undiluted RLOv- samples in this run has resulted in clear, definitive data.

The melt curves are of a single peak in all RLOv+ samples.

The phage portal gene is NOT detected in RLOv- samples. However, it is present in RLOv+ samples and at significantly lower abundance than the RLOv DNA helicase (DNA helicase comes up at ~23 Cqs in samples that have been diluted 1:1000, while the phage portal gene comes up at ~28 Cqs in UNDILUTED samples). Alternatively, it is possible that the phage portal qPCR is less efficient and/or is experiencing some sort of inhibition; both seem unlikely, though.

Will discuss with Carolyn to see if she wants to go forward with cloning/sequencing and construction of a plasmid standard curve for the phage portal gene.


qPCR Amplification Plots (DNA helicase in green; Phage portal gene in blue)

 


 

qPCR Amplification Plots of Phage Portal Gene

 

qPCR Melt Curves of Phage Portal Gene

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qPCR – Repeat Phage Portal Primer Specificity Check

Due to the odd (and poor) results from the first qPCR to look at this phage portal gene, I’m repeating the qPCR exactly, but have made fresh 1:1000 dilutions of the two RLOv+ samples (08:3-15, 08:3-16) with TE.

See the earlier qPCR run for master mix calcs.

All samples were run in duplicate.

See the qPCR Report (see Results below) for plate layout, cycling params, etc.

Results:

qPCR Report (PDF): Sam_2016-03-17 10-42-54_CC009827.pdf
qPCR Data File (CFX): Sam_2016-03-17 10-42-54_CC009827.pcrd

Firstly, the fresh dilutions resolved the issue with the poor amplification previously seen with the RLOv DNA helicase assay; they look perfect in this run.

Quick summary for the phage portal qPCR:

  • Amplification in all 4 samples (RLOv- & RLOv+).
  • Much, much earlier amplification in RLOv+ samples.
  • Good, single peaks in melt curves
  • RLOv+ and RLOv- samples show different temps for peaks in melt curves

If the phage portal gene was present in the RLOv, then we would expect the amplification (i.e. the Cq values) of DNA helicase and the phage portal gene to be extremely close. However, in the RLOv+ samples, there’s a ~1000-fold difference in DNA helicase/phage portal levels.

If the phage portal gene was present in just the RLO, then we would expect similar amplification (i.e. Cq values) in both RLOv+/- samples. However, we see an EXTREME difference in phage portal gene levels between RLOv+ samples and the RLO- samples (~10,000-fold difference in levels). If the phage portal gene was present in both RLOv+/- samples, then that could possibly help explain this difference, due to the massive phage load in the RLOv+ samples (based on DNA helicase data). However, this doesn’t seem to be the case…

We see two distinct melt curve peak temps between the RLOv+/- samples. If the phage portal gene was present in both sample types, then the RLOv+ samples should exhibit a dual peak in the melt curves. However, this is not the case. This is difficult to explain since the RLOv+ samples also contain RLOv- (i.e. the RLO bacteria) DNA. If the PCR product generated in the RLOv- samples is indeed distinct from that produced in the RLOv+ samples, then we should see that product in the melt curve of the RLOv+ samples, but we don’t.

I will repeat this qPCR using undiluted, source DNA from the RLOv- samples. This should shift their amplification ~10 Cq (a 10-fold difference in amplification equates to ~3.32 Cqs) earlier. This, in turn, will allow their signal to generate higher levels of fluorescence and, hopefully, increase the melt curve peak for a more accurate assessment of melt temp(s); just to make sure the melt temp is accurate.


 

qPCR Amplification Plots (DNA helicase in green; Phage portal gene in blue)


qPCR Amplification Plots of Phage Portal Gene

qPCR Melt Curves of Phage Portal Gene

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